Biliary tract cancers in Olmsted County, Minnesota, 1976-2008

Abstract

Objectives: The epidemiology of biliary tract cancers has changed in the United States in the past several decades. The aim of this study is to evaluate biliary tract cancers with regard to the incidence rates, etiology, treatment, and survival in Olmsted County between 1976 and 2008.

Methods: Community residents over 20 years of age with a newly diagnosed biliary tract cancers were identified using the Rochester Epidemiology Project. Clinical information, including tumor stage, treatment, and survival status was abstracted from the medical records. The incidence rate was calculated considering the entire population of Olmsted County to be at risk and adjusted by age and sex according to US Census 2000 population. Temporal trends of patient survival with biliary tract cancers were assessed.

Results: A total of 116 subjects met the study criteria. The age-sex-adjusted incidence rate of intrahepatic cholangiocarcinoma (ICC) increased from 0.3 to 2.1 (P=0.02) but one of gall bladder (GB) cancer decreased from 4.0 to 2.2 (P=0.04) per 100,000 person-years between 1976 and 2008 (P<0.01). Overall incidence rates of remaining biliary tract cancers have not changed. Overall 59% of patients presented with stage 3 or 4 cancers and a median survival was 6.3 months. Survival in patients with biliary tract cancer has minimally improved from median survival of 4.2-7.7 months between 1976 and 2008 (P=0.05).

Conclusions: In Olmsted County, the incidence of ICC and GB cancer has increased and decreased, respectively. The prognosis remains poor in community residents diagnosed with biliary tract cancers.

Figure 1

Trends in the survival of Olmsted County, Minnesota residents with Biliary Tract Cancer 1976-2008. Figure footnote: The change in survival became significant (p=0.02) when the latter two eras were combined – perhaps reflecting advances (e.g., portal vein embolization) in surgical management in the early 1990s.