Factors Associated With Surgical Management in Gallbladder Cancer-A Surveillance, Epidemiology, and End Results Medicare-Based Study

Abstract

Introduction: Gallbladder cancer (GBC) incidence is rising, yet prognosis remains poor. Oncological resection of stage T1b or higher improves survival, yet many patients do not receive appropriate resection. This study aims to evaluate factors that may attribute to this discrepancy using the Surveillance, Epidemiology, and End Results-Medicare (SEER-Medicare) database.

Materials and methods: SEER Medicare (2008-2015) patients with GBC stage T1b or higher were classified as receiving cholecystectomy alone (CCY) or cholecystectomy and liver/biliary resection (oncologic resection). Outcomes and overall survival were compared, before and after propensity score matching on baseline characteristics, using Chi-square and Wilcoxon rank-sum tests for categorical and continuous variables, respectively.

Results: We identified 1129 patients of which 830 underwent CCY (58.3% early stage/41.7% late stage) while 299 had complete resection (54.2% early stage/45.8% late stage). CCY patients were more often female (73.4% versus 65.6%; P = 0.0104), ≥80 y old (48.2% versus 22.4%; P < 0.0001), frail (44.5% versus 27.1%; P < 0.0001), treated by general surgeons (98.1% versus 84.9%; P < 0.0001) versus surgical oncologists, not undergoing chemotherapy (72.3% versus 54.5%; P < 0.0001), managed at nonacademic hospitals (51.2% versus 28.4%; P < 0.0001). After matching, oncologic resection demonstrated improved overall survival compared to CCY at 1-y (69.2% versus 47.2%; P < 0.0001), 3-y (42.8% versus 21.1%; P < 0.0001), and 5-y (37.5% versus 17.4%; P < 0.0001).

Conclusions: Most GBC patients may not be receiving appropriate oncological resection, especially patients who are female, older, frail, operated on by a general surgeon, not undergoing chemotherapy, or managed at nonacademic hospitals. Even when adjusting for patient factors, complete resection is associated with overall survival outcomes at multiple endpoints. Limiting sex, age, and frail status as factors and involving surgical oncologists or receiving management at academic centers may increase oncologic resection rates and thus improve survival for GBC patients.

Keywords: Cholecystectomy; Gallbladder cancer; Oncologic resection; Surgical oncologist; Survival.