Incidence, mortality, and survival of gallbladder, extrahepatic bile duct, and pancreatic cancers in Korea: A population-based study from 1999 to 2022

Abstract

Backgrounds/Aims

Biliary tract and pancreatic cancers remain leading contributors to cancer-related mortality in Korea, even though their incidence rates are comparatively low. This study evaluates long-term national patterns in these malignancies utilizing population-based data.

Methods

Information from the Korea Central Cancer Registry was used to assess 258,854 patients newly diagnosed with gallbladder (n = 52,712), extrahepatic bile duct (n = 76,787), and pancreatic (n = 129,355) cancers between 1999 and 2022.

Results

During the period from 1999 to 2022, the crude incidence rates for gallbladder (2.8 to 5.6 per 100,000), extrahepatic bile duct (3.6 to 9.8), and pancreatic cancers (5.5 to 19.1) all showed an upward trend. For pancreatic cancer, the age-standardized incidence rate rose markedly (5.6 to 8.4), whereas it stabilized for extrahepatic bile duct cancer (3.7 to 3.8), and declined for gallbladder cancer (2.9 to 2.2). The distributions of localized and regional disease stages remained largely consistent throughout the study period. There was an increase in the proportion of patients undergoing surgical intervention within the first 4 months post-diagnosis for gallbladder (42.3% to 48.2%) and pancreatic cancer (22.5% to 23.7%), while this proportion slightly declined in extrahepatic bile duct cancer (47.8% to 46.0%). The overall 5-year relative survival rate improved significantly in gallbladder (21.9% to 32.1%) and pancreatic (8.6% to 15.5%) cancers, and showed a modest improvement in extrahepatic bile duct cancer (23.1% to 27.2%).

Conclusions

The crude incidence rates for gallbladder, extrahepatic bile duct, and pancreatic cancers have continuously risen in Korea. While survival rates have improved, the persistently high mortality rates highlight the critical need for earlier diagnosis and advancements in therapeutic approaches.

INTRODUCTION

Since 1999, the Korea Central Cancer Registry (KCCR) has maintained a nationwide cancer incidence database that encompasses more than 98% of all cancer cases in Korea, thereby supporting the generation of reliable cancer statistics [1]. These extensive data sets have facilitated the identification of dynamic cancer trends over time. A significant observation is the rising incidence of pancreatobiliary cancers, which are strongly linked to aging, in the setting of Korea’s progression to a super-aged society. This trend is especially evident with pancreatic cancer, which contrasts with the decreasing age-standardized incidence observed in several other major cancers. In parallel, mortality rates for pancreatobiliary cancers have increased, positioning pancreatic cancer and gallbladder/extrahepatic bile duct cancers as the fourth and sixth most common causes of cancer-related deaths in Korea, respectively [2]. Considering their significant clinical impact and societal costs, pancreatobiliary cancers warrant increased focus.

Nonetheless, obtaining detailed and site-specific epidemiological information continues to be challenging—not only within Korea but also internationally [3,4]. This difficulty is partly attributable to the ways in which cancer statistics are typically reported using the International Classification of Diseases, tenth revision (ICD-10) [5]: for instance, gallbladder cancer (C23) and extrahepatic bile duct cancer (C24) are frequently reported together, whereas intrahepatic cholangiocarcinoma (C22.1)—which exhibits distinct clinicopathological characteristics from hepatocellular carcinoma (C22.0)—is generally classified under the broader category of liver cancer (C22). Consequently, there is a paucity of comprehensive data for each individual type of pancreatobiliary cancer.

To address this knowledge gap, the Korean Association of Hepato-Biliary-Pancreatic Surgery, in partnership with the KCCR, previously published a detailed analysis of the epidemiologic characteristics of pancreatobiliary cancers using cancer registry data spanning 1999 to 2019. To adapt to recent trends in cancer epidemiology, this analysis has now been updated to incorporate data through 2022. Data on intrahepatic bile duct cancer were presented separately within a related article focusing on liver cancer statistics [6].

MATERIALS AND METHODS

Data source

As outlined in our previous report, epidemiological data were sourced from the KCCR, relying on the Korea National Cancer Incidence Database [1,7]. Patients coded as C23 (gallbladder cancer), C24 (extrahepatic bile duct cancer), and C25 (pancreatic cancer) according to the ICD-10 scheme, from 1999 to 2022, were included in this analysis [5]. Since 2006, the KCCR has incorporated the Surveillance, Epidemiology, and End Results (SEER) stage information in its datasets. SEER stage at diagnosis was categorized as localized (invasive cancer limited to the organ of origin), regional (tumor extension beyond the limits of organ of origin), distant (spread to distant areas from the primary tumor), and unknown [8]. The “first course of treatment” consisted of three categories and referred to any documented cancer-directed therapies implemented within 4 months of the initial diagnosis [8]; surgical (surgery only, surgery with chemotherapy, surgery with radiotherapy, surgery with chemotherapy and radiotherapy), non-surgical (chemotherapy only, chemotherapy with radiotherapy, and radiotherapy only), and no active or unknown treatment status [9]. This study protocol received approval from the institution’s human research committee, with a waiver of written informed consent granted due to the retrospective study design (IRB No. NCC2025-0159).

Statistical analysis

The study period was separated into three intervals: period I (1999 to 2005), period II (2006 to 2014), and period III (2015 to 2022). Rates were reported as crude rate (CR) and age-standardized rate (ASR) per 100,000 individuals. CRs were determined by dividing the total number of incident or mortality cases by the mid-year population for the respective years. ASRs were derived as weighted averages of age-specific rates, standardized based on Segi’s world standard population [10]. The annual percent change (APC) of ASRs and the average APC (AAPC), calculated as a weighted mean of APCs over the total study interval, were also assessed. Relative survival rates were calculated using the Ederer II method with slight adjustments [11], based on an algorithm written in Statistical Analysis System (SAS) software provided by Paul Dickman at Karolinska Institutet, Stockholm, Sweden. All statistical tests were performed as two-tailed analyses, and differences were regarded as statistically significant if p < 0.05. Analysis was conducted using SAS 9.4 (SAS Institute, Inc.) and Joinpoint 4.7.0.0 (National Cancer Institute).

RESULTS

Patient characteristics

From 1999 to 2022, 258,854 new cases of gallbladder, extrahepatic bile duct, and pancreatic cancers were identified in Korea. These three malignancies comprised 5.6% (5,661 of 101,856) of all cancer diagnoses in 1999 and 6.3% (17,628 of 282,047) in 2022. Within the category of biliary-pancreatic cancers, 20.4% (n = 52,712) represented gallbladder cancer, 29.7% (n = 76,787) represented extrahepatic bile duct cancer, and 50.0% (n = 129,355) represented pancreatic cancer. More than half of the patients were aged 70 years or older. Females had a higher incidence of gallbladder cancer (male-to-female ratio, 1 : 1.3), whereas a greater proportion of extrahepatic bile duct (1 : 0.8) and pancreatic cancers (1 : 0.9) were observed in males. The proportion of patients who underwent surgery as the initial treatment was greater for gallbladder (43.4%) and extrahepatic bile duct (45.7%) cancers compared with pancreatic cancer (22.4%). Among patients, the percentage diagnosed at localized or regional stage was highest in extrahepatic bile duct cancer (68.9%), followed by gallbladder cancer (53.8%), and lowest in pancreatic cancer (42.6%) (Table 1).

Table 1.

Demographic characteristics

	C23 (Gallbladder) (n = 52,712)	C24 (Extrahepatic bile duct) (n = 76,787)	C25 (Pancreas) (n = 129,355)
Age group (yr)
0–39	518 (1.0)	518 (0.7)	2,595 (2.0)
40–49	2,318 (4.4)	2,805 (3.7)	7,406 (5.7)
50–59	6,931 (13.2)	9,723 (12.7)	20,681 (16.0)
60–69	13,929 (26.4)	20,621 (26.9)	36,074 (27.9)
70–79	17,712 (33.6)	26,373 (34.4)	39,956 (30.9)
≥ 80	11,304 (21.4)	16,747 (21.8)	22,643 (17.5)
Sex
Male	22,859 (43.4)	44,127 (57.5)	69,413 (53.7)
Female	29,853 (56.6)	32,660 (42.5)	59,942 (46.3)
First course of treatment
Surgical	22,899 (43.4)	35,106 (45.7)	28,994 (22.4)
Non-surgical	7,358 (14.0)	6,400 (8.3)	38,755 (30.0)
No active or unknown treatment	22,455 (42.6)	35,281 (46.0)	61,606 (47.6)
SEER stage (2006–2022)a)
Localized	7,691 (18.6)	16,351 (26.0)	13,060 (12.1)
Regional	14,554 (35.2)	27,030 (42.9)	32,879 (30.5)
Distant	14,657 (35.5)	7,896 (12.5)	45,921 (42.6)
Unstaged	4,419 (10.7)	11,744 (18.6)	15,921 (14.8)

Values are presented as number (%).

SEER, Surveillance, Epidemiology, and End Results.

^a)Percentages indicate the relative distribution within the total number of cases by SEER stage classification.

Gallbladder cancer

From 1999 to 2022, the annual number of newly diagnosed patients increased from 1,336 to 2,843, and cancer deaths rose from 877 to 1,718 in both sexes (Fig. 1A). The CR of incidence for both sexes increased from 2.8 per 100,000 to 5.6 (Supplementary Table 1), with a similar upward trend observed in males (2.4 to 5.1) and females (3.2 to 6.0, data not shown). However, the ASR of incidence for both sexes showed a significant decline with an AAPC of −1.1 (95% confidence interval [CI]: −1.6 to −0.6; p < 0.01; Supplementary Table 2), after peaking from 1999 to 2002 (2.9 to 3.3), followed by a steady decline until 2022 (2.2), which became more pronounced from 2012 onward (Supplementary Table 2, Fig. 1B). The CR of mortality for both sexes also increased from 1.9 to 3.4 (Supplementary Table 1). In contrast, the ASR of mortality decreased for both sexes (AAPC, −1.6; 95% CI: −2.5 to −0.7; p < 0.01), with an increase from 1999 to 2002 (1.9 to 2.4), then a declining trend until 2022 (1.2), and the reduction was especially notable from 2019 (Supplementary Table 2).

Fig. 1.

Gallbladder cancer. (A) Annual number of new cases and cancer deaths. (B) CR and ASR for both sexes. (C) Temporal changes in Surveillance, Epidemiology, and End Results (SEER) stage distribution. (D) Temporal patterns of first course of treatment modalities by SEER stage. (E) Five-year relative survival rates stratified by year of diagnosis, age group, and SEER stages. (F) Five-year relative survival rates by first course of treatment and SEER stages. CR, crude rate; ASR, age-standardized rate. **p < 0.01.

The absolute number of patients demonstrated female predominance, with a male-to-female ratio of 1 : 1.3 (Table 1). In contrast, the male-to-female ratio of the ASR of incidence was consistently 1 : 1.0 over time (period I, 1.0; period II, 1.0; and period III, 1.0).

Between 2006 and 2022, a total of 53.8% of patients presented with localized or regional disease (Table 1). From period II to III, the proportion of patients with unstaged disease declined, while the proportion with other disease stages increased (Fig. 1C). After excluding unstaged disease, the proportion diagnosed at the regional stage rose (37.7% to 40.9%), whereas the proportions with localized (21.4% to 20.4%) and distant stages (40.9% to 38.7%) both declined. The percentage of patients who underwent surgery as the initial course of treatment increased from 78.9% to 83.2% in the localized stage and from 60.4% to 70.1% in the regional stage. The proportion of individuals who received no active or unknown treatment decreased across all stages (43.9% to 34.7%) (Fig. 1D).

During period III, the median survival for all stages was 12.0 months, while the median was not reached for the localized stage and was 25.0 months for the regional stage. Comparing periods I to III, the overall 5-year relative survival rate (5YRS) improved significantly over time (21.9% to 32.1%; p < 0.01), with notably increased rates in the localized (71.9% [period II] to 77.2% [period III]; p < 0.01) and regional stages (32.0% to 40.6%; p < 0.01) (Fig. 1E). Subgroup analysis by SEER stage and the initial treatment approach showed that 5YRS was consistently higher in patients who received surgery as the first treatment at each stage. Between periods II and III, the 5YRS significantly increased in the surgical group for both localized (84.6% to 87.4%; p < 0.01) and regional (49.0% to 55.4%; p < 0.01) stages (Fig. 1F, Supplementary Table 3).

Extrahepatic bile duct cancer

From 1999 to 2022, the yearly number of newly diagnosed patients grew from 1,711 to 5,005, while annual cancer deaths increased from 1,569 to 3,499 in both sexes (Fig. 2A). The CR of incidence for both sexes rose from 3.6 to 9.8 (Supplementary Table 4), with an analogous pattern observed in males (4.2 to 11.7) and females (3.1 to 7.9; data not shown). The ASR of incidence in both sexes rose from 1999 to 2018 (3.7 to 4.2, APC, 0.9 [95% CI: 0.6–1.1]; p < 0.01), followed by a decrease through 2022 (3.8; APC, –2.4 [95% CI: –4.5 to –0.3]; p = 0.03) (Supplementary Table 5, Fig. 2B). The crude mortality rate in both sexes increased from 3.3 to 6.8 (Supplementary Table 4). Conversely, the ASR of mortality for both sexes showed a declining trend (AAPC, –1.7 [95% CI: –2.3 to –1.0]; p < 0.01) (Supplementary Table 5).

Fig. 2.

Extrahepatic bile duct cancer. (A) Annual number of new cases and cancer deaths. (B) CR and ASR for both sexes. (C) Temporal changes in Surveillance, Epidemiology, and End Results (SEER) stage distribution. (D) Temporal patterns of first course of treatment modalities by SEER stage. (E) Five-year relative survival rates stratified by year of diagnosis, age group, and SEER stages. (F) Five-year relative survival rates by first course of treatment and SEER stages. CR, crude rate; ASR, age-standardized rate. *p < 0.05, **p < 0.01.

Although the male predominance noted in the crude number of patients (1 : 0.8) was evident, it was more accentuated in the ASR of incidence (1 : 0.5). This greater disparity persisted consistently over time (period I, 0.5; period II, 0.5; and period III, 0.5).

From 2006 to 2022, 68.9% of patients presented with localized or regional disease (Table 1). Between periods II and III, there was a reduction in the proportion of patients with unstaged disease (Fig. 2C). After excluding cases with unstaged disease, the proportion of localized stage declined (32.9% to 31.2%), while proportions of regional (52.0% to 53.2%) and distant (15.1% to 15.6%) stage both rose. The proportion of patients receiving surgery as the first course of treatment in localized stage remained nearly unchanged (47.4% to 47.3%), but decreased in the regional stage (73.5% to 69.0%; Fig. 2D). There was an increase in the proportion receiving non-surgical first course of treatment for both localized (3.3% to 5.9%) and regional (4.4% to 9.0%) stages. The percentage of patients with no active treatment or an unknown treatment plan declined across all stages (45.8% to 42.5%).

In period III, the median overall survival was 17.0 months for all stages and 24.0 months specifically for the localized and regional stages. Across periods I to III, the overall 5YRS did not show a statistically significant increase over time (23.1% to 27.2%; p = 0.22) (Fig. 2E). When stratified by SEER stage and first course of treatment, the 5YRS was consistently higher among patients who underwent surgical first course of treatment at each stage. During periods II to III, the 5YRS improved significantly in the surgical group for both localized (65.0% to 67.1%; p = 0.04) and regional (39.7% to 40.2%; p = 0.01) stages, and also in the regional stage non-surgical group (7.8% to 8.5%; p < 0.01) (Fig. 2F, Supplementary Table 6).

Pancreatic cancer

Between 1999 and 2022, the annual number of newly diagnosed patients rose from 2,614 to 9,780, with cancer deaths increasing from 2,543 to 7,325 among both sexes (Fig. 3A). The CR of incidence for both sexes grew from 5.5 to 19.1 (Supplementary Table 7), and comparable trends were observed in males (6.5 to 19.9) and females (4.6 to 18.3, data not shown). The ASR of incidence demonstrated a significant increase in both sexes (5.6 to 8.4; AAPC, 1.8 [95% CI: 1.6–2.0]; p < 0.01) (Fig. 3B, Supplementary Table 8). This increasing trend in ASR was more pronounced in females (4.0 to 7.4; AAPC, 2.7 [95% CI: 2.5–3.0]; p < 0.01) compared to males (7.9 to 9.6; AAPC, 1.0 [95% CI: 0.5–1.4]; p < 0.01, data not shown). The CR of mortality in both sexes rose from 5.4 to 14.3 (Supplementary Table 7). In contrast, the ASR of mortality remained unchanged in both sexes (AAPC, 0.1 [95% CI: 0.0–0.2]; p = 0.11) (Supplementary Table 8), declined in males (7.7 to 6.9; AAPC, –0.6 [95% CI: –0.7 to –0.4]; p < 0.01), but increased in females (3.9 to 4.6, AAPC, 0.7 [95% CI: 0.5–0.9]; p < 0.01, data not shown).

Fig. 3.

Pancreatic cancer. (A) Annual number of new cases and cancer deaths. (B) CR and ASR for both sexes. (C) Temporal changes in Surveillance, Epidemiology, and End Results (SEER) stage distribution. (D) Temporal patterns of first course of treatment modalities by SEER stage. (E) Five-year relative survival rates stratified by year of diagnosis, age group, and SEER stages. (F) Five-year relative survival rates by first course of treatment and SEER stages. CR, crude rate; ASR, age-standardized rate. **p < 0.01.

The crude patient numbers demonstrated a higher prevalence in males (1 : 0.9). The overall male-to-female ASR incidence ratio was 1 : 0.7, showing a gradual rise across the periods (period I, 0.5; period II, 0.6; and period III, 0.7).

From 2006 to 2022, 42.6% of patients presented with localized or regional disease (Table 1). During the transition from periods II to III, there was a decline in the proportion of unstaged disease, accompanied by an increase in the proportions of other stages (Fig. 3C). After excluding unstaged disease, the proportion with localized stage increased (12.9% to 15.1%), the regional stage proportion remained almost unchanged (36.0% to 35.6%), and the distant stage proportion decreased (51.1% to 49.3%). The proportion receiving surgical first course of treatment in the localized stage increased (33.7% to 45.1%, while the regional stage remained largely stable (45.8% to 45.7%; Fig. 3D). In contrast, non-surgical first course of treatment increased in localized stage from 15.0% to 16.1%, with a more prominent rise in regional stage (21.0% to 30.5%). The proportion of patients receiving no active or unknown treatment declined across all stages (50.4% to 40.0%).

In period III, the median survival was 9.0 months across all stages, 32.0 months for patients with localized disease, and 17.0 months for those with regional disease. From period I to III, the overall 5YRS increased significantly (8.6% to 15.5%; p < 0.01), particularly within the localized (30.1% to 47.1%; p < 0.01) and regional (12.8% to 20.8%, p < 0.01; Fig. 3E) stages. When analyzed according to the SEER stage and initial treatment modality, the 5YRS was notably higher among individuals who underwent surgery as the first course of treatment, regardless of stage. Between periods II and III, this group exhibited a significant rise in 5YRS for both localized (64.4% to 76.6%; p < 0.01) and regional disease (23.4% to 35.4%; p < 0.01) (Fig. 3F, Supplementary Table 9). A statistically significant improvement in 5YRS was also observed in the non-surgical first course of treatment group for localized (3.7% to 11.4%; p < 0.01) and regional stages (3.4% to 10.6%; p < 0.01).

DISCUSSION

In Korea, the annual incidence and mortality associated with gallbladder, extrahepatic bile duct, and pancreatic cancers have continued to rise, cumulatively representing 6.3% of all cancer cases in 2022. These increasing trends emphasize the substantial burden of these malignancies and highlight the necessity for improved strategies and heightened awareness, especially given their generally unfavorable prognosis. Of particular note, pancreatic cancer has demonstrated a pronounced elevation in ASR, most prominently among female, which contrasts with the generally declining ASRs for most other major cancers in Korea since 2012 [1]. The elevated pancreatic cancer incidence among female is likely associated with increased exposure to lifestyle and environmental risk factors—including smoking, alcohol intake, red and processed meat consumption, and obesity—reflecting the effects of population aging as well as enhanced societal engagement by female [12,13]. Additional studies are warranted to substantiate these associations and investigate their biological mechanisms. In contrast, while the ASR for gallbladder and extrahepatic bile duct cancer incidence has declined in recent years, the crude incidence rates continue to rise, largely attributable to population aging.

ASR of mortality has exhibited a downward trend for gallbladder and extrahepatic bile duct cancers, but the reduction in extrahepatic bile duct cancer mortality has stabilized since 2013, and mortality due to pancreatic cancer has remained essentially unchanged throughout the study period.

The distribution of stages according to the SEER summary stage at diagnosis remained mostly consistent over time, except for a significant decrease in the number of unstaged cancers. This indicates that, despite improvements in diagnostic technologies and expanded healthcare access, achieving early detection continues to be a major obstacle. For pancreatic cancer specifically, there was a modest rise in the proportion of localized-stage cases.

With respect to the first course of treatment, the proportion of patients who underwent surgery increased for both gallbladder and pancreatic cancers. In contrast, the surgical treatment rate for extrahepatic bile duct cancer did not exhibit a notable increase. Notably, for pancreatic cancer, the percentage of localized-stage patients receiving surgery as their initial treatment rose by 11.4%, whereas there was no significant increase among regional-stage patients; rather, the use of non-surgical treatments became more prevalent. Considering that cancer registry data capture only the treatments administered within the first four months, the growing use of neoadjuvant therapy in recent years has likely resulted in many patients, who ultimately underwent surgery, being initially categorized as having received non-surgical treatments. This explanation is further supported by the observed improvement in 5YRS for both surgical and non-surgical first course of treatment groups.

Survival outcomes have improved over time, with the most significant progress observed in gallbladder and pancreatic cancers. Pancreatic cancer exhibited the greatest improvement among these. However, interpretation of these results should be approached cautiously, as the cohort includes both ductal adenocarcinomas and neoplasms with inherently better prognoses (e.g. endocrine, mucinous or cystic tumors) [9]. Nevertheless, the data suggest incremental improvements in pancreatic cancer prognosis, with a 17% increase in 5YRS for localized-stage disease and an 8% increase in regional-stage cases. Upon analysis by treatment approach, 5YRS improved by roughly 12% among patients undergoing surgery as their initial treatment, and by about 7% for those receiving a non-surgical initial regimen in both localized and regional stages. The observed survival advantage following surgery is plausibly linked to the favorable results associated with adjuvant FOLFIRINOX [14]. Furthermore, it is likely that a subset of patients categorized as non-surgical actually received neoadjuvant therapy followed by surgery, potentially contributing to the reported improvement in survival. In contrast, extrahepatic bile duct cancer exhibited minimal changes in surgical intervention rates or 5YRS, underscoring the necessity of promoting earlier detection to facilitate surgical management whenever feasible.

This study has several limitations. Firstly, the cancer registry does not include longitudinal treatment data or detailed clinical information. The registry collects data only on cancer-directed treatments administered within the first four months following diagnosis. Consequently, if patients receive surgery or chemotherapy beyond four months after initial diagnosis, these treatments may not be recorded in the registry, which could result in gaps or inaccuracies in the documented treatment data. This issue also introduces the possibility of misclassification, especially for patients undergoing delayed surgery after neoadjuvant therapy, as these cases might not be correctly categorized as having received surgical treatment. Secondly, the absence of detailed clinical variables (e.g. TNM stage) restricts the ability to perform more comprehensive analyses of prognostic factors. Finally, historical misclassification of Klatskin tumors (M8162/3) may have led to inflated estimates of intrahepatic bile duct cancer incidence and underreporting of extrahepatic bile duct cancer rates [15-17]. For this review, we adhered to the original ICD-O-3 classification for Klatskin tumors, although ICD-O-3.2 has reclassified them solely as extrahepatic bile duct cancers in Korea since 2021 [18]. This reclassification may affect the interpretation of future incidence trends.

In summary, the incidence and cancer-related mortality of gallbladder, extrahepatic bile duct, and pancreatic cancers have continued to increase in Korea. Although patient prognosis has shown gradual improvement, the distribution of SEER stages has exhibited minimal change over time. This suggests that rates of early detection have not improved despite advances in diagnostic capability and increased access to healthcare. Among these cancers, extrahepatic bile duct cancer experienced the smallest improvement in 5YRS. Pancreatic cancer demonstrated the sharpest rise in ASR of incidence, particularly among female patients. Notably, its 5YRS improved significantly, especially for localized-stage patients who received surgery as their initial therapy. As surgical treatment is associated with markedly better survival outcomes compared to non-surgical or no therapy, approaches that enhance early diagnosis and increase the percentage of operable patients receiving surgery as the first line of treatment will be vital to improving long-term survival outcomes.

SUPPLEMENTARY DATA

Supplementary data related to this article can be found at https://doi.org/10.14701/ahbps.25-135.

Funding Statement

FUNDING This work was supported by a research grant from the National Cancer Center Foundation, donated by the Korean Association of Hepato-Biliary-Pancreatic Surgery, and National Cancer Center (Grant No. 2510681-1), Republic of Korea.