Initial treatment patterns and survival in biliary tract cancer: A retrospective cohort study in Kyoto, Japan.

Purpose We aimed to describe the treatment landscape for biliary tract cancer (BTC), including patient characteristics, initial treatment patterns, and survival outcomes, and examine factors associated with receiving no active anticancer treatment (NT). Methods We conducted a retrospective cohort study of patients diagnosed with BTC between April 2014 and March 2020 identified through cancer registries and linked with the Kyoto City Integrated Database. Patient characteristics, factors associated with NT, and median overall survival (mOS) were analyzed using multivariate logistic regression and Kaplan-Meier methods. Results Among 1367 eligible patients, 30.1% underwent curative surgery, whereas 44.3% received NT. NT was significantly associated with distant metastasis (adjusted odds ratio [AOR] 4.24; 95% CI 2.92-6.15), certified long-term care (AOR 2.34; 1.76-3.10), and age ≥75 years (AOR 2.23; 1.70-2.93). The mOS was 54.6 months in the curative surgery group, 7.7-18.0 months in the noncurative surgical and nonsurgical treatment groups, and 5.2 months in the NT group. Conclusions Over 40% of patients with BTC in Kyoto City received no active treatment and had shorter survival. Older age and certification for long-term care were significantly associated with the selection of no active treatment. These findings describe treatment patterns among older adults with BTC and may help inform future strategies to improve treatment access, supportive care, and early detection.