Abstract
PURPOSE: The purpose of this study is to understand factors associated with timing of adjuvant therapy for cholangiocarcinoma and the impact of delays on overall survival (OS). METHODS: Data from the National Cancer Database (NCDB) for patients with non-metastatic bile duct cancer from 2004 to 2015 were analyzed. Patients were included only if they underwent surgery and adjuvant chemotherapy and/or radiotherapy (RT). Patients who underwent neoadjuvant or palliative treatments were excluded. Pearson's chi-squared test and multivariate logistic regression analyses were used to assess the distribution of demographic, clinical, and treatment factors. After propensity score matching with inverse probability of treatment weighting, OS was compared between patients initiating therapy past various time points using Kaplan Meier analyses and doubly robust estimation with multivariate Cox proportional hazards modeling. RESULTS: In total, 7,733 of 17,363 (45%) patients underwent adjuvant treatment. The median time to adjuvant therapy initiation was 59 days (interquartile range 45-78 days). Age over 65, black and Hispanic race, and treatment with RT alone were associated with later initiation of adjuvant treatment. Patients with larger tumors and high-grade disease were more likely to initiate treatment early. After propensity score weighting, there was an OS decrement to initiation of treatment beyond the median of 59 days after surgery. CONCLUSIONS: We identified characteristics that are related to the timing of adjuvant therapy in patients with biliary cancers. There was an OS decrement associated with delays beyond the median time point of 59 days. This finding may be especially relevant given the treatment delays seen as a result of COVID-19.