Primary biliary cirrhosis and cancer risk: a systematic review and meta-analysis.Liang Y, Yang Z, Zhong R. Hepatology. 2012 Apr 13. [Epub ahead of print] Several studies indicated that primary biliary cirrhosis (PBC) may be associated with increased risks of some cancers, but the results have remained controversial. Therefore, we conducted a systematic review of studies to examine the association of PBC with cancer risk by meta-analysis. We searched Pubmed and EMBASE databases before November, 2011, with a restriction to English publications. Studies were included if they reported relative risk estimates with 95% CIs or related data for the association between PBC and cancer risk. Approximately 16300 PBC patients from several countries were included in this analysis. Of 3510 titles identified, 16 publications involving 17 studies which met inclusion criteria, were included in the meta-analysis. Compared with general population, PBC patients had a significantly higher risk of overall cancer (pooled RR, 1.55; 95% CI, 1.28-1.83) and hepatocellular carcinoma (HCC) (pooled RR, 18.80; 95% CI, 10.81-26.79). For stomach and pancreas cancers, one study only examining male patients with PBC, indicated that PBC patients had increased risk of stomach cancer and pancreas cancer, while other studies showed no significant association in mixed-gender patients. Therefore, despite of inconsistent results, the meta-analysis could not be conducted for assessing the association. PBC was not significantly associated with increased risk of other cancers. In conclusion, the present systematic review and meta-analysis demonstrated that PBC is closely associated with a greater risk of overall cancer and HCC, but not with other cancers. The data regarding the association between PBC and risks of several cancers, from too small number of studies, need to be further confirmed in a larger number of studies.