# Chemotherapy tolerance and continuity are prognostic for overall survival in patients with localized and advanced biliary tract cancer

## TL;DR

This study shows that chemotherapy tolerance and continuity significantly impact survival in patients with biliary tract cancer, both in early and advanced stages.

## Contribution

The study provides real-world insights into chemotherapy eligibility, patterns, and survival outcomes in biliary tract cancer patients over five years.

## Key findings

- Only 52.5% of resected BTC patients received adjuvant chemotherapy, and 29% could not complete planned cycles.
- In advanced BTC, 70.7% needed dose reductions, and chemotherapy continuity was strongly associated with better overall survival.
- The cisplatin-gemcitabine regimen and receiving second-line chemotherapy were significantly linked to improved survival.

## Abstract

Biliary tract cancers (BTC) are relatively rare and have a poor prognosis in both localized and metastatic settings. Clinical trials tend to include patients who can tolerate treatments; however, chemotherapy eligibility, patterns, and survival may differ in the real world. The present study provides a 5-year overview of chemotherapy eligibility, patterns, tolerance, and survival in patients with resected and advanced BTCs.

Included in the study were patients with resectable or advanced BTC (excluding ampullary cancers) diagnosed between 2019 and 2024. The demographic/clinical characteristics, chemotherapy eligibility, patterns, and survival outcomes of the patients were evaluated.

Of the 151 patients included in the study, 61 (40.7%) had resected BTC and 90 (59.3%) had advanced BTC. Among the patients with resected BTC, only 52.5% received adjuvant chemotherapy, 38.7% needed dose reductions, and 29% could not complete the planned cycles. Median recurrence-free survival and overall survival (OS) were 24.1 months (95% confidence interval (CI): 11.4–58.0) and 59 months (95% CI: 38.4–59) in patients with resected BTC, respectively, for all patients. In a multivariable analysis, only the number of adjuvant chemotherapy cycles was associated with OS [Hazard ratio (HR):0.63 (95% CI: 0.39–1.00), p=0.050]. Among the patients with advanced disease, 16.7% were not eligible for first-line chemotherapy, and 70.7% needed dose reduction. The median number of cycles was three (0–18); grade 3–4 adverse events were observed in 52% of the patients; and median progression-free survival and OS were 4.3 months (95% CI: 3.3–5.0) and 9.4 months (95% CI: 5.9–13.7) for all patients, respectively. Only 36.7% were able to receive second-line treatment. The number of first-line chemotherapy cycles [HR: 0.58 (95% CI: 0.45–0.76), p < 0.001]/discontinuation due to toxicity [HR: 3.26 (95% CI: 1.34–7.93), p = 0.009], cisplatin-gemcitabine regimen [HR: 0.10 (95% CI: 0.01–0.58), p<0.001], and receiving second-line chemotherapy [HR: 0.28 (95% CI: 0.11–0.68), p < 0.001] were significantly associated with OS in multivariable analyses.

This study shows that a significant proportion of patients with BTC are not eligible or intolerant to chemotherapy in the real world. Maintaining the planned treatment, even with dose reduction, is associated with better OS.