Sarcoidosis and Cancer Risk : Systematic Review and Meta-analysis of Observational Studies

BACKGROUNDAn increased cancer risk in patients with sarcoidosis has been suggested, although results are conflicting in a number of case-control and cohort studies. We conducted a systematic review of all available data and performed a meta-analysis to better define and quantify the association between sarcoidosis and cancer.METHODSWe searched Medline and Embase for all original articles on cancer and sarcoidosis published up to January 2013. Two independent authors reviewed all titles/abstracts to identify studies according to predefined selection criteria. We derived summary estimates using a random-effects model and reported them as relative risk (RR). Publication bias was evaluated using a funnel plot and was quantified by the Egger test.RESULTSSixteen original studies, involving > 25,000 patients, were included in the present review. The summary RR to develop all invasive cancers was 1.19 (95% CI, 1.07-1.32). The results for selected cancer sites indicated a significantly increased risk of skin (RR, 2.00; 95% CI, 1.69-2.36), hematopoietic (RR, 1.92; 95% CI, 1.41-2.62), upper digestive tract (RR, 1.73; 95% CI, 1.07-2.79), kidney (RR, 1.55; 95% CI, 1.21-1.99), liver (RR, 1.79; 95% CI, 1.03-3.11), and colorectal cancers (RR, 1.33; 95% CI, 1.07-1.67). There was no evidence of publication bias for all cancers (P= .9), nor for any specific cancer site.CONCLUSIONSThe present meta-analysis suggests a significant, though moderate, association between sarcoidosis and malignancy.