Role of adjuvant radiotherapy in extrahepatic bile duct cancer: A multicenter retrospective study (Korean Radiation Oncology Group 18-14)

Surrogacy of Recurrence-free Survival for Overall Survival as an Endpoint of Clinical Trials of Perioperative Adjuvant Therapy in Hepatobiliary-pancreatic Cancers: A Retrospective Study and Meta-analysis

OBJECTIVE

To assess the correlation between recurrence-free survival (RFS) and overall survival (OS) in the hepatobiliary-pancreatic (HBP) surgical setting to validate RFS as a surrogate endpoint.

BACKGROUND

Reliable surrogate endpoints for OS are still limited in the field of HBP surgery.

METHODS

We analyzed patients who underwent curative resection for HBP disease [986 patients with pancreatic ductal adenocarcinoma (PDAC), 1168 with biliary tract cancer (BTC), 1043 with hepatocellular carcinoma, and 1071 with colorectal liver metastasis] from September 2002 to June 2022. We also conducted meta-analyses of randomized controlled trials of neoadjuvant or adjuvant therapy to validate the surrogacy in PDAC and BTC.

RESULTS

Correlation coefficients between RFS and OS were low for hepatocellular carcinoma ( p = 0.67) and colorectal liver metastasis ( p = 0.53) but strong for PDAC ( p = 0.80) and BTC ( p = 0.75). In a landmark analysis, the concordance rates between survival or death at 5 years postoperatively and the presence or absence of recurrence at each time point (1, 2, 3, and 4 years) were 50%, 70%, 74%, and 77% for PDAC and 54%, 67%, 73%, and 78% for BTC, respectively, both increasing and reaching a plateau at 3 years. In a meta-analysis, the correlation coefficients for the RFS hazard ratio and OS hazard ratio in PDAC and BTC were p = 0.88 ( P < 0.001) and p = 0.87 ( P < 0.001), respectively.

CONCLUSIONS

Three-year RFS can be a reliable surrogate endpoint for OS in clinical trials of neoadjuvant or adjuvant therapy for PDAC and BTC.

Practice guidelines for managing extrahepatic biliary tract cancers

Backgrounds/Aims

Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021.

Methods

Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop.

Results

In November 2021, the finalized draft was presented for public scrutiny during a formal hearing.

Conclusions

The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Adjuvant Chemoradiation in Resected Biliary Adenocarcinoma: Evaluation of SWOG S0809 with a Large National Database

BACKGROUND

There is a paucity of evidence supporting the use of adjuvant radiation therapy in resected biliary cancer. Supporting evidence for use comes mainly from the small SWOG S0809 trial, which demonstrated an overall median survival of 35 months. We aimed to use a large national database to evaluate the use of adjuvant chemoradiation in resected extrahepatic bile duct and gallbladder cancer.

METHODS

Using the National Cancer Database, we selected patients from 2004 to 2017 with pT2-4, pN0-1, M0 extrahepatic bile duct or gallbladder adenocarcinoma with either R0 or R1 resection margins, and examined factors associated with overall survival (OS). We examined OS in a cohort of patients mimicking the SWOG S0809 protocol as a large validation cohort. Lastly, we compared patients who received chemotherapy only with patients who received adjuvant chemotherapy and radiation using entropy balancing propensity score matching.

RESULTS

Overall, 4997 patients with gallbladder or extrahepatic bile duct adenocarcinoma with available survival information meeting the SWOG S0809 criteria were selected, 469 of whom received both adjuvant chemotherapy and radiotherapy. Median OS in patients undergoing chemoradiation was 36.9 months, and was not different between primary sites (p = 0.841). In a propensity score matched cohort, receipt of adjuvant chemoradiation had a survival benefit compared with adjuvant chemotherapy only (hazard ratio 0.86, 95% confidence interval 0.77-0.95; p = 0.004).

CONCLUSION

Using a large national database, we support the findings of SWOG S0809 with a similar median OS in patients receiving chemoradiation. These data further support the consideration of adjuvant multimodal therapy in resected biliary cancers.

Risk Factors for Distant Metastasis in Extrahepatic Bile Duct Cancer after Curative Resection (KROG 1814)

PURPOSE

Risk factors predicting distant metastasis (DM) in extrahepatic bile duct cancer (EHBDC) patients treated with curative resection were investigated.

MATERIALS AND METHODS

Medical records of 1,418 EHBDC patients undergoing curative resection between Jan 2000 and Dec 2015 from 14 institutions were reviewed. After resection, 924 patients (67.6%) were surveilled without adjuvant therapy, 297 (21.7%) were treated with concurrent chemoradiotherapy (CCRT) and 148 (10.8%) with CCRT followed by chemotherapy. To exclude the treatment effect from innate confounders, patients not treated with adjuvant therapy were evaluated.

RESULTS

After a median follow-up of 36.7 months (range, 2.7 to 213.2 months), the 5-year distant metastasis-free survival (DMFS) rate was 57.7%. On multivariate analysis, perihilar or diffuse tumor (hazard ratio [HR], 1.391; p=0.004), poorly differentiated histology (HR, 2.014; p < 0.001), presence of perineural invasion (HR, 1.768; p < 0.001), positive nodal metastasis (HR, 2.670; p < 0.001) and preoperative carbohydrate antigen (CA) 19-9 ≥ 37 U/mL (HR, 1.353; p < 0.001) were significantly associated with inferior DMFS. The DMFS rates significantly differed according to the number of these risk factors. For validation, patients who underwent adjuvant therapy were evaluated. In patients with ≥ 3 factors, additional chemotherapy after CCRT resulted in a superior DMFS compared with CCRT alone (5-year rate, 47.6% vs. 27.7%; p=0.001), but the benefit of additional chemotherapy was not observed in patients with 0-2 risk factors.

CONCLUSION

Tumor location, histologic differentiation, perineural invasion, lymph node metastasis, and preoperative CA 19-9 level predicted DM risk in resected EHBDC. These risk factors might help identifying a subset of patients who could benefit from additional chemotherapy after resection.

Glucose Regulation after Partial Pancreatectomy: A Comparison of Pancreaticoduodenectomy and Distal Pancreatectomy in the Short and Long Term

BACKGRUOUND

Long term quality of life is becoming increasingly crucial as survival following partial pancreatectomy rises. The purpose of this study was to investigate the difference in glucose dysregulation after pancreaticoduodenectomy (PD) or distal pancreatectomy (DP).

METHODS

In this prospective observational study from 2015 to 2018, 224 patients who underwent partial pancreatectomy were selected: 152 (67.9%) received PD and 72 (32.1%) received DP. Comprehensive assessment for glucose regulation, including a 75 g oral glucose tolerance test was conducted preoperatively, and 1, 12, and 52 weeks after surgery. Patients were further monitored up to 3 years to investigate development of new-onset diabetes mellitus (NODM) in patients without diabetes mellitus (DM) at baseline or worsening of glucose regulation (≥1% increase in glycosylated hemoglobin [HbA1c]) in those with preexisting DM.

RESULTS

The disposition index, an integrated measure of β-cell function, decreased 1 week after surgery in both groups, but it increased more than baseline level in the PD group while its decreased level was maintained in the DP group, resulting in a between-group difference at the 1-year examination (P<0.001). During follow-up, the DP group showed higher incidence of NODM and worsening of glucose regulation than the PD group with hazard ratio (HR) 4.29 (95% confidence interval [CI], 1.49 to 12.3) and HR 2.15 (95% CI, 1.09 to 4.24), respectively, in the multivariate analysis including dynamic glycemic excursion profile. In the DP procedure, distal DP and spleen preservation were associated with better glucose regulation. DP had a stronger association with glucose dysregulation than PD.

CONCLUSION

Proactive surveillance of glucose dysregulation is advised, particularly for patients who receive DP.

Patterns of locoregional recurrences and suggestion of the clinical target volume in resected perihilar extrahepatic cholangiocarcinoma

Purpose

To evaluate the patterns of locoregional recurrence (LRR) in patients with perihilar extrahepatic cholangiocarcinoma (PEHC) treated with radical resection and to suggest the optimal target volume for elective nodal irradiation.

Methods

Medical records of PEHC patients who underwent radical resection between January 2000 and September 2021 at five institutions were reviewed. Patients who were confirmed with LRR in the follow-up imaging study were included. The LRR sites were mapped onto the corresponding sites in template computed tomography images. The margin around the vascular structure was investigated to generate the clinical target volume (CTV) covering the common sites of regional recurrences.

Results

A total of 87 LRRs in 46 patients were identified, 29 (33.3%) of which were local recurrences and 58 (66.7%) were regional recurrences. The most common site of local recurrence was the liver resection margin (n = 16), followed by the anastomosis site (n = 8). Regional recurrences were observed most commonly in the para-aortic area (n = 13), followed by in the aortocaval space (n = 11), portal vein area (n = 11), and portocaval area (n = 9). Nodal CTV was generated by adding an individualized margin around the portal vein, aorta, common hepatic artery, celiac artery, and left gastric artery.

Conclusions

The LRR patterns in the resected PEHC were evaluated and specific guidelines for nodal CTV delineation were provided, which may help physicians delineating the target volume in postoperative radiotherapy for PEHC. These findings need further validation in a lager cohort.

American Radium Society (ARS) Appropriate Use Criteria (AUC) for Extrahepatic Cholangiocarcinoma

Although uncommon, extrahepatic cholangiocarcinoma (EHCC) is a deadly malignancy, and the treatment approaches remain controversial. While surgery remains the only cure, few patients are candidates for resection up front, and there are high rates of both local and distant failure following resection. Herein, we systematically review the available evidence regarding treatment approaches for patients with EHCC, including surgery, radiation, and chemotherapy. The evidence regarding treatment outcomes was assessed using the Population, Intervention, Comparator, Outcome, and Study design (PICOS) framework. A summary of recommendations based on the available literature is outlined for specific clinical scenarios encountered by providers in the clinic to guide the management of these patients.