Trends in incidence, treatment and survival of gallbladder cancer; a nation-wide cohort study

Background: Gallbladder cancer (GBC) is rare tumour with a poor prognosis and data from the Western world on the incidence, treatment, and survival is scarce. Population-based data is essential in order to identify prognostic factors, optimise treatment strategies and ultimately improve the prospects of GBC patients. Methods: Data on all patients diagnosed from 2005 - 2016 with invasive GBC was provided by the Netherlands Cancer Registry. Trends in incidence, treatment strategies and overall survival (OS) were analysed using chi-square testing, Kaplan - Meier methods and Cox Regression Analysis. Results: Age-standardised incidence of GBC varied from 0.6 to 0.9 per 100.000 person years and did not change significantly during the study period. Between 2005 - 2009 and 2020 - 2016, more early (pT1/T2) GBC patients received radical as opposed to simple cholecystectomy (19% vs 33%, P<0.001) and more palliative chemotherapy was administered to metastatic patients (11% vs. 29%, P<0.001). OS across the entire cohort was 5.5 months and increased from 4.8 months to 6.1 months (P=0.017). OS in resected, non-resected non-metastatic and metastatic patients was 23.7, 3.6 and 2.9 months respectively. Radical surgery (i.e. extended cholecystectomy and hepatoduodenal lymphadenectomy, either single or two-stage procedure) in early GBC increased OS from 18.3 to 76.7 months (P<0.001). In non-resected and metastatic disease, palliative chemotherapy increased survival from 3.6 to 7.7 (P=0.011) and 2.1 to 7.3 (P<0.001) months respectively. Poor prognostic factors in resected GBC were increasing age, increasing T stage, poor differentiation, the presence of lymph node metastases and irradical resection. Conclusion: The prognosis of GBC is poor and no clinically relevant improvement has been made in the past decade. Radical cholecystectomy in early GBC and palliative chemotherapy in non-resected and metastatic GBC appear to improve prognosis but were infrequently used. Survival of GBC patients per stage.