Clinicopathological Characteristics and Prognosis of Signet Ring Cell Carcinoma of the Gallbladder

Background: Signet ring cell carcinoma (SRC) is a rare histological subtype of gallbladder adenocarcinoma. The current study evaluates the clinicopathologic features and prognosis of SRC. Methods: Patients with adenocarcinoma of the gallbladder were identified in the Surveillance, Epidemiology, and End Results database from 1973 to 2016. Overall survival (OS) was assessed using Cox regression method. Results: Of 22,781 gallbladder adenocarcinomas retrieved, 377 (1.7%) were SRC and the other 22,404 were non-SRC. SRC was more significantly associated with older age, female gender, poor differentiation, advanced tumor stage, lymph node metastasis, distant metastasis, and advanced AJCC stage. The 1-, 2- and 5-year OS was 28.1%, 16.8% and 7.2% for SRC vs. 34.9%, 23.1% and 13.2% for non-SRC, respectively ( P = 0.002). Multivariable analysis showed that the SRC histology was independently associated with a dismal prognosis (hazard ratio [HR] 1.256, P = 0.021). Surgery in combination with chemotherapy improved OS of gallbladder SRC patients compared with surgery alone (HR 0.726, P = 0.036) or chemotherapy alone (HR 0.433, P < 0.001). Conclusion: Patients with SRC of the gallbladder have distinct clinicopathological features with poor prognosis. Surgery in combination with chemotherapy can improve survival.