Risk factors of gallbladder cancer in Karachi-a case-control study

Background:Gallbladder carcinoma (GC) is a relatively rare malignancy worldwide but is the second commonest gastrointestinal cancer in Pakistani women. Gallstones have a positive association with GC but other factors also influence in causation. Methods: This is a retrospective case control study over a period of 19 years. The cases (Group A) were Patients with histopathological proven carcinoma gallbladder (N = 60) and controls were Patients with cholelithiasis but no carcinoma gallbladder on histopathology (N = 120). Multivariate regression analysis was done to calculate the odds ratio, 95% confidence interval and P-Value. A positive relationship was found between size of stone \u3e 1 cm, solitary stone, age \u3e 55 years and multi-parity in women. Results: There were 60 Patients in Group A and 120 Patients in Group B. mean age of diagnosis in Group A Patients was 57 +/- 2.4 years while mean age of diagnosis in Group B Patients was 48 +/- 1.35 years. Sixty seven percent of cancer group Patients were female as compared to 78% females in non-cancer group. In Group A, 69% of female Patients were multiparous (parity of more than 5) while 43% of group B Patients were multiparous. For body mass index (BMI), both groups were not very different in our study population i.e. around 78% Patients in each group has BMI of more than 23 Kg/m2. In Group A, 37% (n = 22) have solitary stones as compared to 15% (n = 18) in group B. similarly Group A Patients has larger stone size as compared to Group B i.e. 59% (n = 36) Patients in Group A have stones of more than 1 cm when compared to 35% (n = 41) Patients in Group B. After using multivariate regression analysis, age more than 55 years (OR - 7.27, p value - \u3c 0.001), solitary stone (OR - 3.33, p value - 0.002) and stone of more than 1 cm (OR - 2.73, p value - 0.004) were found to be independent risk factors for development of gallbladder cancer. Conclusions: Most of the Patients (78%) with GC were female, and the statistically significant risk factors were older age, solitary stones and stones size more than one centimeter. A case can be made for prophylactic cholecystectomy in such a high risk group. However a population based study is required to calculate the true incidence of GC in Karachi and a prospective multi center study is needed to produce strong evidence for screening and prophylactic cholecystectomy