title: Risk factors of gallbladder cancer in Karachi-a case-control study.
abstract: 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 > 1 cm, solitary stone, age > 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- < 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.
  
  
  BACKGROUND
  As this was a retrospective review of medical records, as per institution policy, its gives waiver from any registration (ethical/trial).
authors.affiliation: Department of Surgery, Aga Khan University Hospital, Karachi-74800, Pakistan. rehman.alvi@aku.edu
authors.forename: A Rehman
authors.initials: AR
authors.lastname: Alvi
authors.forename: Nadeem Ahmed
authors.initials: NA
authors.lastname: Siddiqui
authors.forename: Hasnain
authors.initials: H
authors.lastname: Zafar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015992:Body Mass Index; D016022:Case-Control Studies; D002763:Cholecystectomy; D005260:Female; D005500:Follow-Up Studies; D005706:Gallbladder Neoplasms / Q000453:epidemiology / Q000209:etiology*; D042882:Gallstones / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010154:Pakistan / Q000453:epidemiology; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult