Gallbladder cancer: incidence and survival in a high-risk area of Chile

Abstract

We assessed population incidence rates 1998-2002 and 5-year survival rates of 317 primary gallbladder cancer (GBC) entered in the population-based cancer registry in Valdivia. We analyzed GBC incidence (Poisson regression) and GBC survival (Cox regression). Cases were identified by histology (69.4%), clinical work-up (21.8%), or death certificate only (8.8%). Main symptoms were abdominal pain (82.8%), jaundice (53.6%) nausea (42.6%), and weight loss (38.2%); at diagnosis, 64% had Stage TNM IV. In the period, 4% of histopathological studies from presumptively benign cholecystectomies presented GBC. GBC cases were mainly females (76.0%), urban residents (70.3%), Hispanic (83.7%) of low schooling <4 years (64.0%). GBC standardized incidence rate per 100,000 (SIR) were all 17.5 (95%CI: 15.5-19.4), women 24.3, and men 8.6 (p < 0.00001); Mapuche 25.0, Hispanic 16.2 (p = 0.09). The highest SIRs were in Mapuche (269.2) and Hispanic women (199.6) with <4 years of schooling. Lowest SIRs were among Hispanic men (19.8) and women (21.9) with >8 years of schooling. Low schooling, female and urban residence were independent risk factors. By December 31, 2007, 6 (1.9%) cases were living, 280 (88.3%) died from GBC, 32 (10.1%) were lost of follow-up. Kaplan Meier Global 5-year survival was: 10.3%, 85% at stage I and 1.9% at stage IV; median survival: 3.4 months. Independent poor prognostic factors were TNM IV, jaundice and nonincidental diagnoses. Our results suggest that women of Mapuche ancestry with low schooling (>50 years) are at the highest risk of presenting and dying from GBC and should be the target for early detection programs.