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PLOS One logoLink to PLOS One
. 2020 Aug 13;15(8):e0237475. doi: 10.1371/journal.pone.0237475

Hypovascular tumors developed into hepatocellular carcinoma at a high rate despite the elimination of hepatitis C virus by direct-acting antivirals

Kazuaki Tabu 1,#, Seiichi Mawatari 1,*,#, Kohei Oda 1,, Kotaro Kumagai 1,, Yukiko Inada 2,, Hirofumi Uto 2,, Akiko Saisyoji 3,, Yasunari Hiramine 3,, Masafumi Hashiguchi 4,, Tsutomu Tamai 4,, Takeshi Hori 4,, Kunio Fujisaki 5,, Dai Imanaka 6,, Takeshi Kure 7,, Ohki Taniyama 1,, Ai Toyodome 1,, Sho Ijuin 1,, Haruka Sakae 1,, Kazuhiro Sakurai 8,, Akihiro Moriuchi 8,, Shuji Kanmura 1,, Akio Ido 1,#
Editor: Tatsuo Kanda9
PMCID: PMC7425876  PMID: 32790728

Abstract

Background and aims

Direct-acting antivirals (DAAs) against hepatitis C virus (HCV) exert high anti-HCV activity and are expected to show anti-inflammatory effects associated with HCV elimination. Furthermore, hepatocellular carcinoma (HCC) is known to dedifferentiate from hypovascular tumors, such as dysplastic nodules or well-differentiated HCC, to hypervascular tumors. We therefore explored whether or not DAAs can suppress the growth and hypervascularization of hypovascular tumors.

Methods

We enrolled 481 patients with HCV genotype 1 infection who were treated with Daclatasvir and Asunaprevir therapy. Of these, 29 patients had 33 hypovascular tumors, which were confirmed by contrast-enhanced MRI or CT before therapy. We prospectively analyzed the cumulative incidence of HCC, i.e. the growth or hypervascularization of hypovascular tumors, and compared the HCC development rates between patients with hypovascular tumors and those without any tumors.

Results

The mean size of the hypovascular tumors was 11.3 mm. Twenty seven of 29 patients who achieved an SVR had 31 nodules, 19 of 31 nodules (61.3%) showed tumor growth or hypervascularization, and 12 (38.7%) nodules showed no change or improvement. The cumulative incidence rates of tumor growth or hypervascularization were 19.4% at 1 year, 36.0% at 2 years, 56.6% at 3 years, and 65.3% at 4 years. Among the patients who achieved a sustained virologic response, the cumulative HCC development rates of patients with hypovascular tumors was significantly higher than in those without any tumors. A Cox proportional hazard analysis showed that a history of HCC therapy, the presence of a hypovascular tumor, and AFP >4.6 ng/mL at the end of treatment were independent risk factors for HCC development.

Conclusion

Hypovascular tumors developed into HCC at a high rate despite the elimination of HCV by DAAs. As patients with hypovascular tumors were shown to have a high risk of HCC development, they should undergo strict HCC surveillance.

Introduction

Liver cancer is the sixth-most commonly diagnosed cancer and the fourth leading cause of cancer death worldwide [1, 2]. The majority of primary liver cancer is hepatocellular carcinoma (HCC). HCC occurs in patients with underlying liver disease, mostly as a result of hepatitis B or C virus (HBV or HCV) infection or alcohol abuse [2]. The persistent inflammation caused by HCV infection causes liver fibrosis, leading to cirrhosis and HCC [3]. One of the goals of therapy is to cure HCV infection in order to prevent the complications of HCV-related liver diseases, including hepatic necroinflammation, fibrosis, cirrhosis, decompensated cirrhosis, HCC, and death [4].

HCC occurs as a result of hepatic inflammation and/or changes in the tumor microenvironment [2]. Interferon (IFN)-based therapy for chronic hepatitis C provides therapeutic benefits, such as the suppression of progressive fibrosis via HCV elimination, thereby preventing HCC [5, 6]. As a mechanism for suppressing hepatocarcinogenesis by IFN, the involvement of a direct antiviral effect and tumor-suppressive action through the induction of antitumor immunity have been considered [7, 8].

Direct-acting antivirals (DAAs) against HCV exert high anti-HCV activity via direct action on the viral protein to inhibit viral growth and replication, and are expected to show anti-inflammatory effects associated with HCV elimination [1]. Recently, some reports shows that DAA also prevent hepatocarcinogenesis in a manner similar to IFN [912].

Furthermore, HCC is known to dedifferentiate from hypovascular liver tumors (dysplastic nodules and well-differentiated HCC) to hypervascular tumors [13, 14]. With this rationale, we therefore examined whether or not DAAs can suppress the growth and hypervascularization of hypovascular liver tumors.

Materials and methods

Patients

Fig 1 shows the flow chart of study patient enrollment. We enrolled 481 patients with HCV genotype 1 infection who were treated with daclatasvir (DCV; Daklinza; Bristol-Myers Squibb, New York, NY, USA) at 60 mg/day once daily and asunaprevir (ASV; Sunvepra; Bristol-Myers Squibb) at 200 mg/day twice daily for 24 weeks, including patients who had previously undergone curative HCC therapy such as surgical resection or radio frequency ablation (RFA) and discontinued therapy due to adverse events, at 21 facilities belonging to the Kagoshima Liver Study Group in Japan, between September, 2014, and December, 2016. A sustained virologic response (SVR) was defined as undetectable HCV RNA at 24 weeks after the end of treatment.

Fig 1. Flow chart of study patient enrollment.

Fig 1

*underwent contrast-enhanced MRI or CT within two years before therapy or during DAA therapy.

Among these patients, 29 patients had hypovascular tumors that were confirmed by contrast-enhanced (CE) MRI or CT before therapy. These surveys were conducted approximately 50 days before therapy. They were prospectively observed every three to four months to assess the tumor size and hypervascularization status. HCC development was defined by 20% growth or hypervascularization of a hypovascular nodule. We analyzed the cumulative incidence rates of growth or hypervascularization of hypovascular nodules. In contrast, 452 patients were confirmed to be tumor-free by ultrasound sonography (US), CT, or MRI before DAA therapy and underwent HCC surveillance according to Japanese guidelines. These guidelines state that cirrhotic patients have an extremely high risk of developing HCC and should be monitored every three to four months and that non-cirrhotic patients have a high risk of developing HCC and should be monitored every six months by US, CT, or MRI [15]. HCC was diagnosed when typical vascular findings were observed by CE-CT or MRI, i.e. hyper-enhancement in the arterial phase and a washout pattern in the portal or delayed phase.

We analyzed the respective cumulative HCC development rates of patients with hypovascular tumors and those without any tumors. Among the patients who achieved an SVR, 168 without a hypovascular tumor underwent CE-MRI or CT within 2 year before therapy or during DAA therapy. We compared the cumulative HCC development rates between patients with and without hypovascular tumors. The Fib-4 index, a surrogate marker of liver fibrosis, was calculated based on the methods of a previous study [16]. The initiation of the observation period was defined as the initiation of DAA treatment.

The study protocol conformed to the ethical guidelines of the Declaration of Helsinki and was approved by Kagoshima University Hospital and the research ethics committee of each participating facility on December 10, 2014, and October 21, 2015 (approval number: 26–142, 26–143, and 27–118). Written informed consent was obtained from each patient.

Definition of hypovascular tumor

Hypovascular tumors were diagnosed by gadolinium ethoxybenzyl diethlenetriamine pentaacetic acid (Gd-EOB-DTPA) CE-MRI based on scans showing no intense enhancement in the arterial phase but a low signal intensity indicating a hypovascular liver tumor (i.e. dysplastic nodules and well-differentiated HCC) in the hepatobiliary phase or CE-CT showing no enhancement in the arterial phase but a low density in the arterial, portal, or delayed phase.

Detection of HCV resistance-associated substitutions (RAS)

As described in detail previously, we investigated the viral genome sequence by direct sequencing [1719]. The nucleotide sequences of the second amplicons were determined using a BigDye Terminator v3.1 Cycle Sequencing Kit (Thermo Fisher Scientific, Waltham, MA, USA) and Sanger sequencing. The sequences of the non-structural (NS) 3 and NS5A RAS positions in the HCV gene were determined using HCV-Con1 (accession no. AJ238799)

Statistical analyses

Statistical analyses were performed using the IBM Statistical Package for Social Sciences (SPSS) software program (version 22 IBM SPSS Statistics, Armonk, NY, USA). Categorical data were compared using the chi-squared test and Fisher's exact test, as appropriate. Continuous variables were analyzed using the Mann-Whitney U test. The Kaplan–Meier method and log rank test were used to analyze the cumulative HCC development rates. P values of <0.05 were considered to indicate statistical significance. Factors associated with HCC development were determined using a Cox proportional hazards analysis with forward selection using p<0.10 as a cutoff for inclusion in the model. For the categorical data, we determined the cut-off values at which the optimal sensitivity and specificity were achieved using receiver operating characteristic curves.

Results

Baseline characteristic of patients with hypovascular tumor

The baseline characteristic of patients with hypovascular tumors showed that the mean age was 73 years old, 34.5% were male, 79.3% had liver cirrhosis, and 41.4% had a history of HCC therapy. Thirty-three tumors were detected in 29 patients, and the mean hypovascular tumor size was 11.3 mm (Table 1). No patients had RAS of NS5A L31 or Y93 or NS3 D168 at baseline. Twenty-seven patients (93.1%) achieved an SVR.

Table 1. Baseline characteristic of patients with hypovascular tumors and without any tumor.

Total (n = 481) tumor(-) (n = 452) Hypovascular tumor(+) (n = 29) P value
Age, years 68.8±9.1 68.5±9.2 73.1±5.5 0.007
Male, n (%) 193 (40.1) 183 (40.5) 10 (34.5) 0.332
Liver cirrhosis, n (%) 133 (27.7) 110 (24.3) 23 (79.3) <0.001
History of interferon-based therapy, n (%) 255 (53.0) 236 (52.2) 19 (65.5) 0.373
History of HCC therapy, n (%) 53 (11.0) 41 (9.1) 12 (41.4) <0.001
Platelets, ×104/μL (n = 480) 13.6±5.5 13.9±5.4 9.6±5.0 <0.001
Total bilirubin, mg/dL (n = 480) 0.8±0.4 0.8±0.4 1.0±0.5 0.029
ALT, U/L 49±37 49±38 53±32 0.088
GGT, U/L (n = 480) 44±42 43±43 47±28 0.130
Albumin, g/dL (n = 468) 4.0±0.4 4.0±0.4 3.8±0.6 0.007
Hyaluronic acid, ng/mL (n = 413) 225±389 214±383 431±446 0.001
Fib-4 index (n = 480) 4.69±3.33 4.50±3.21 7.52±3.93 <0.001
AFP (Before), ng/mL (n = 479) 12.4±30.3 11.8±30.4 22.6±26.1 <0.001
AFP (End of treatment), ng/mL (n = 453) 6.0±12.8 5.8±12.7 9.0±12.7 0.017
DCP, mAU/mL (n = 375) 21.4±11.2 20.8±10.1 28.7±20.5 0.069
SVR, n (%) 422 (87.7) 395 (87.4) 27 (93.1) 0.284
Hypovascular tumor size, mm (n = 33) - - 11.3±3.7 -
HCC development, n (%) 65 (13.5) 44 (9.7) 21 (72.4) <0.001

Data are shown as the mean ± standard deviation. HCC, hepatocellular carcinoma; ALT, alanine transaminase; GGT, γ-glutamyltransferase; AFP, α-fetoprotein; DCP, des-γ-carboxy prothrombin; SVR, sustained virologic response

On comparing the baseline characteristics between patients with hypovascular tumors and those without any tumors, the patients with hypovascular tumors tended to be older; more frequently had liver cirrhosis and a history of HCC therapy; and had higher values of total bilirubin, hyaluronic acid, Fib-4 index, and AFP before therapy and at the end of treatment and lower platelet counts and albumin levels than those without any tumors (Table 1).

Outcomes of hypovascular tumors in patients who achieved an SVR

Fig 2 shows the outcomes of hypovascular tumors in patients who achieved an SVR. In 27 of 29 patients with hypovascular tumors who achieved an SVR, 4 patients had 2 hypovascular tumors each, resulting in 31 hypovascular tumors in total. Of these 31 nodules, 19 (61.3%) showed tumor growth or hypervascularization, while 12 (38.7%) showed no change or improvement. Among the patients with two hypovascular tumors, both tumors in two patients showed no change, while the tumors in the other two patients showed hypervascularization in one nodule and no change in the other. Two patients developed HCC in other lesions, but the hypovascular tumor did not change. Three nodules were treated by surgery, nine were treated by RFA, and seven were treated by transcatheter arterial chemoembolization (TACE). No statistically significant differences were observed between tumor growth or hypervascularization and no change or improvement regarding the hypovascular tumor size (10.4±2.5 mm vs. 12.2±4.7 mm, p = 0.318).

Fig 2. Outcome of hypovascular tumors in patients who achieved an SVR.

Fig 2

*Four patients had two hypovascular tumors each, and in two of these patients, one nodule showed hypervascularization, while the other nodule showed no change. **Two patients developed HCC in other lesions, but the hypovascular tumor did not change.

The cumulative incidence rates of growth or hypervascularization of hypovascular tumors

In patients who achieved an SVR, the cumulative incidence rates of growth or hypervascularization of hypovascular tumors were 19.4% at 1 year, 36.0% at 2 years, 56.6% at 3 years, and 65.3% at 4 years (Fig 3A). In addition, the respective cumulative HCC development rates of patients with and without a history of curative HCC therapy were 23.1% and 16.7% at 1 year, 55.1% and 22.2% at 2 years, 73.1% and 44.5% at 3 years, and 82.1% and 52.5% at 4 years, respectively (Fig 3B). There was no significant difference in patients with and without a history of curative HCC therapy (p = 0.113) (Fig 3B). In addition, there were no patients who had unexpected tumor growth during the observation periods.

Fig 3. Cumulative incidence rates of growth or hypervascularization of hypovascular tumor.

Fig 3

(a) Cumulative incidence rates of growth or hypervascularization of hypovascular tumors. (b) Cumulative incidence rates in patients with or without a history of HCC therapy.

The comparison of the incidence of HCC between patients with hypovascular tumors and without any tumors who achieved an SVR

We compared the incidence of HCC between patients with hypovascular tumors and those without any tumors who achieved an SVR. Overall, 422 patients (87.7%) achieved an SVR (including 36 patients discontinued therapy), and 56 developed HCC (Table 2). Among patients who achieved an SVR, a univariate analysis showed that patients who developed HCC were more frequently male and had liver cirrhosis, a history of HCC therapy, and lower platelet and albumin values and higher ALT, GGT, hyaluronic acid, fib-4 index, and AFP values before and at the end of treatment (Table 2).

Table 2. Baseline characteristics of patients who achieved an SVR.

Total (n = 422) HCC development(-) (n = 366) HCC development(+) (n = 56) P value
Age, years 68.8±9.2 68.5±9.5 70.8±7.4 0.120
Male, n (%) 177 (41.9) 147 (40.2) 30 (53.6) 0.041
Liver Cirrhosis, n (%) 109 (27.7) 79 (21.6) 30 (53.6) <0.001
History of interferon-based therapy, n (%) (n = 421) 218 (51.7) 181 (49.5) 37 (66.1) 0.066
History of HCC therapy, n (%) 46 (10.9) 19 (5.2) 27 (48.2) <0.001
Presence of hypovascular tumor, n (%) 27 (6.4) 7 (1.9) 20 (35.7) <0.001
Platelets, ×104/μL 13.7±5.5 14.1±5.4 11.2±5.4 <0.001
Total bilirubin, mg/dL 0.8±0.4 0.8±0.3 0.9±0.4 0.223
ALT, U/L 49±38 49±39 53±28 0.009
GGT, U/L (n = 421) 42±36 40±32 59±55 0.002
Albumin, g/dL (n = 412) 4.0±0.4 4.0±0.4 3.8±0.5 <0.001
Hyaluronic acid, ng/mL (n = 359) 230±411 213±390 347±526 <0.001
Fib-4 index 4.67±3.40 4.40±3.27 6.44±3.72 <0.001
AFP (Before), ng/mL (n = 420) 11.4±22.9 9.5±16.1 23.6±45.5 <0.001
AFP (End of treatment), ng/mL (n = 399) 5.7±12.3 5.1±12.1 9.2±12.9 <0.001
DCP, mAU/mL (n = 327) 21.7±11.7 20.9±11.0 26.2±14.5 0.069

Data are shown as the mean ± standard deviation.

HCC, hepatocellular carcinoma; ALT, alanine transaminase; GGT, γ-glutamyltransferase; AFP, α-fetoprotein; DCP, des-γ-carboxy prothrombin; SVR, sustained virologic response

We performed a multivariate analysis using factors that were significantly different in the univariate analysis as covariates. A Cox proportional hazard analysis showed that a history of HCC therapy, the presence of hypovascular tumor, and an AFP >4.6 ng/mL at the end of treatment were independent risk factors for HCC development (Table 3). Among patients without any tumors who achieved an SVR, 168 underwent CE-MRI or CT within 2 years before therapy or during DCV+ASV therapy (Fig 1). The patients who underwent CT or MRI before DAA therapy had higher rates of HCC development than those who underwent US alone. Because the patients who underwent CT or MRI more frequently had liver cirrhosis and a history of HCC therapy, had higher total bilirubin, GGT, hyaluronic acid, Fib-4 index, and AFP values before therapy and at the end of treatment, and had lower platelet counts and albumin levels than those who underwent US alone (S1 Table). We performed a Cox proportional hazard analysis in patients who underwent CE-MRI or CT including hypovascular tumors, and similar results were obtained (Table 3).

Table 3. Factors associated with HCC development.

Category Cut off Multivariate analysis
Hazard Ratio 95% CI P value
Among the patients who achieved SVR (n = 331)
Sex Male 1.754 0.959–3.210 0.068
History of HCC therapy Yes 6.947 3.685–13.099 <0.001
Hypovascular tumor Presence 5.119 2.566–10.210 <0.001
AFP level at end of treatment >4.6 ng/mL 2.377 1.298–4.353 0.005
Among the patients who achieved SVR and underwent contrast-enhanced MRI or CT within 2 year before therapy or during DAA therapy (n = 156)
History of HCC therapy Yes 5.200 2.671–10.125 <0.001
Hypovascular tumor Presence 4.097 2.038–8.237 <0.001
AFP level at end of treatment >4.6 ng/mL 2.133 1.105–4.116 0.024

Other covariates were the age, presence of cirrhosis, platelet, alanine transaminase, γ-glutamyltransferase, and hyaluronic acid, albumin, AFP before therapy, and Fib-4 index.

HCC, hepatocellular carcinoma; 95% CI, 95% confidence interval; HCC, hepatocellular carcinoma; SVR, sustained virologic response; MRI, magnetic resonance imaging; CT, computed tomography; DAA, direct acting antivirals; AFP, alfa-fetoprotein

The comparison of the incidence of HCC between patients with or without hypovascular tumors and a history of HCC therapy who achieved an SVR

We compared the cumulative HCC development rates of patients with or without a hypovascular tumor and the history of HCC therapy. The patients were classified into four groups according to the presence of a hypovascular tumor and the history of HCC therapy, and the cumulative HCC development rates were examined in each group. The four groups were as follows: (a) no hypovascular tumor and no history of HCC therapy, (b) no hypovascular tumor and a history of HCC therapy, (c) a hypovascular tumor and no history of HCC therapy, and (d) a hypovascular tumor and a history of HCC therapy.

The cumulative HCC development rates at 1, 2, 3, and 4 years were as follows: group a = 0.6%, 2.8%, 3.8%, 4.8%; group b = 8.8%, 29.4%, 38.4%, 42.5%; group c = 26.7%, 33.3%, 50.6%, 73.7%; and group d = 41.7%, 66.7%, 83.3%, 91.7%, respectively (Fig 4A). Groups b, c, and d showed significantly higher cumulative HCC development rates than group a, and group d showed a significantly higher cumulative HCC development rate than group b (Fig 4A).

Fig 4. The comparison of the incidence of HCC between patients with or without hypovascular tumors and a history of HCC therapy who achieved SVR.

Fig 4

(a) Cumulative incidence rates of HCC among the four groups. (b) Cumulative incidence rates of HCC among the four groups in patients who underwent contrast-enhanced MRI or CT within two year before therapy or during DAA therapy. Group a, no hypovascular tumor and no history of HCC therapy; group b, no hypovascular tumor and a history of HCC therapy; group c, a hypovascular tumor and no history of HCC therapy; and group d, a hypovascular tumor and a history of HCC therapy.

Similarly, we analyzed patients who underwent CE-MRI or CT. The cumulative HCC development rates at 1, 2, 3, and 4 years were as follows: group a = 1.4%, 4.4%, 5.9%, 8.3%; group b = 10.3%, 34.5%, 41.4%, 45.9%; group c = 26.7%, 33.3%, 50.6%, 73.7%; and group d = 41.7%, 66.7%, 83.3%, 91.7%, respectively (Fig 4B). Groups b, c, and d showed significantly higher cumulative HCC development rates than group a, and group d showed a significantly higher cumulative HCC development rate than group b (Fig 4B).

Discussion

In the present study, we investigated the cumulative incidence rates of growth or hypervascularization of hypovascular tumors in 29 patients who were infected with HCV and treated by DAAs. The present study has novelty in the part that examined the detailed clinical course of hypovascular tumors. In patients who achieved an SVR, the cumulative incidence rates of growth or hypervascularization of hypovascular tumors were 19.4% at 1 year, 36.0% at 2 years, 56.6% at 3 years, and 65.3% at 4 years (Fig 3A). In previous studies, the cumulative incidence rates of hypervascularization were 14.9%-25% at 1 year and 45.8%-51% at 2 years [2022], especially, high-grade dysplastic nodule had high HCC development rates [14]. Toyoda et al. showed the rates of hypervascularization of hypovascular tumors did not differ markedly between the study patients who achieved an SVR and the propensity score-matched patients persistent HCV infection [23]. Compared with previous reports, the cumulative incidence rates of hypervascularization were not markedly different in the present study, although the background characteristics were different, including patients with etiologies other than HCV. In other words, DAAs cannot suppress the growth and hypervascularization of hypovascular tumors.

In addition, four patients had two hypovascular tumors each, and in two of these patients, one nodule showed hypervascularization, while the other nodule showed no change (Fig 2). It was considered that these two tumors in these patients had multicentric growth and a different carcinogenic potential in each tumor. In contrast, two patients developed small HCC in other lesions, but their hypovascular tumors showed no change (Fig 2). Of these two patients, one patient with a history of HCC therapy might have developed HCC due to intrahepatic metastasis. However, the other patient did not have any history of HCC. Therefore, the eradication of HCV by DAA therapy may not influence the hypervascularization of hypovascular tumors. However, there are some unclear points concerning the hypervascularization of hypovascular tumors, so the factors associated with the hypervascularization of hypovascular tumors will need to be clarified in a large study population in the future.

Several previous studies have shown the cumulative HCC developing rate in HCV-infected patients with hypovascular tumors who were treated with DAAs. Toyoda et al. showed that, among 164 patients with HCV cirrhosis who achieved an SVR by DAA therapy just before the start of therapy, 38 had non-hypervascular hypointense nodules (NHHNs) on EOB-MRI, and hypervascularization of NHHNs was observed in 17 patients (44.7%) [24]. Similarly, Ooka et al. showed that, in 864 patients with HCV infection across 2 cohorts, 41 patients developed HCC within 1 year after DAA therapy, and the factor associated with 1-year HCC occurrence and recurrence was the existence of a ‘‘dysplastic nodule” on imaging [25]. Marino et al. showed that, in 1,123 patients with cirrhosis who were treated with DAAs, 80 (7%) had non-characterized nodules, and the risk of HCC was significantly increased in patients with non-characterized nodules at baseline [26].

The common findings of the above reports were that patients with hypovascular tumors developed an early incidence of HCC. In the present study, the HCC development rates were higher in patients with hypovascular tumors than in those without any tumors and were similar to the rates in patients without any tumors who had a history of HCC therapy, although the background characteristics were different (Fig 4A and 4B). Furthermore, the patients with hypovascular tumors who had a history of HCC therapy had the highest incidence of HCC. Previous reports were observational studies conducted for one to two years after treatment, but the present study were observed for three to four years after DAA treatment. Since patients with hypovascular tumors have a high hepatocarcinogenetic potential, we should conduct periodic follow-up, such as tumor marker measurements and imaging, for a long time.

Recently, the elimination of HCV induced by DAA was shown to reduce the risk of HCC development and mortality in a large-scale observational study [10, 11, 27, 28]. In addition, the risk of HCC recurrence with DAA treatment is not markedly different from that with IFN treatment [12, 29, 30]. However, it has also been reported that DAA treatment may cause an unexpected onset of HCC [31, 32]. Although the mechanism underlying this unexpected onset of HCC has not been fully clarified, viral elimination by DAA treatment might reduce IFN-alfa-induced intrahepatic immunity, thus resulting in a rapid decrease in natural killer (NK) cell activity and the normalization of the NK cell cytotoxic effector function [33]. In addition, DAAs rapidly reduce inflammation but increase serum vascular endothelial growth factor (VEGF) levels [34], and the DAA-mediated increase in VEGF favors HCC recurrence/occurrence in susceptible patients with more severe fibrosis and splanchnic collateralization who already have abnormal activation in liver tissues of neo-angiogenetic pathways, like angiopoietin-2 [35]. Such immunological changes may be associated with a reduction in the immunosurveillance mechanism of neoplastic clones and an increase in VEGF and may thus promote hepatocarcinogenesis.

The present study was associated with several limitations. First, the number of study patients was small. Second, there were several missing values in the multivariate analysis, so the number of patients who were able to be examined was reduced. Third, various potentially influential factors (alcohol intake, obesity, etc.) were not examined after treatment. Fourth, 29 patients had hypovascular tumors that were confirmed by CE-MRI or CT. These surveys were conducted approximately 50 days before therapy. Further, 452 patients received DAA therapy after they were confirmed to be tumor-free by US, CT, or MRI. However, we did not confirm the exact US survey points before therapy. Thus, the start of the observation period was defined as the time at which DAA treatment was initiated. In addition, 168 patients without a hypovascular tumor underwent CE-MRI or CT within 2 years before therapy or during DAA therapy. Unfortunately, there were few patients who underwent CT or MRI immediately before DAA therapy. We cannot rule out the possibility of growth or hypervascularization of hypovascular tumors, or HCC development in patients who were tumor-free before DAA therapy. Thus, a future study should analyze a larger cohort which imaging surveillance was performed immediately before DAA therapy.

We concluded that hypovascular tumors developed into HCC at a high rate despite the elimination of HCV by DAAs. This suggests that DAAs cannot suppress the growth and hypervascularization of hypovascular tumors. As patients with hypovascular tumors tend to be older and frequently have liver cirrhosis along with a high risk of HCC development, they should undergo HCC surveillance carefully, similar to patients with a history of HCC therapy.

Supporting information

S1 Table. The baseline characteristics of patients and rate of HCC development for each survey method.

(DOCX)

S2 Table. Analysis data set.

All patients’ data sets were included in the following file.

(XLSX)

S3 Table. Analysis data set.

All data of hypovascular tumor data sets were included in the following file.

(XLSX)

Acknowledgments

The present study was carried out in the following 21 facilities (Kagoshima Liver Study Group): Kagoshima University Hospital, Kirishima Medical Center, Miyazaki Medical Center Hospital, Kagoshima Kouseiren Hospital, Kagoshima City Hospital, Saiseikai Sendai Hospital, Kohshinkai Ogura Hospital, Ikeda Hospital, Izumi General Medical Center, Oshima Hospital, Ibusuki Medical Center, Kagoshima medical center, Hirono Clinic, Kagoshima Teishin Hospital, Satsunan Hospital, Nagaki Clinic, Dr. NAKANISHI’s office, Southern Region Hospital, Tanegashima Medical Center, Fujimoto General Hospital, and Nakayama Clinic. We thank the following investigators: Shuzo Tashima (Kirishima Medical Center), Yasushi Imamura (Kagoshima Kouseiren Hospital), Toshihiro Fujita (Oshima Hospital), Akihiko Oshige (Ibusuki Medical Center), Shuichi Hirono (Hirono Clinic), Masahito Nagaki (Nagaki Clinic), Chihiro Nakanishi (Dr. NAKANISHI’s office), and Toshihiro nakayama (Nakayama Clinic). We also thank Ms. Hiromi Eguchi, Ms. Mayumi Ono, Ms. Etsuko Horiguchi, Ms. Yuko Morinaga, and Ms. Eriko Koreeda for their technical assistance and data management.

The study was presented as the previous draft in The International Liver Congress™ 2019 poster presentations.

Data Availability

All relevant data are within the paper and its Supporting Information files.

Funding Statement

This work was supported in part by a grant-in-aid from the Ministry of Health, Labour and Welfare of Japan (grant number: 18K15821) to SM and Bristol-Myers Squibb Co., Ltd to AI. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

References

  • 1.World Health Organization. Hepatitis C fact Sheet World Health Organization 2019 [cited 2020 April 4]. Available from: https://www.who.int/en/news-room/fact-sheets/detail/hepatitis-c.
  • 2.Villanueva A. Hepatocellular Carcinoma. N Engl J Med. 2019;380(15):1450–62. Epub 2019/04/11. 10.1056/NEJMra1713263 . [DOI] [PubMed] [Google Scholar]
  • 3.Kiyosawa K, Sodeyama T, Tanaka E, Gibo Y, Yoshizawa K, Nakano Y, et al. Interrelationship of blood transfusion, non-A, non-B hepatitis and hepatocellular carcinoma: analysis by detection of antibody to hepatitis C virus. Hepatology. 1990;12(4 Pt 1):671–5. Epub 1990/10/01. 10.1002/hep.1840120409 . [DOI] [PubMed] [Google Scholar]
  • 4.EASL Recommendations on Treatment of Hepatitis C 2018. J Hepatol. 2018;69(2):461–511. Epub 2018/04/14. 10.1016/j.jhep.2018.03.026 . [DOI] [PubMed] [Google Scholar]
  • 5.Hiramatsu N, Oze T, Takehara T. Suppression of hepatocellular carcinoma development in hepatitis C patients given interferon-based antiviral therapy. Hepatol Res. 2015;45(2):152–61. Epub 2014/07/24. 10.1111/hepr.12393 . [DOI] [PubMed] [Google Scholar]
  • 6.Morgan RL, Baack B, Smith BD, Yartel A, Pitasi M, Falck-Ytter Y. Eradication of hepatitis C virus infection and the development of hepatocellular carcinoma: a meta-analysis of observational studies. Annals of internal medicine. 2013;158(5 Pt 1):329–37. Epub 2013/03/06. 10.7326/0003-4819-158-5-201303050-00005 . [DOI] [PubMed] [Google Scholar]
  • 7.Ferrantini M, Capone I, Belardelli F. Interferon-alpha and cancer: mechanisms of action and new perspectives of clinical use. Biochimie. 2007;89(6–7):884–93. Epub 2007/05/29. 10.1016/j.biochi.2007.04.006 . [DOI] [PubMed] [Google Scholar]
  • 8.George PM, Badiger R, Alazawi W, Foster GR, Mitchell JA. Pharmacology and therapeutic potential of interferons. Pharmacol Ther. 2012;135(1):44–53. Epub 2012/04/10. 10.1016/j.pharmthera.2012.03.006 . [DOI] [PubMed] [Google Scholar]
  • 9.Innes H, Barclay ST, Hayes PC, Fraser A, Dillon JF, Stanley A, et al. The risk of hepatocellular carcinoma in cirrhotic patients with hepatitis C and sustained viral response: role of the treatment regimen. J Hepatol. 2017. Epub 2017/11/21. 10.1016/j.jhep.2017.10.033 . [DOI] [PubMed] [Google Scholar]
  • 10.Kanwal F, Kramer J, Asch SM, Chayanupatkul M, Cao Y, El-Serag HB. Risk of Hepatocellular Cancer in HCV Patients Treated With Direct-Acting Antiviral Agents. Gastroenterology. 2017;153(4):996–1005.e1. Epub 2017/06/24. 10.1053/j.gastro.2017.06.012 . [DOI] [PubMed] [Google Scholar]
  • 11.Ioannou GN, Green PK, Berry K. HCV eradication induced by direct-acting antiviral agents reduces the risk of hepatocellular carcinoma. Journal of Hepatology. 2018;68(1):25–32. 10.1016/j.jhep.2017.08.030. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 12.Nahon P, Layese R, Bourcier V, Cagnot C, Marcellin P, Guyader D, et al. Incidence of Hepatocellular Carcinoma After Direct Antiviral Therapy for HCV in Patients With Cirrhosis Included in Surveillance Programs. Gastroenterology. 2018;155(5):1436–50.e6. Epub 2018/07/22. 10.1053/j.gastro.2018.07.015 . [DOI] [PubMed] [Google Scholar]
  • 13.Takayama T, Makuuchi M, Hirohashi S, Sakamoto M, Okazaki N, Takayasu K, et al. Malignant transformation of adenomatous hyperplasia to hepatocellular carcinoma. Lancet. 1990;336(8724):1150–3. Epub 1990/11/10. 10.1016/0140-6736(90)92768-d . [DOI] [PubMed] [Google Scholar]
  • 14.Kobayashi M, Ikeda K, Hosaka T, Sezaki H, Someya T, Akuta N, et al. Dysplastic nodules frequently develop into hepatocellular carcinoma in patients with chronic viral hepatitis and cirrhosis. Cancer. 2006;106(3):636–47. Epub 2005/12/22. 10.1002/cncr.21607 . [DOI] [PubMed] [Google Scholar]
  • 15.Kokudo N, Hasegawa K, Akahane M, Igaki H, Izumi N, Ichida T, et al. Evidence-based Clinical Practice Guidelines for Hepatocellular Carcinoma: The Japan Society of Hepatology 2013 update (3rd JSH-HCC Guidelines). Hepatol Res. 2015;45(2). Epub 2015/01/28. 10.1111/hepr.12464 . [DOI] [PubMed] [Google Scholar]
  • 16.Sterling RK, Lissen E, Clumeck N, Sola R, Correa MC, Montaner J, et al. Development of a simple noninvasive index to predict significant fibrosis in patients with HIV/HCV coinfection. Hepatology. 2006;43(6):1317–25. Epub 2006/05/27. 10.1002/hep.21178 . [DOI] [PubMed] [Google Scholar]
  • 17.Mawatari S, Oda K, Tabu K, Ijuin S, Kumagai K, Inada Y, et al. New resistance-associated substitutions and failure of dual oral therapy with daclatasvir and asunaprevir. J Gastroenterol. 2017;52(7):855–67. Epub 2017/01/13. 10.1007/s00535-016-1303-0 . [DOI] [PubMed] [Google Scholar]
  • 18.Mawatari S, Oda K, Tabu K, Ijuin S, Kumagai K, Fujisaki K, et al. The co-existence of NS5A and NS5B resistance-associated substitutions is associated with virologic failure in Hepatitis C Virus genotype 1 patients treated with sofosbuvir and ledipasvir. PLoS One. 2018;13(6):e0198642 Epub 2018/06/02. 10.1371/journal.pone.0198642 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 19.Mawatari S, Oda K, Kumagai K, Tabu K, Ijuin S, Fujisaki K, et al. Viral and host factors are associated with retreatment failure in hepatitis C patients receiving all-oral direct antiviral therapy. Hepatol Res. 2020;50(4):453–65. Epub 2019/12/18. 10.1111/hepr.13474 . [DOI] [PubMed] [Google Scholar]
  • 20.Hyodo T, Murakami T, Imai Y, Okada M, Hori M, Kagawa Y, et al. Hypovascular nodules in patients with chronic liver disease: risk factors for development of hypervascular hepatocellular carcinoma. Radiology. 2013;266(2):480–90. Epub 2013/01/31. 10.1148/radiol.12112677 . [DOI] [PubMed] [Google Scholar]
  • 21.Inoue T, Hyodo T, Murakami T, Takayama Y, Nishie A, Higaki A, et al. Hypovascular hepatic nodules showing hypointense on the hepatobiliary-phase image of Gd-EOB-DTPA-enhanced MRI to develop a hypervascular hepatocellular carcinoma: a nationwide retrospective study on their natural course and risk factors. Digestive diseases (Basel, Switzerland). 2013;31(5–6):472–9. Epub 2013/11/28. 10.1159/000355248 . [DOI] [PubMed] [Google Scholar]
  • 22.Ogasawara S, Chiba T, Motoyama T, Kanogawa N, Saito T, Shinozaki Y, et al. Prognostic Significance of Concurrent Hypovascular and Hypervascular Nodules in Patients with Hepatocellular Carcinoma. PLoS One. 2016;11(9):e0163119 Epub 2016/09/21. 10.1371/journal.pone.0163119 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 23.Toyoda H, Kumada T, Tada T, Mizuno K, Sone Y, Akita T, et al. The impact of HCV eradication by direct-acting antivirals on the transition of precancerous hepatic nodules to HCC: A prospective observational study. Liver international: official journal of the International Association for the Study of the Liver. 2019;39(3):448–54. Epub 2018/10/13. 10.1111/liv.13987 . [DOI] [PubMed] [Google Scholar]
  • 24.Toyoda H, Kumada T, Tada T, Mizuno K, Sone Y, Kaneoka Y, et al. Impact of previously cured hepatocellular carcinoma (HCC) on new development of HCC after eradication of hepatitis C infection with non-interferon-based treatments. Alimentary pharmacology & therapeutics. 2018;48(6):664–70. Epub 2018/07/27. 10.1111/apt.14914 . [DOI] [PubMed] [Google Scholar]
  • 25.Ooka Y, Miho K, Shuntaro O, Nakamura M, Ogasawara S, Suzuki E, et al. Prediction of the very early occurrence of HCC right after DAA therapy for HCV infection. Hepatology international. 2018;12(6):523–30. Epub 2018/09/23. 10.1007/s12072-018-9895-5 . [DOI] [PubMed] [Google Scholar]
  • 26.Marino Z, Darnell A, Lens S, Sapena V, Diaz A, Belmonte E, et al. Time association between hepatitis C therapy and hepatocellular carcinoma emergence in cirrhosis: Relevance of non-characterized nodules. J Hepatol. 2019;70(5):874–84. Epub 2019/01/27. 10.1016/j.jhep.2019.01.005 . [DOI] [PubMed] [Google Scholar]
  • 27.Li DK, Ren Y, Fierer DS, Rutledge S, Shaikh OS, Lo Re V, 3rd, et al. The short-term incidence of hepatocellular carcinoma is not increased after hepatitis C treatment with direct-acting antivirals: An ERCHIVES study. Hepatology. 2018;67(6):2244–53. Epub 2017/12/06. 10.1002/hep.29707 . [DOI] [PubMed] [Google Scholar]
  • 28.Backus LI, Belperio PS, Shahoumian TA, Mole LA. Direct-acting antiviral sustained virologic response: Impact on mortality in patients without advanced liver disease. Hepatology. 2018;68(3):827–38. Epub 2018/01/30. 10.1002/hep.29811 . [DOI] [PubMed] [Google Scholar]
  • 29.Nagata H, Nakagawa M, Asahina Y, Sato A, Asano Y, Tsunoda T, et al. Effect of interferon-based and -free therapy on early occurrence and recurrence of hepatocellular carcinoma in chronic hepatitis C. J Hepatol. 2017;67(5):933–9. Epub 2017/06/20. 10.1016/j.jhep.2017.05.028 . [DOI] [PubMed] [Google Scholar]
  • 30.Nishibatake Kinoshita M, Minami T, Tateishi R, Wake T, Nakagomi R, Fujiwara N, et al. Impact of direct-acting antivirals on early recurrence of HCV-related HCC: Comparison with interferon-based therapy. J Hepatol. 2019;70(1):78–86. Epub 2018/10/20. 10.1016/j.jhep.2018.09.029 . [DOI] [PubMed] [Google Scholar]
  • 31.Reig M, Marino Z, Perello C, Inarrairaegui M, Ribeiro A, Lens S, et al. Unexpected high rate of early tumor recurrence in patients with HCV-related HCC undergoing interferon-free therapy. J Hepatol. 2016;65(4):719–26. Epub 2016/04/17. 10.1016/j.jhep.2016.04.008 . [DOI] [PubMed] [Google Scholar]
  • 32.Conti F, Buonfiglioli F, Scuteri A, Crespi C, Bolondi L, Caraceni P, et al. Early occurrence and recurrence of hepatocellular carcinoma in HCV-related cirrhosis treated with direct-acting antivirals. J Hepatol. 2016;65(4):727–33. Epub 2016/06/29. 10.1016/j.jhep.2016.06.015 . [DOI] [PubMed] [Google Scholar]
  • 33.Serti E, Chepa-Lotrea X, Kim YJ, Keane M, Fryzek N, Liang TJ, et al. Successful Interferon-Free Therapy of Chronic Hepatitis C Virus Infection Normalizes Natural Killer Cell Function. Gastroenterology. 2015;149(1):190–200.e2. Epub 2015/03/11. 10.1053/j.gastro.2015.03.004 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 34.Villani R, Facciorusso A, Bellanti F, Tamborra R, Piscazzi A, Landriscina M, et al. DAAs Rapidly Reduce Inflammation but Increase Serum VEGF Level: A Rationale for Tumor Risk during Anti-HCV Treatment. PLoS One. 2016;11(12):e0167934 Epub 2016/12/21. 10.1371/journal.pone.0167934 [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 35.Faillaci F, Marzi L, Critelli R, Milosa F, Schepis F, Turola E, et al. Liver Angiopoietin-2 Is a Key Predictor of De Novo or Recurrent Hepatocellular Cancer After Hepatitis C Virus Direct-Acting Antivirals. Hepatology. 2018;68(3):1010–24. Epub 2018/04/01. 10.1002/hep.29911 [DOI] [PMC free article] [PubMed] [Google Scholar]

Decision Letter 0

Tatsuo Kanda

17 Jun 2020

PONE-D-20-16242

Hypovascular tumors developed into hepatocellular carcinoma at a high rate despite the elimination of hepatitis C virus by direct-acting antivirals.

PLOS ONE

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Reviewers' comments:

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Comments to the Author

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Reviewer #1: Yes

Reviewer #2: Yes

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

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Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Is the manuscript presented in an intelligible fashion and written in standard English?

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Reviewer #1: Yes

Reviewer #2: Yes

**********

5. Review Comments to the Author

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Reviewer #1: Authors conclude hypovascular tuomrs developed into HCC at a high rate despite the elimination of HCV by DAAs. There are no major revisions required. Minor revisions required are as follows:

#1: It is recommended to give a definition of how many millimeter or more the growth of hypovascular tumors should be.

#2: The pixels in Figures are a little bit coarse.

Reviewer #2: This is a manuscript entitled “Hypovascular tumors developed into hepatocellular carcinoma at a high rate despite the elimination of hepatitis C virus by direct-acting antivirals

” by Kazuaki Tabu1, et al.

In this study, the authors analyzed whether DAAs can suppress the growth and hypervascularization of hypovascular tumors in prospective study. The authors showed that

of 33 hypovascular tumors, twenty of 33 nodules (60.6%) showed tumor growth or hypervascularization, and 13 (39.4%) nodules showed no change or improvement. The cumulative incidence rates of tumor growth or hypervascularization were 21.2% at 1 year, 36.8% at 2 years, and 55.9% at 3 years, and 69.9% at 4 years. And in patients with SVR, the cumulative HCC development rates of patients with hypovascular tumors was significantly higher than in

those without any tumors.

Although, this topic was analyzed by another groups, however, this study have several strength, including prospective study, and longer observation period.

This reviewer have some concerns to be address by the authors, as below

1. Please show whether the survey methods (CT/MRI vs echo) before treatment affect incidence of HCC or not,

, and please described when this survey was conducted (all patients were surveyed at initiation point of DAA?)

2 In Materials, and Method, Patients; the authors described that “ 168 without a hypovascular tumor underwent CE-MRI or CT within 2 year before therapy or during DAA therapy”

This reviewer think that 2 years is too long for diagnosis of no hypovascular tumor at baseline.

To avoid this, please limit the patients who were conducted CT around the point of initiation of DAAs, or to described this in limitation of this study.

3 In figure2, please show the analysis in patients who achieved SVR only.

**********

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Reviewer #1: Yes: Hidehiro Kamezaki

Reviewer #2: No

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PLoS One. 2020 Aug 13;15(8):e0237475. doi: 10.1371/journal.pone.0237475.r002

Author response to Decision Letter 0


10 Jul 2020

Thank you for your valuable feedback. We have revised the manuscript based on the comments.

Reviewer #1

1. It is recommended to give a definition of how many millimeter or more the growth of hypovascular tumors should be.

Thank you for your comments. HCC development was defined by 20% growth or hypervascularization of a hypovascular nodule. We have added this to the Materials and Methods section.

2. The pixels in Figures are a little bit coarse.

We have improved the resolution of the figure.

Reviewer #2:

1. Please show whether the survey methods (CT/MRI vs echo) before treatment affect incidence of HCC or not, and please described when this survey was conducted (all patients were surveyed at initiation point of DAA?)

The patients who underwent CT or MRI before DAA therapy had higher HCC development rates than those who underwent US alone. Because the patients who underwent CT or MRI more frequently had liver cirrhosis and a history of HCC therapy. We have created S1 Table and described the following in the Results section.

The patients who underwent CT or MRI before DAA therapy had higher rates of HCC development than those who underwent US alone. Because the patients who underwent CT or MRI more frequently had liver cirrhosis and a history of HCC therapy, had higher total bilirubin, GGT, hyaluronic acid, Fib-4 index, and AFP values before therapy and at the end of treatment, and had lower platelet counts and albumin levels than those who underwent US alone (S1 Table).

This study was a prospective observational study conducted in 29 patients with hypovascular tumors that were confirmed by CE-MRI or CT. Informed consent was obtained after the confirmation. Some of the patients applied for a medical subsidy program in Japan after giving their consent. Therefore, most patients were surveyed before DAA therapy. These surveys were conducted approximately 50 days before therapy.

We have described this in the Materials and Methods section. In addition, 452 patients received DAA therapy after they were confirmed to be tumor-free by US, CT, or MRI. However, we did not confirm the exact US survey points before therapy. Thus, the initiation of the observation period was defined as the initiation of DAA treatment. We have described this as a limitation of the present study.

2. In Materials, and Method, Patients; the authors described that “ 168 without a hypovascular tumor underwent CE-MRI or CT within 2 year before therapy or during DAA therapy”

This reviewer think that 2 years is too long for diagnosis of no hypovascular tumor at baseline. To avoid this, please limit the patients who were conducted CT around the point of initiation of DAAs, or to described this in limitation of this study.

Thank you for your comments. I agree with the reviewer's suggestions. Unfortunately, there were few patients who underwent CT or MRI immediately before DAA therapy. Since it overlaps with the comments in 1, we have described the following as a limitation of this study.

Fourth, 29 patients had hypovascular tumors that were confirmed by CE-MRI or CT. These surveys were conducted approximately 50 days before therapy. Further, 452 patients received DAA therapy after they were confirmed to be tumor-free by US, CT, or MRI. However, we did not confirm the exact US survey points before therapy. Thus, the start of the observation period was defined as the time at which DAA treatment was initiated. In addition, 168 patients without a hypovascular tumor underwent CE-MRI or CT within 2 years before therapy or during DAA therapy. Unfortunately, there were few patients who underwent CT or MRI immediately before DAA therapy. We cannot rule out the possibility of growth or hypervascularization of hypovascular tumors, or HCC development in patients who were tumor-free before DAA therapy. Thus, a future study should analyze a larger cohort which imaging surveillance was performed immediately before DAA therapy.

3. In figure2, please show the analysis in patients who achieved SVR only.

We have shown the analysis in patients who achieved an SVR only in Figure 2 and 3. We therefore corrected the data in the Abstract, Results and Discussion.

Attachment

Submitted filename: Response to Reviewers.docx

Decision Letter 1

Tatsuo Kanda

28 Jul 2020

Hypovascular tumors developed into hepatocellular carcinoma at a high rate despite the elimination of hepatitis C virus by direct-acting antivirals.

PONE-D-20-16242R1

Dear Dr. Seiichi Mawatari:

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Tatsuo Kanda, M.D., Ph.D.

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: All comments have been addressed

**********

2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: (No Response)

Reviewer #2: In this revise paper, the authors replied to my comments properly.

This study is worth reporting .

Thank you for giving me a chance to review this valuable article.

**********

7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

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Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: Yes: Hidehiro Kamezaki

Reviewer #2: No

Acceptance letter

Tatsuo Kanda

3 Aug 2020

PONE-D-20-16242R1

Hypovascular tumors developed into hepatocellular carcinoma at a high rate despite the elimination of hepatitis C virus by direct-acting antivirals.

Dear Dr. Mawatari:

I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

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Associated Data

    This section collects any data citations, data availability statements, or supplementary materials included in this article.

    Supplementary Materials

    S1 Table. The baseline characteristics of patients and rate of HCC development for each survey method.

    (DOCX)

    S2 Table. Analysis data set.

    All patients’ data sets were included in the following file.

    (XLSX)

    S3 Table. Analysis data set.

    All data of hypovascular tumor data sets were included in the following file.

    (XLSX)

    Attachment

    Submitted filename: Response to Reviewers.docx

    Data Availability Statement

    All relevant data are within the paper and its Supporting Information files.


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