Background: Adjuvant chemotherapy (AC) is recommended following surgical resection of gallbladder cancer regardless of stage. However, stage-specific benefits of AC in gallbladder cancer are unclear.
Patients and methods: Patients with resected pathologic stage I-III gallbladder cancer were identified using the 2006-2015 National Cancer Database. Utilization trends, predictors of use, and impact of AC on overall survival (OS) were determined.
Results: A total of 5656 patients were included. Use of AC increased from 9.9% in 2006 to 24.2% in 2015 (OR 2.91; 95% CI 2.06-4.09; p < 0.001). However, only 17.5% of patients overall and only 32.4% of node-positive (stage IIIb) patients received AC. Patients receiving AC were younger and had fewer comorbidities, shorter hospitalizations, more advanced disease, and more margin-positive resections (all p < 0.01). Higher pathologic T stage and positive nodal status represented the greatest independent predictors of receipt of AC. While AC demonstrated no OS advantage for stage I patients (p = 0.83), AC was associated with improved OS among stage II patients (p = 0.003), though this impact was not independently associated with improved OS on multivariable analysis. AC was independently associated with improved OS among stage IIIb patients, with a 30% reduction in risk of death (HR 0.70; 95% CI 0.58-0.83; p < 0.001). Younger age, fewer comorbidities, and shorter hospitalization all predicted receipt of AC among stage IIIb patients (all p < 0.05).
Conclusions: Systemic therapy remains underprescribed, in particular among patients that would seem to benefit most. Adjuvant chemotherapy likely improves survival in node-positive gallbladder cancer, but its utility in the treatment of node-negative disease has not been demonstrated.