Background:Carcinoma of the gallbladder is the fifth commonest gastrointestinal tract cancer and is endemic in several countries. An association of chronic typhoid carriage and carcinoma of the gallbladder has been reported.
Aim: To clarify whether chronic Salmonella typhi carrier state is associated with carcinoma of the gallbladder.
Methods:A systematic search was conducted using MEDLINE, PubMed, EMBASE, Current Contents Connect, Cochrane library, Google Scholar, Science Direct, and Web of Science. Original data were abstracted from each study and used to calculate a pooled event rate (ER), odd ratio (OR) and 95% confidence interval (95% CI).
Results:Most of the studies were from South Asia. When a subgroup analysis was performed according to region, a significant association was observed in South East Asia (OR: 4.13, 95% CI: 2.87-5.94). Based on study design we performed a subgroup analysis. The summary OR for cohort studies was 19.48 (95% CI: 0.27-1418.18) on the other hand for the case control studies the OR was 3.08 (95% CI: 1.67-5.71). However, the overall OR was 4.28(95% CI: 1.84-9.96).
Chronic Salmonella typhi carrier state was associated with carcinoma of the gallbladder based on detection methods of Salmonella typhi by antibody levels (OR: 3.52, 95% CI: 2.48-5.00) and even more so on culture (OR: 4.14, 95% CI: 2.41-7.12). On the other hand, a past medical history of typhoid was not related with carcinoma of the gallbladder (OR: 3.33, 95% CI: 0.77-14.38). The association was prominent in healthy controls (OR: 5.86, 95% CI: 3.84-8.95) when compared to controls with gallstones (OR: 2.71, 95% CI: 1.92-3.83).
Conclusions:Chronic typhoid carrier state is an important risk factor among patients with carcinoma of the gallbladder.