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. 2020 Sep 3;15(9):e0238392. doi: 10.1371/journal.pone.0238392

Efficacy of surgical management for recurrent intrahepatic cholangiocarcinoma: A multi-institutional study by the Okayama Study Group of HBP surgery

Toru Kojima 1,#, Yuzo Umeda 2,*,#, Tomokazu Fuji 1, Takefumi Niguma 1, Daisuke Sato 3, Yoshikatsu Endo 4, Kenta Sui 5, Masaru Inagaki 6, Masahiro Oishi 7, Tetsuya Ota 8, Katsuyoshi Hioki 9, Tadakazu Matsuda 10, Hideki Aoki 11, Ryuji Hirai 12, Masashi Kimura 13, Takahito Yagi 2, Toshiyoshi Fujiwara 2
Editor: Gianfranco D Alpini14
PMCID: PMC7470360  PMID: 32881910

Abstract

Background

The prognosis of intrahepatic cholangiocarcinoma (ICC) has been poor, because of the high recurrence rate even after curative surgery. This study aimed to evaluate the prognostic impact of surgical resection of recurrent ICC.

Patients and methods

A total of 345 cases of ICC who underwent hepatectomy with curative intent in 17 institutions were retrospectively analyzed, focusing on recurrence patterns and treatment modalities for recurrent ICC.

Results

Median survival time and overall 5-year recurrence-free survival rate were 17.8 months and 28.5%, respectively. Recurrences (n = 223) were classified as early (recurrence at ≤1 year, n = 131) or late (recurrence at >1 year, n = 92). Median survival time was poorer for early recurrence (16.3 months) than for late recurrence (47.7 months, p<0.0001). Treatment modalities for recurrence comprised surgical resection (n = 28), non-surgical treatment (n = 134), and best supportive care (BSC) (n = 61). Median and overall 1-/5-year survival rates after recurrence were 39.5 months and 84.6%/36.3% for surgical resection, 14.3 months and 62.5%/2.9% for non-surgical treatment, and 3 months and 4.8%/0% for BSC, respectively (p<0.0001). Multivariate analysis identified early recurrence, simultaneous intra- and extrahepatic recurrence, and surgical resection of recurrence as significant prognostic factors. In subgroup analyses, surgical resection may have positive prognostic impacts on intra- and extrahepatic recurrences, and even on early recurrence. However, simultaneous intra- and extrahepatic recurrence may not see any survival benefit from surgical management.

Conclusion

Surgical resection of recurrent ICC could improve survival after recurrence, especially for patients with intra- or extrahepatic recurrence as resectable oligo-metastases.

Introduction

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary malignant tumor of the liver, accounting for 10–20% of all primary liver malignancies [1]. Surgery has been regarded as a potentially curative treatment, providing ICC patients with a median overall survival (OS) of 14.4–38.8 months [24]. Unfortunately, many cases are diagnosed at an advanced stage, because ICC shows few specific early symptoms. Only about 20–40% of potentially operable patients are offered operative resection [5]. On the other hand, several reports have described the efficacy of systemic chemotherapy. While various regimens can achieve partial response, the effects seem limited [68].

Recurrence after curative surgery for ICC is common, with a reported recurrence rate of 50–79% [2, 4, 9, 10]. Many and various clinical factors have been identified as risk factors for recurrence and poor survival [1115]. As with hepatocellular carcinoma (HCC), ICC shows a metastatic predilection for the liver, so locoregional therapy may represent a reasonable approach [16]. Ercolani et al. reported that aggressive multimodal treatment of recurrent ICC is associated with better outcomes [15]. A multi-institutional study showed that re-resection contributed to relatively better prognosis than systemic chemotherapy or best supportive care (BSC) [10]. A steadily improving understanding of risk factors for ICC recurrence and improved postoperative monitoring with modern imaging modalities is increasingly permitting diagnosis of recurrent ICC at an early stage while repeat resection is still technically feasible [5]. Considering these circumstances, re-evaluation of the efficacy of surgery for ICC recurrence appears worthwhile.

The aim of this study was to evaluate the prognostic impact of surgical resection for recurrent ICC, with a particular focus on the timing and patterns of recurrence.

Materials and methods

Study subjects

Participants in the present multicenter, retrospective comprised 404 adult subjects who had undergone hepatic resection with curative intent between January 2000 and December 2016. Clinical data for these subjects were collected from 17 medical institutions (Okayama University Hospital, Okayama Saiseikai General Hospital, Hiroshima Citizens Hospital, Kochi Health Sciences Center, Himeji Red Cross Hospital, National Fukuyama Medical Center, Tottori Municipal Hospital, Tenwakai Matsuda Hospital, National Okayama Medical Center, Fukuyama City Hospital, Himeji St. Maria Hospital, Matsuyama Municipal Hospital, Sumitomo Besshi Hospital, Onomichi Municipal Hospital, National Iwakuni Medical Center, Himeji Central Hospital, and Kobe Red Cross Hospital). Of these, 12 institutions are board-certified training institutions for the Hepatobiliary and Pancreatic Surgery program in Japan [17]. Consequently, most patients were recruited from high-volume centers, leading to relatively standardized operative procedures and outcomes. Subjects meeting any of the following criteria were excluded: 1) insufficient clinical records (n = 35); 2) surgery-related death (n = 17); or 3) lack of follow-up data (n = 7). The definition of surgery-related death was mortality due to surgical complications within 90 days after surgery. On the other hand, comparatively early deaths due to recurrent tumor progression were not excluded. After excluding those individuals who met the exclusion criteria, a total of 345 subjects were included in this study.

The following demographic and clinical data were reviewed through medical records: age; sex; body mass index (BMI); history of diabetes mellitus; serum levels of carbohydrate antigen (CA)19-9 and carcinoembryonic antigen (CEA); maximum tumor diameter; number, localization, and morphology of tumors; surgical procedure; histological grade; vascular/serosal invasion; and timing and patterns of recurrence. With regard to localization of primary ICC, all ICCs were classified as hilar or peripheral type based on the anatomical origin of the tumor. The anatomical location of the tumor was judged from preoperative imaging such as computed tomography (CT) or magnetic resonance imaging (MRI). Tumors with the intrahepatic component and involvement of a large bile duct comparable with the intrahepatic second or third branches were defined as hilar type, whereas the other tumors involved in smaller than segmental branches were defined as peripheral type ICC.

Follow-up protocol and diagnosis of recurrence

Patients with lymph node metastasis and/or positive surgical margins received adjuvant chemotherapy with regimens comprising gemcitabine and cisplatin or oral fluorinated pyrimidine for 6 months. After initial surgery, all patients were regularly followed-up every 3 months for the first 2 years, and every 6 months thereafter. At each visit, in addition to basic blood examinations, serum CA19-9 and CEA levels, contrast-enhanced chest and abdominal CT, and/or abdominal MRI were examined. Positron emission tomography (PET) was added in patients showing suspected subclinical recurrence or extrahepatic metastasis on CT or MRI. Diagnosis of recurrence was mainly based on these radiological findings with or without elevated concentrations of CA19-9. For cases without these definitive findings, diagnosis required endoscopic or percutaneous biopsy. Recurrence at ≤1 year postoperatively was defined as early recurrence, as reported previously [18]. Recurrence at >1 year was thus defined as late recurrence.

Treatment modalities for recurrence and decision of them

Treatment strategy for each case of recurrence was assessed by a multidisciplinary team comprising liver surgeons, oncologists, hepatologists, and radiologists. Surgical resection for the recurrent site could be indicated, according to technical resectability, such as solitary or oligo-metastasis and patient conditions including performance status, estimated volume of future liver remnant, and feasibility and tolerability of repeat surgery. Of course, complete resection as R0 was required as the intent of repeat surgery. Patients who did not meet these criteria were treated by chemotherapy and/or radiation therapy as non-surgical treatment, or by BSC.

Statistical analysis

Clinical variables were compared using the Mann-Whitney U test for continuous data and the Pearson’s correlation coefficient for categorical data. Continuous variables are presented as median and interquartile range (IQR). Values of p<0.05 were considered significant. OS was evaluated using the Kaplan-Meier method and compared using log-rank testing. Cox’s proportional hazard model was used to identify prognostic factors for recurrent cases. For this analysis, clinical variables showing values of p<0.10 in univariate analyses were entered into multivariate analysis. Hazard ratios (HRs) and 95% confidence intervals (95%CIs) were calculated. All statistical analyses were performed using JMP version 14 (SAS Institute Inc., Cary, NC, USA)).

Ethics statement

This study conformed to the Declaration of Helsinki on Human Research Ethics standards and was approved by the Okayama University Hospital Institutional Ethics Board (number 1701–026). Since this study was retrospective in nature, there was no written informed consent from the investigated patients. All data were blinded before analysis.

Results

Demographic characteristics of patients are provided in Table 1, and patient flow is summarized in Fig 1. The predominant tumor morphology was the mass-forming type (n = 256), followed by the periductal infiltrating type (n = 77), and intraductal growth type (n = 12). With regard to surgical procedures, more than 70% of patients underwent right/left hemi-hepatectomy or trisectionectomy as major hepatectomy, due to tumor extension. Most patients with tumor adjacent to the biliary confluence, such as hilar-type ICC, underwent bile duct resection. In our cohort, therapeutic lymph node dissection (LND) was performed for 235 patients (68%), of whom 96 patients showed positive lymph node metastasis on final histopathological examination; the rate of lymph node metastasis was 41%. The rate of positive surgical margins (including bile duct or liver cut surface) was 16%. Patients showing lymph node metastasis and/or positive surgical margins received adjuvant chemotherapy for 6 months.

Table 1.

Variables All (n = 345) Recurrence (n = 223) No Recurrence (n = 122) P-value***
Parameters at initial resection
Sex: Male / Female (%) 214 (62%) / 131 (38%) 138 (62%) / 85 (38%) 76 (62%) / 46 (38%) 0.94
Age * 70 (63–76) 70 (63–76) 69 (64–77) 0.579
BMI * 22 (20–24.8) 22 (19.9–24.5) 22.2 (20.1–25.9) 0.174
Diabetes mellitus (%) 66 (20%) 41 (18%) 25 (21%) 0.634
Tumor factors
CEA (ng/ml) * 2.9 (1.8–5.8) 2.9 (1.8–6.1) 2.8 (1.8–9.9) 0.394
CA19-9 (U/ml) * 39.8 (14.7–212) 56.2 (16–456) 27 (12.6–87.7) 0.004
Maximum tumor diameter (cm) * 4.3 (2.8–6.7) 4.8 (3.1–7) 3.3 (2.4–5) <0.0001
Morphology
Mass forming / Periductal infiltrating / Intraductal growth (%) 256 (74%) / 77 (22%) / 12 (4%) 164 (74%) / 55 (25%) / 4 (2%) 92 (75%) / 22 (18%) / 8 (7%) 0.035
Solitary / Multiple lesion (%) 275 (80%) / 70 (20%) 166 (74%) / 57 (26%) 109 (89%) / 13 (11%) 0.001
Hilar type / Peripheral type (%) 125 (36%) / 220 (64%) 94 (42%) / 129 (58%) 31 (25%) / 91 (75%) 0.002
Treatment factors
Major hepatectomy / Minor hepatectomy (%) 247 (72%) / 98 (28%) 170 (76%) / 53 (24%) 77 (63%) / 45 (37%) 0.009
Lymph node dissection (%) 235 (68%) 161 (72%) 74 (61%) 0.027
Bile duct resection (%) 100 (29%) 77 (35%) 23 (19%) 0.002
Vascular reconstruction (%) 26 (7.5%) 21 (9%) 5 (4%) 0.073
Adjuvant Chemotherapy (%) 123 (35%) 93 (42%) 30 (25%) 0.002
Pathological factors
Microscopic surgical margin positive (%) 56 (16%) 45 (20%) 11 (9%) 0.007
Lymph node metastasis (%) ** 96 (41%) 79 (48%) 17 (23%) 0.0004
Serosa invasion (%) 139 (40%) 111 (49%) 28 (23%) <0.0001
Vascular invasion (%) 219 (63%) 165 (74%) 54 (44%) <0.0001
fibrosis (%) 90 (26%) 52 (23%) 38 (31%) 0.113
Poorly/undifferentiated (%) 71 (21%) 54 (24%) 17 (14%) 0.023

* Median and IQR: interquartile range,

** Among cases with lymph node dissection,

*** Recurrence vs No Recurrence.

Fig 1. Inclusion and exclusion criteria applied in the present study.

Fig 1

A total of 223 patients showed recurrent ICC, with a median recurrence-free survival (RFS) of 17.8 months. Univariate analysis indicated the following significant risk factors for recurrence: preoperative CA19-9; maximum tumor diameter; periductal infiltrating type as the morphological type; multiple nodules; hilar-type ICC; requirement of major hepatectomy; LND; bile duct resection; vascular reconstruction; adjuvant chemotherapy; positive results for microscopic surgical margins; serosal invasion; positive lymph nodes; vascular invasion; and poorly/undifferentiated tumor (Table 1).

Patients with recurrence were divided into two groups according to the time to recurrence (TTR): early recurrence, ≤1 year after surgery (n = 131); and late recurrence, >1 year after surgery (n = 92). From other perspectives, pattern of recurrence was classified as intrahepatic only (n = 79); extrahepatic only (n = 109); or simultaneous intra- and extrahepatic recurrence (n = 35) (Fig 2a). The most frequent site of extrahepatic metastasis was lung (n = 49), followed by pleura/peritoneum including local recurrence (n = 42), lymph node (n = 40), bone (n = 11), and adrenal grand (n = 2) (Fig 2b). Treatment modalities for these recurrences comprised surgical resection (n = 28), non-surgical treatment (n = 134), and BSC (n = 61). Rates of surgical resection were high for intrahepatic-only recurrence and late recurrence. Surgical resection of recurrent sites comprised repeat hepatectomy for intrahepatic recurrence (n = 14) and local recurrence (n = 1), lung resection (n = 6), LND (n = 3), resection of local recurrence with bile duct (n = 1), adrenectomy (n = 1), and partial resection of abdominal wall (n = 1). On the other hand, non-surgical treatment comprised systemic chemotherapy alone (n = 113), radiation (n = 10), chemo-radiation (n = 6), and radiofrequency ablation (n = 5). Clinical backgrounds of all recurrent cases according to treatment modalities are summarized in Table 2. In view of higher concentrations of preoperative CA19-9 and rates of lymph node metastasis, serosal invasion, and requirement of major hepatectomy, initially advanced ICC was significantly associated with non-surgical treatment or BSC. On the other hand, the group of patients who underwent surgical resection showed the highest induction rate of adjuvant chemotherapy (50%), followed by 48% for patients with non-surgical treatment, and 24% for patients receiving only BSC (p = 0.006). In terms of timing and pattern of recurrence, early recurrences were less likely to receive intervention by surgical resection, compared with late recurrence (p = 0.028). That is, early recurrences were treated using other modalities (p = 0.028) (Fig 3). Intrahepatic- or extrahepatic-only metastasis in late recurrence could be selected for surgical resection: resection rates were 31% for intrahepatic recurrence alone, and 13% in extrahepatic recurrence alone. However, only 10% of simultaneous intra- and extrahepatic recurrences met the indications for surgical resection (Fig 1).

Fig 2. Recurrent pattern (a) and sites of extrahepatic recurrence (b).

Fig 2

Table 2.

Variables Surgical resection (n = 28) Non-Surgical resection (n = 134) BSC (n = 61) P-value
Parameters at initial resection
Sex: Male / Female (%) 16 (57%) / 12 (43%) 82 (61%) / 52 (39%) 40 (66%) / 21 (34%) 0.724
Age * 71 (62–75) 69 (62–75) 72 (64–78) 0.244
BMI * 23.4 (18.7–25) 21.9 (20–24) 22.7 (20.4–24.8) 0.525
Diabetes mellitus (%) 5 (18%) 28 (21%) 8 (17%) 0.794
Tumor factors
CEA (ng/ml) * 2.9 (1.5–4.3) 2.8 (1.7–5.9) 4.6 (2.1–10.1) 0.053
CA19-9 (U/ml) * 18.3 (11–41) 65 (16–439) 146 (21.9–2030) 0.004
Maximum tumor diameter (cm) * 4.9 (3.9–8) 4.8 (3–7.2) 4.8 (3–8.9) 0.582
Morphology
Mass forming / Periductal infiltrating / Intraductal growth (%) 23 (82%) / 3 (11%) / 2 (7%) 100 (75%) / 33 (25%) / 1 (0.5%) 41 (67%) / 19 (31%) / 1 (1.5%) 0.056
Solitary / Multiple lesion (%) 21 (75%) / 7 (25%) 100 (75%) / 34 (25%) 45 (74%) / 16 (26%) 0.989
Hilar type / Peripheral type (%) 6 (21%) / 22 (79%) 61 (45%) / 73 (54%) 27 (44%) / 34 (56%) 0.058
Treatment factors
Major hepatectomy / Minor hepatectomy (%) 18 (64%) / 10 (36%) 99 (74%) / 35 (26%) 53 (87%) / 8 (13%) 0.04
Lymph node dissection (%) 17 (60%) 101 (75%) 43 (70%) 0.272
Bile duct resection (%) 7 (25%) 47 (35%) 23 (37%) 0.493
Vascular reconstruction (%) 2 (7%) 12 (9%) 7 (11%) 0.776
Adjuvant Chemotherapy (%) 14 (50%) 64 (48%) 15 (24%) 0.006
Pathological factors
Microscopic surgical margin positive (%) 7 (25%) 27 (20%) 11 (18%) 0.748
Lymph node metastasis (%)** 6 (35%) 43 (41%) 30 (65%) 0.016
Serosa invasion (%) 10 (35%) 62 (46%) 39 (64%) 0.021
Vascular invasion (%) 19 (68%) 102 (76%) 44 (72%) 0.614
fibrosis (%) 6 (21%) 33 (25%) 12 (21%) 0.851
Poorly/undifferentiated (%) 8 (29%) 30 (22%) 16 (26%) 0.716
Parameters at recurrence
Timing of recurrence 0.028
Early Recurrence (≤ 1-year) 10 (35%) 82 (61%) 39 (64%)
Late Recurrence (>1-year) 18 (64%) 52 (38%) 22 (36%)
Site of recurrence 0.198
Intrahepatic only 14 (50%) 50 (37%) 15 (25%)
Extrahepatic only 11 (39%) 63 (47%) 35 (57%)
Simultaneous Intra- & Extrahepatic 3 (11%) 21 (16%) 11 (18%)

* Median and IQR: interquartile range,

** Among cases with lymph node dissection.

Fig 3. Correlations between treatment modalities and sites (a) and timing (b) of recurrence.

Fig 3

In survival analysis, 5-year RFS rate and median survival time (MST) were 28.5% and 17.8 months, respectively. Five-year OS rate and MST were 40.9% and 42.3 months, respectively (S1 Fig). MST and 1-/5-year OS after initial surgery were 140.6 months and 98.2%/89.2% in the no-recurrence group, 16.3 months and 61.5%/4.2% in the early recurrence group, and 47.7 months and 98.9%/37.9% in the late recurrence group, respectively (p<0.0001) (Fig 4a). As for survival after recurrence, simultaneous intra- and extrahepatic recurrence showed the shortest survival time, compared with extrahepatic-only and intrahepatic-only metastasis: MSTs were 9.4 months for simultaneous intra- and extrahepatic recurrence, 10.7 months for extrahepatic-only recurrence, and 18.6 months for intrahepatic-only recurrence, respectively (p = 0.056) (Fig 4b). Regarding treatment modalities, surgical resection showed longer survival after recurrence (MST, 39.5 months) than non-surgical treatment (14.3 months; p<0.0001) or BSC (3.0 months; p<0.0001) (Fig 5a). In sub-group analysis according to recurrence pattern, survival benefit from surgical resection of the recurrent lesion was not recognized in patients with simultaneous intra- and extrahepatic metastasis, but was seen in intrahepatic- or extrahepatic-only metastasis (Fig 5b–5d). Furthermore, in the 223 cases with recurrence, Cox’s proportional hazard modeling identified early recurrence (HR 1.39, p = 0.046), simultaneous intra- and extrahepatic metastases compared with intrahepatic-only recurrence (HR 1.65, p = 0.043), and surgical resection of recurrence compared with BSC (HR 0.06, p<0.001) or non-surgical treatment (HR 0.46, p = 0.007) as independent prognostic factors for post-recurrence survival. In contrast, among factors at initial surgery, only hilar-type ICC (HR 1.60, p = 0.005) was selected as a significant factor (Table 3). Regardless of the timing of relapse, the superiority of surgical resection over other treatment modalities was evident (p<0.0001) (Fig 6a and 6b). Particularly in late recurrence, surgical resection resulted in long-term survival almost equivalent to that seen in no-recurrence cases.

Fig 4. Overall survival after primary resection, stratified by recurrence timing (a) and recurrence pattern (b).

Fig 4

Fig 5. Survival curves after recurrence stratified by treatment modalities in all patients with recurrence (a), intrahepatic-only recurrence (b), extrahepatic-only recurrence (c), and simultaneous intra- and extrahepatic recurrence (d).

Fig 5

Table 3.

Univariate Analysis Multivariate Analysis
Variables Hazards ratio 95% C.I. P-value Hazards ratio 95% C.I. P-value
Parameters at initial resection
Sex: Male vs Female 1.220 0.927–1.608 0.154
Age 1.021 1.005–1.037 0.010 1.014 0.995–1.033 0.127
BMI 1.012 0.974–1.052 0.520
Diabetes mellitus + vs - 0.859 0.605–1.220 0.396
Tumor factors
CEA (ng/ml) 1.001 0.999–1.002 0.152
CA19-9 (U/ml) 1.000 0.999–1.000 0.120
Maximum tumor diameter (cm) 0.992 0.942–1.043 0.766
Macroscopic type
 Mass forming type vs Periductal infiltrating type 0.804 0.577–1.140 0.216
 Mass forming type vs Intra-ductal growth type 1.414 0.594–4.616 0.471
 Periductal infiltrating type vs Intra-ductal growth type 1.759 0.712–5.846 0.242
Multiple lesions vs Solitary lesion 1.096 0.809–1.485 0.551
Hilar type vs Peripheral type 1.440 1.095–1.895 0.009 1.602 1.154–2.223 0.005
Treatment factors
Major hepatectomy vs Minor hepatectomy 1.183 0.859–1.629 0.300
Lymph node dissection + vs - 0.977 0.723–1.321 0.881
Bile duct resection + vs - 1.241 0.942–1.648 0.122
Vascular reconstruction + vs - 1.043 0.663–1.642 0.853
Adjuvant Chemotherapy vs no-Adjuvant Chemotherapy 0.999 0.761–1.310 0.994
Pathological factors
Microscopic surgical margin positive vs negative 1.103 0.793–1.534 0.558
Lymph node metastasis + vs - 1.363 1.001–1.858 0.048 1.032 0.741–1.437 0.850
Serosa invasion + vs - 1.193 0.913–1.559 0.196
Vascular invasion + vs - 1.129 0.831–1.531 0.435
fibrosis + vs - 1.059 0.771–1.458 0.720
Poorly/undifferentiated vs Well/mod. differentiated 1.001 0.737–1.373 0.970
Parameters at recurrence
Early Recurrence (≤ 1-year) vs. Late recurrence (>1-year) 1.501 1.145–1.981 0.003 1.398 1.005–1.946 0.046
Recurrence site
 Simultaneous intra- & extrahepatic vs. Intrahepatic only 1.719 1.143–2.589 0.009 1.646 1.015–2.671 0.043
 Simultaneous intra- & extrahepatic vs. Extrahepatic only 1.278 0.864–1.879 0.220 1.387 0.880–2.184 0.157
 Extrahepatic only vs. Intrahepatic only 1.348 1.003–1.813 0.048 1.187 0.835–1.687 0.339
Treatment for recurrence
 Surgical resection vs BSC 0.063 0.037–0.110 <0.001 0.059 0.029–0.118 <0.001
 Surgical resection vs Non-surgical treatment 0.439 0.287–0.684 <0.0003 0.463 0.264–0.809 0.007
 Non-surgical treatment vs BSC 0.145 0.100–0.210 <0.001 0.128 0.082–0.200 <0.001

Fig 6. Overall survival after primary resection by treatment modality, compared with no-recurrence patients, in early recurrence (≤1 year; a) and late recurrence (>1 year; b).

Fig 6

Discussion

In this study, 5-year overall RFS and MST were 28.5% and 17.8 months, respectively. In previous reports focusing on postoperative recurrence of ICC, median RFS has been reported as 11–17 months [5, 1923]. Similar to those reports, our cohort showed recurrence approximately 1.5 year after initial surgery. Long-term recurrence and survival outcomes remain disappointing. Risk factors for recurrence after initial surgery are reported to include increased age, larger tumor diameter, macrovascular invasion, cirrhosis of the underlying liver, lymph node metastasis, and presence of multifocal disease. These are considered to be risk factors for both recurrence and poor survival [1114]. Many reports have mentioned LND for ICC. The value of routine LND for ICC remains controversial [2426]. Routine LND can facilitate accurate staging with precise identification of nodal status, and can predict indication for adjuvant therapy [27]. Given these valuable aspects, LND of regional nodes may be considered as a standard option [28]. Adjuvant chemotherapy was unable to improve prognosis for all ICC patients after surgical resection, but could provide a potential survival benefit in subgroups of patients exhibiting increased risk, such as advanced tumors or positive lymph node metastasis [29, 30]. In our patient cohort, approximately 70% of patients showed positive nodal status. Interestingly, the induction rate of adjuvant chemotherapy was higher in the group with surgical resection than in those with non-surgical treatment or BSC (p = 0.004). Perhaps this data suggested that adjuvant chemotherapy could increase the resection rate via control of cancer spread, leading to oligo-metastasis.

The rate of surgical resection seems to correlate with the timing and type of recurrence. In other words, this could be affected by the spread of cancer. Preoperative levels of CA19-9 in non-surgical treatment and BSC were thus higher than that with surgical resection. Of course, taking into account high rates of lymph node metastasis, serosal invasion, and requirement for major hepatectomy, initial advanced tumor would result in aggressive recurrence treated by non-surgical treatment or BSC, instead of surgical resection. In addition, preoperative CA19-9 could offer a promising predictive biomarker implying subclinical cancer spread at initial surgery.

No clear treatment guideline is currently available for recurrence, especially for patients with localized or systemic intrahepatic ICC recurrence. Several studies have evaluated the impact of various treatments, such as repeat hepatectomy, radiofrequency ablation, chemotherapy or radiotherapy on survival following recurrence of ICC [5, 15, 16, 1922]. Although each report has shown the limitation of being a retrospective analysis, surgical resection of the site of recurrence was clearly established as an effective therapeutic option. In those reports, median post-recurrence survival after surgical resection was reported as 20–45 months. In this study, surgical resection of recurrent lesions showed 39.5 months as the MST and 84.6% and 36.3% as the 1- and 5-year OS rates after recurrence, significantly better than those from non-surgical treatment and BSC. Surgical resection can obviously provide clear survival benefits to patients with intrahepatic-only or extrahepatic-only recurrence. Conversely, surgical treatment may not be appropriate for simultaneous intra- and extrahepatic recurrence. Compared with previous reports, our study showed that post-recurrence survival seemed slightly better after surgical resection. However, these differences would be derived just from patient selection for surgical resection; in our patient cohort, the indication of surgical resection for recurrent ICC was limited to cases with the prospect of R0. Even though surgical resection is the best treatment modality for recurrent ICC, non-curative repeat surgery could end up providing outcomes just as dismal as those from non-surgical treatment [23]. This efficacious treatment option thus should not be adopted for ‘debulking’ effects, but under a radical “cleaning-up” policy for R0.

With regard to tumor localization, hilar type ICC was indicated as one of significant prognostic factors. The pathological background and gross and histological features of ICCs are reported to differ according to the anatomical site [31, 32]. The hilar type ICCs originated from intrahepatic large biliary ducts are likely to show aggressive course with metastatic potential. Though tumor localization could be classified according to radiological findings in this study, classification based on radiological findings has been reported to accurately reflect histomorphological typing [33, 34]. In fact, hilar type ICC, defined by radiological localization in this study, showed higher recurrence rate and poorer survival than peripheral type. The low resection rate for recurrence in primary major hepatectomy cases and hilar type ICCs may be due to the grade of hilar type ICCs as well as the reduced liver reserve caused by the initial surgery, which may influence the decision to treat patients at the time of recurrence and the post-recurrent survival.

TTR has been reported as a crucial factor to predict prognosis after recurrence [5]. This interval is closely associated with tumor biology, including the metastatic potential of intra- or extrahepatic metastasis. In HCC, optimal cut-off values for differentiating between early and late tumor recurrence remain controversial [35]. Few studies have explored the issue in ICC, but TTR ≤ 1 year has been proposed as a valuable cut-off for early recurrence of ICC [18, 36]. According to those reports, we classified two groups to differentiate early and late recurrence. This cut-off was likely adequate, allowing could clear differentiation of survival both after initial surgery and after recurrence. Notably, surgical resection of recurrent ICC could show a positive prognostic impact even for early recurrence. Based on previous reports, surgical intervention for early recurrence showed poorer prognosis than that for late recurrence [5]. On the other hand, another report found that early recurrence did not affect post-recurrence survival [22]. Thus, regardless of TTR, surgical resection exerts a positive prognostic effect on survival after initial surgery or recurrence. However, in early recurrence, only patients with biologically low-grade recurrences or limited recurrent disease could benefit from surgical resection. In other words, the power of surgical resection relies heavily on the degree of recurrent-tumor distribution. Judging whether recurrent tumor represents limited disease is thus essential.

Conclusions

Even if recurrences seem resectable, careful follow-up with chemotherapy may be advisable to determine biological malignancy. On the other hand, surgical resection for late-phase recurrence could provide a curative option offering equivalent prognosis to that of no-recurrence cases. While surgery remains the only way to obtain radical cure in ICC, surgery alone cannot achieve cure. Considering treatment strategies for ICC, initial surgery is only the first step and the introduction of adjuvant chemotherapy based on accurate staging should follow. In cases with recurrence, the path of surgical resection should always be explored to improve prognosis.

Supporting information

S1 Fig. Overall and recurrence-free survival curves.

(TIFF)

Acknowledgments

The authors thank their colleagues who contributed to data collection for this study: Kazuyasu KOBAYASHI (Sumitomo Besshi Hospital), Toshihiro MURATA (Onomichi Municipal Hospital), Yasuhiko ISHIDA (Himeji Central Hospital), and Nobuhiro ISHIDO (Kobe Red Cross Hospital).

Data Availability

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

Funding Statement

Financial support was received from the Japan Society for the Promotion of Science (grant number 19K09217 to Yuzo UMEDA).

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Decision Letter 0

Gianfranco D Alpini

17 Jul 2020

PONE-D-20-19960

Efficacy of surgical management for recurrent intrahepatic cholangiocarcinoma: A multi-institutional study by the Okayama study group of HBP surgery

PLOS ONE

Dear Dr. Yuzo Umeda,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.  The Editorial team found merit in your study and we encourage a resubmission.

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Academic Editor

PLOS ONE

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[Note: HTML markup is below. Please do not edit.]

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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

Reviewer #3: Partly

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

Reviewer #1: Yes

Reviewer #2: I Don't Know

Reviewer #3: No

**********

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Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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Reviewer #2: Yes

Reviewer #3: Yes

**********

5. 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: Toru KOJIMA et al aimed to evaluate the prognostic impact of surgical resection of recurrent ICC using a retrospective approach including 345 cases of ICC who underwent hepatectomy with curative intent in 17

institutions.

The study is of interest in a difficult cancer field with limited therapeutic options.

Authors highlight those who have a late, intrahepatic recurrence who are ideal candidate for surgery with acceptable outcomes.

I have only minor comments:

Abstract is confusing in the report of the survival and recurrence rate.

Table 1 is not properly formatted.

Reviewer #2: I read the manuscript by Kojima et al with great interest. The study is a multi center study with a large cohort of intrahepatic CCA.

I think the study is well performed and cohort number is big enough, However the tables are arranged in a strange style that it is VERY hard to follow. Therefore they need to re-do all tables. Figure are nice and clear.

Reviewer #3: This paper reported the result of retrospective study conducted in 17 surgical centers from Japan focused on recurrence patterns and treatment modalities for recurrent ICC. A total of 345 cases of ICC who underwent hepatectomy were retrospectively analyzed. Treatment modalities for recurrence comprised surgical resection in only 28 of the patients, non-surgical treatment in n=134, and best supportive care (BSC) in n=61.  In subgroup analyses, surgical resection may have positive prognostic impacts on intra and extrahepatic recurrences, and even on early recurrence.  Although the efforts of the authors are worthy of consideration, both the design of the study, both the limited number of patients which underwent surgery for recurrence, are serious limitations potentially associated with biased conclusions. 

The design of the study and the very low number (28 subjects; less than 10% of the resected subjects and average 12% of the recurrent subjects) are serious limitations of the study in view of the aim. The claim of the conclusion seems overstated with respect to the results and the evidence provided. Indeed, patients undergoing surgery for recurrence are likely to have been diagnosed in an early phase, may have better general condition which allow the surgery, and no advanced underlying liver disease, with respect to the non resected recurrent patients. Please analyze confounder factors which may have influenced the decision making. 

The current accepted classification of the CCA based on location identifies iCCA, perihilar CCA and distal CCA. The origin of the second order branches of the biliary tree define the iCCA vs pCCA. Thus it is not clear whether pCCA has been misclassified as iCCA in this study. Please explain.  

Please provide an accurate definition of the hilar-type ICC. 

Is the histomorphology subtype, small bile duct type vs large bile type, associated with the recurrence rate.

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

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PLoS One. 2020 Sep 3;15(9):e0238392. doi: 10.1371/journal.pone.0238392.r002

Author response to Decision Letter 0


5 Aug 2020

Aug 3, 2020

Gianfranco D. Alpini

Academic Editor

PLOS ONE

Manuscript ID: PONE-D-20-19960

Title: Efficacy of surgical management for recurrent intrahepatic cholangiocarcinoma: A multi-institutional study by the Okayama study group of HBP surgery

Authors: Kojima T et al.

Dear Dr. Alpini:

Thank you for your e-mail of July 17, 2020. We were pleased to know of your positive evaluation of our manuscript and its potential acceptance for publication in PLOS ONE, subject to adequate revision and response to the reviewers' comments.

Based on your instructions, we uploaded the clean and marked files of the revised manuscript. We also pasted in the allocated space on the website our point-by-point responses to the comments raised by the reviewer.

To allow easy access to our response to the comments raised by the reviewer, we also include a copy of our response in this letter. Essentially, we agreed with all the comments raised by the reviewer.

We take this opportunity to thank the reviewer for the hard work. We also thank you for allowing us to resubmit a revised copy of the manuscript.

I hope that the revised manuscript is now acceptable for publication in PLOS ONE.

Sincerely Yours,

Yuzo UMEDA, MD, PhD

Okayama University Graduate School of Medicine and Dentistry

Department of Gastroenterological Surgery

Shikata-cho, Okayama-shi, Okayama 700-8558, JAPAN

E-mail: y.umeda@d9.dion.ne.jp

=================================

Point-by-point response to the comments of Reviewer 1

We thank the reviewer for evaluating our manuscript. The following text describes our responses to the comments made by the reviewer.

1. The reviewer recommended a comprehensive statement about survival and recurrence rate in the Abstract. Accordingly, we changed the phrase “post-recurrence survival rates” to “survival rates after recurrence”.

Page 3, line 10 in the Abstract section.

2. We apologize for our inadequate table content. We mounted the proper formatted table 1, 2, and 3.

Page 8, Table 1 was inserted as the proper format.

Page 10-11, Table 2 was inserted as the proper format.

Page 12-13, Table 3 was inserted as the proper format.

=================================

Point-by-point response to the comments of Reviewer 2

We thank the reviewer for evaluating our manuscript. The following text describes our responses to the comments made by the reviewer.

1. We apologize for our inadequate table contents.

We modified all tables and submitted the proper formatted table 1, 2, and 3 in the revised document.

Page 8, Table 1 was inserted as the proper format.

Page 10-11, Table 2 was inserted as the proper format.

Page 12-13, Table 3 was inserted as the proper format.

=================================

Point-by-point response to the comments of Reviewer 3

We thank the reviewer for evaluating our manuscript and greatly appreciated the reviewer's very important and worthwhile comments. The following text describes our responses to the comments made by the reviewer. The line number mentioned in the response to the comment refers to the small-size number that appears on the left margin of the text of the revised manuscript.

1. As noted by the reviewer, patients undergoing surgery for recurrence had a lower rate of Hilar type ICC and did not undergo major hepatectomy compared to non-resected recurrent patients, and this may have influenced the underlying remnant liver function in their decision-making. In results and discussion, these aspects were added.

Page 15, line 8-10 in the discussion section.

2. We appreciate the valuable comments, as the Reviewer pointed out ‘the definition of hilar/peripheral ICC’ is a very important issue. Firstly, the tumor involving hilar bile duct were not included. And classification of hilar/peripheral type was practically based on preoperative imaging. So we provide the accurate definition of hilar/peripheral type ICC in this study.

Page 5, line 20 to Page 6 line 2 in the materials and methods section.

3. We agree with the prognostic impact of histomorphological subtypes. Unfortunately, due to the limitation of multicenter retrospective study, it was not possible to identify these subtypes in all resected cases.

Therefore, we added previous articles reporting on the correlation between tumor localization and histomorphology as a reference. The recurrence rate of the large bile type, represented by the Hilar type, was higher than that of the small bile type, represented by the peripheral type (n=94 [75.2%] vs n=129 [58.6%], p=0.0023).

We added reference #31-34 as a new reference.

Page 15, line 3-11 in the discussion section.

Attachment

Submitted filename: PlosOne Response to Reviewers.doc

Decision Letter 1

Gianfranco D Alpini

17 Aug 2020

Efficacy of surgical management for recurrent intrahepatic cholangiocarcinoma: A multi-institutional study by the Okayama study group of HBP surgery

PONE-D-20-19960R1

Dear Dr. Yuzo Umeda,

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.

An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

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Kind regards,

Gianfranco D. Alpini

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 #3: All comments have been addressed

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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 #3: (No Response)

**********

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

Reviewer #3: (No Response)

**********

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 #3: (No Response)

**********

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 #3: (No Response)

**********

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 #3: (No Response)

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Reviewer #3: No

Acceptance letter

Gianfranco D Alpini

25 Aug 2020

PONE-D-20-19960R1

Efficacy of surgical management for recurrent intrahepatic cholangiocarcinoma: A multi-institutional study by the Okayama study group of HBP surgery

Dear Dr. Umeda:

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on behalf of

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Academic Editor

PLOS ONE

Associated Data

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

    Supplementary Materials

    S1 Fig. Overall and recurrence-free survival curves.

    (TIFF)

    Attachment

    Submitted filename: PlosOne Response to Reviewers.doc

    Data Availability Statement

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


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