C-reactive protein and risk of ovarian cancer: A systematic review and meta-analysis

BACKGROUND: Although several studies have suggested an association between elevated C-reactive protein (CRP) and ovarian cancer risk, others have yielded contradictory results. To address this issue, we conducted a meta-analysis. METHODS: Studies were identified by searching PubMed and EMBASE up to July 2017 without language restrictions. Six case-control studies and 1 cohort study were included, including 1898 ovarian cancer cases. Pooled risk estimates were generated by using the fixed-effect model or the random-effect model based on the heterogeneity between studies. RESULTS: As our data shown, the combined ORs were 1.04 (95%CI: 0.90–1.21) and 1.34 (95% CI: 1.06–1.70) for the risk in the second and third tertiles of CRP with those in the bottom tertile, respectively. Subgroup analysis showed that with respect to the top tertile of CRP level, the association was significant for studies obtaining CRP from serum (OR=1.99; 95% CI: 1.30–3.07), conducted in the USA (OR = 1.41; 95% CI: 1.15–1.72), using high-sensitivity immunotubidimetric assay (OR = 1.37; 95% CI: 1.14–1.64), using Hs-CRP (OR = 1.46; 95% CI: 1.21–1.75) and with follow-up period longer than 10 years (OR = 1.41; 95% CI: 1.18–1.70). CONCLUSION: Collectively, our findings propose that serum CRP levels may serve as an indicator of ovarian cancer risk. Further studies are needed to definitively identify the role of CRP in the etiology of ovarian cancer.