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

Background/aim: 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. Materials and methods: 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. Results: 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. Conclusion: 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.