Epidemiol Health.
2021;43(1):e2021011. 10.4178/epih.e2021011.
Association between gallstones and the risk of biliary tract cancer: a systematic review and meta-analysis
- Affiliations
-
- 1Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea
- 2Division of Cancer Control and Policy, National Cancer Control Institute, National Cancer Center, Goyang, Korea
- 3Seoul National University College of Medicine, Seoul, Korea
- 4Cancer Research Institute, Seoul National University, Seoul, Korea
- 5Department of Epidemiology and Cancer Control, St. Jude Children’s Research Hospital, Memphis, TN, USA
- KMID: 2514971
- DOI: http://doi.org/10.4178/epih.e2021011
Abstract
OBJECTIVES
Biliary tract cancers (BTCs) are rare but highly fatal. Although the etiology of BTC is poorly understood, gallstones are proposed to be a major risk factor. We conducted a systematic review and meta-analysis to examine the associations between gallstone characteristics and BTC risk.
METHODS
We searched the MEDLINE, Embase, and Cochrane Central databases and systematically reviewed cohort and case-control studies published before April 9, 2018. All the included studies reported appropriate risk estimates and confidence intervals (CIs) for associations between the presence, size, number, or duration of gallstones and the risk of BTC, including gallbladder cancer (GBC), extrahepatic bile duct cancer (EBDC), and ampulla of Vater cancer (AOVC). Summary odds ratios (ORs) and their 95% CIs were calculated using a random-effects model in the meta-analysis. Subgroup analyses were conducted to inspect sources of potential heterogeneity, and the Egger test was performed to assess publication bias.
RESULTS
Seven cohort studies and 23 case-control studies in Asian, European, and American populations were included. The presence of gallstones was associated with an increased risk of BTC (OR, 4.38; 95% CI, 3.23 to 5.93; I2=91.2%), GBC (OR, 7.26; 95% CI, 4.33 to 12.18), EBDC (OR, 3.17; 95% CI, 2.24 to 4.50), and AOVC (OR, 3.28; 95% CI, 1.33 to 8.11). Gallstone size (>1 vs. <1 cm; OR, 1.88; 95% CI, 1.10 to 3.22) was significantly associated with the risk of GBC.
CONCLUSIONS
Gallstone characteristics, such as presence, size, and number, are associated with an increased risk of BTC. However, significantly high heterogeneity in the meta-analyses is a limitation of this study.
