Adjuvant Therapy Use for Patients With Inadequately Resected T1b-T3 Gallbladder Cancer

Introduction: Up to 90% of patients undergo inadequate resection for incidentally diagnosed T1b-T3 gallbladder cancer (GBC). We evaluated whether adjuvant therapies (ATs) are associated with prolonged overall survival (OS) for patients undergoing inadequate resection of T1b-T3 GBC. Methods: Patients who underwent inadequate resection, defined as simple cholecystectomy, for T1b-T3, Nx-N2, and M0 GBC were identified from the National Cancer Database (2004-2016). Patient characteristics, variables associated with AT use, and OS were described using the chi-square test, multivariable logistical regression, Kaplan–Meier, and Cox proportional hazard models. Results: Of 1386 patients who met inclusion criteria, most received no AT (64%), 20% received chemotherapy (CT), and 16% received chemoradiotherapy (CRT). Patients who received no AT were generally older (51% ≥ 75 y) and had no comorbidities (65% Charlson Comorbidity Index 0). Among those who received AT, CRT rather than CT, tended to be employed for patients who were older (≥75 y) or had more comorbidities (Charlson Comorbidity Index ≥1). Patients with advanced disease (T3, positive lymph nodes, or positive margins) were more likely to receive CRT. For T1b-T3 GBC, any AT was associated with prolonged median OS compared to no AT (22 months versus 15 mo, P < 0.01). Relative to no AT, CT (hazard ratio 0.76, 95% confidence interval 0.67-0.92) and CRT (0.59, 95% confidence interval 0.49-0.72) were associated with decreased risk of death. Conclusions: AT was associated with prolonged OS for patients with inadequately resected T1b-T3 GBC. CRT may have a role in treatment for patients with high-risk disease following inadequate resection of T1b-T3 GBC.