Outcomes with adjuvant chemotherapy in patients with early-stage biliary tract cancers: An NCDB analysis.

e16302 Background: Biliary tract cancers (BTCs) are a heterogeneous group of malignancies, collectively associated with poor prognosis. Treatment typically consists of curative intent surgery for eligible candidates. Based on the landmark BILCAP trial, capecitabine is currently used as an adjuvant therapy for pts with BTCs. However, the trial included a small number of pts with early-stage disease. Additionally, the staging system used for the trial was updated since. Methods: This retrospective review was based on the National Cancer Data Base (NCDB) participant user file (PUF) from 2014 to 2023. Patients (pts) were identified using codes for intrahepatic biliary, extrahepatic biliary, or gallbladder adenocarcinoma who underwent curative intent surgical resection and had documented chemotherapy status. Only node-negative (N0) disease, pathological stage T1 or 2 were included. Pts were categorized by receipt of adjuvant chemotherapy versus no chemotherapy. Overall survival was evaluated using Kaplan–Meier survival analysis. Analysis of the NCDB PUF is exempt from IRB review. Results: A total of 11,111 pts were identified. 79.3% were White; 44.3% were male; mean age was 67.9years. 2,975 (26.8%) had intrahepatic cholangiocarcinoma (CCA), 2,687 (24.5%) extrahepatic CCA, and 5,449 (49.0%) had gallbladder adenocarcinoma. 9,237 (85.5%) had negative margins; 6,093 (75.7%) had negative LVI. As for size, 3,525 (38.2%) had tumors 2cm or less, 3,953 (42.8%) had tumors between 2 and 5cm, and 1,760 (19.0%) had tumors larger than 5cm. 6,932 pts (62.4%) received adjuvant chemotherapy. A trend toward improved survival was observed across most groups. Statistical significance was associated for T1a and T2a with negative LVI; T1a, T2a, and T2b with negative margins; and T1a and T1b intrahepatic CCA, T2a and b extrahepatic CCA, T2a and b gallbladder adenocarcinoma. The remaining groups had low numbers of pts, and the survival analyses were either not performed due to low numbers or were not statistically significant. Conclusions: Despite the limited retrospective nature of this analysis, adjuvant chemotherapy appears to be associated with improved survival in pts with early-stage CCAs, including those with favorable tumor features. Pt and tumor specific features should be considered individually.