MDM2 promoter polymorphism del1518 (rs3730485) and its impact on endometrial and ovarian cancer risk

Liv B. Gansmo, Merete Bjørnslett, Mari Kyllesø Halle, Helga B. Salvesen, Pål Romundstad, Kristian Hveem, Lars Vatten, Anne Dørum, Per E. Lønning, Stian Knappskog

The del1518 (rs3730485) polymorphism is an in/del variant in the MDM2 promoter P1. The variant is in complete linkage disequilibrium with MDM2 SNP309 (rs2279744) and has previously been found associated with an increased risk of colon cancer. In this study we assessed the impact of MDM2 del1518 on risk of ovarian and endometrial cancer. Here, we genotyped del1518 in two large hospital-based series of patients diagnosed with ovarian (n = 1,385) or endometrial (n = 1,404) cancer and performed risk estimations as compared to the genotype distribution among 1,872 healthy female controls. In overall analysis we observed no association between del1518 and risk of either ovarian or endometrial cancer. However, stratifying according to SNP309 status, we found the del1518 variant to be associated with a reduced risk of endometrial cancer among individuals carrying the SNP309TT genotype both in the dominant (OR = 0.64; 95% CI = 0.45 - 0.90) and the recessive model (OR = 0.80; 95% CI = 0.65 - 1.00). No such association was observed for ovarian cancer risk. We found the MDM2 del1518 del variant to be associated with reduced risk of endometrial cancer among individuals carrying the MDM2 SNP309TT genotype.