Cholecystectomy and risk of pancreatic cancer: a meta-analysis of observational studies.
OBJECTIVE
Data from epidemiological studies related to the association of cholecystectomy and pancreatic cancer (PaC) risk are inconsistent. We conducted a meta-analysis of observational studies to explore this relationship.


METHODS
We identified studies by a literature search of Medline (from 1 January 1966) and EMBASE (from 1 January 1974), through 30 June 2011, and by searching the reference lists of pertinent articles. Summary relative risks with their 95% confidence intervals were calculated with a random-effects model. Between-study heterogeneity was assessed using Cochran's Q statistic and the I (2).


RESULTS
A total of 18 studies (10 case-control studies, eight cohort studies) were included in this meta-analysis. Analysis of these 18 studies found that cholecystectomy was associated with a 23% excess risk of PaC (SRR = 1.23, 95% CI = 1.12-1.35), with moderate heterogeneity among these studies (p (heterogeneity) = 0.006, I (2) = 51.0%). Sub-grouped analyses revealed that the increased risk of PaC was independent of geographic location, gender, study design and confounders. There was no publication bias in the current meta-analysis.


CONCLUSIONS
The results of this meta-analysis suggest that individuals with a history of cholecystectomy may have an increased risk of pancreatic cancer.
Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai, China.
Genlai
G
Lin
Zhaochong
Z
Zeng
Xiaolin
X
Wang
Zheng
Z
Wu
Jian
J
Wang
Chenggang
C
Wang
Qiao
Q
Sun
Yixing
Y
Chen
Hongbo
H
Quan
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002763:Cholecystectomy / Q000009:adverse effects / Q000706:statistics & numerical data*; D015331:Cohort Studies; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors; D055815:Young Adult