# Assessment of heterogeneity according to hospital or medical experience factors in outcomes of chemotherapy for advanced biliary tract cancer: a post-hoc analysis of JCOG1113

## TL;DR

This study analyzed data from a cancer trial to see if hospital factors affected patient outcomes, finding no significant differences.

## Contribution

The study is the first to assess inter-institutional heterogeneity in biliary tract cancer chemotherapy outcomes in a phase III trial.

## Key findings

- No significant trends were found between hospital volume and overall survival.
- Experience in medical oncology did not significantly affect progression-free survival.
- Results support the generalizability of the JCOG1113 trial outcomes.

## Abstract

JCOG1113 is a randomized phase III trial that showed non-inferiority of gemcitabine plus S-1 to gemcitabine plus cisplatin in patients with advanced biliary tract cancer. Assessment of inter-institutional heterogeneity in chemotherapy contributes to confirm generalizability and reliability of the study itself. However, there have been no studies conducted to assess the heterogeneity among participating centers in randomized phase III trials for biliary tract cancer.

The objective of this post-hoc analysis was to assess the inter-institutional heterogeneity in the overall survival and progression-free survival of patients with advanced biliary tract cancer treated with first-line chemotherapy in the JCOG1113 trial. The heterogeneity in the overall survival and progression-free survival was assessed according to three factors: hospital volume, experience in medical oncology and experience in biliary intervention. A total of 300 advanced biliary tract cancer patients were analyzed. There were no statistically significant trends observed between hospital volume, experience in medical oncology, or experience in biliary intervention and overall survival (hospital volume: adjusted trend P value = 0.6796; experience in medical oncology: adjusted trend P value = 0.4092; experience in biliary intervention: adjusted trend P value = 0.6112). Similarly, no statistically significant trends were observed between these factors and progression-free survival (hospital volume: adjusted trend P value = 0.3000; experience in medical oncology: adjusted trend P value = 0.1108; experience in biliary intervention: adjusted trend P value = 0.2898).

This study revealed no inter-institutional heterogeneity in the overall survival and progression-free survival in the JCOG1113 study population of advanced biliary tract cancer patients.

Our study revealed no significant inter-institutional heterogeneity of the survival outcomes in advanced biliary tract cancer patients of the JCOG1113 study, supporting the generalizability of its results.