Incidental gallbladder cancer at cholecystectomy: when should the surgeon be suspicious?

Background: Preoperative predictors of incidental gallbladder cancer (iGBC) have been poorly defined despite the frequency with which cholecystectomy is performed. The objective of this study was to define the incidence of and consider risk factors for iGBC at cholecystectomy.

Methods: The American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) database (2005-2009) was used to identify all patients who underwent cholecystectomy (N = 91,260). Patients with an International Classification of Diseases, Ninth Revision, diagnosis of gallbladder malignancy who underwent a laparoscopic cholecystectomy (LC; n = 80,924) or open cholecystectomy (OC; n = 10,336) alone were included.

Results: The incidence of iGBC was 0.19% (n = 170) for all cholecystectomy cases, but 0.05% at LC, 0.60% at LC converted to OC (P < 0.001 vs LC), and 1.13% at OC (P < 0.001 vs others). Patients undergoing OC were 17.3 times more likely to have iGBC than LC patients. Age 65 years or older, Asian or African American race, ASA (American Society of Anesthesiologists) class 3 or more, diabetes mellitus, hypertension, weight loss more than 10%, alkaline phosphatase levels 120 units/L or more, and albumin levels 3.6 g/dL or less were associated with iGBC. Multiple logistic regression identified having an OC, age 65 years or older, Asian or African American race, an elevated alkaline phosphatase level, and female sex as independent risk factors. Patients with 1, 2, 3, and 4 of these factors had a 6.3-, 16.7-, 30.0-, and 47.4-fold risk of iGBC, respectively, from a zero-risk factor baseline of 0.03%.

Conclusions: Surgeons' suspicion for GBC should be heightened when they are performing or converting from LC to OC and when patients are older, Asian or African American, female, and have an elevated alkaline phosphatase level.