A meta-analysis on major risk factors of multiple primary cutaneous melanomas

Background. Identifying multiple primary melano ma (MPM) risk factors is an important step towards detecting secondary primaries at an early stage and optimizing follow-up of melanoma patients. Therefore, we examined the risk factors for MPM versus single primary melanomas (SPM) in a meta-analysis. Methods. Published literature comparing risk factors for MPM versus SPM up until May 13, 2013 were retrieved from Embase and MEDLINE databases. Effect sizes were aggregated and analyzed using random effects models (REM) using Bayesian methods. Results. 16 articles comparing risk factors between MPM versus SPM, comprising of 2442 MPM and 24.895 SPM individuals were included. Positive family history (OR 2.0,95% HPD:1.6-2.7), presence of dysplastic nevi (OR 4.4,95% HPD: 2.6-8.9) and light hair color (OR 1.4,95% HPD:1.1-1.7) were shown to be significantly linked with MPM. Bayesian estimates of other factors, including benign nevi count, sunburn history, freckles and phototype were not significantly raised. Limitations. Heterogeneity between studies and the small number of eligible papers limited our meta-analysis. Conclusion. This meta-analysis confirms that a positive family history, presence of dysplastic nevi and light hair color correlate with higher risk for developing MPM. Patients with these characteristics should be carefully monitored.