Clinicopathological significance of p15 promoter hypermethylation in multiple myeloma: a meta-analysis

Published studies reported that loss of function of the p15(INK4B) gene is caused by hypermethylation; however, whether or not the inactivation is associated with the incidence and clinical significance of multiple myeloma (MM) remains unclear. In this study, we performed a meta-analysis to quantitatively determine the effects of p15 hypermethylation on the incidence of MM. The related research articles in English and Chinese languages were evaluated. The data were extracted and assessed independently. The pooled data were analyzed and odds ratios were calculated and summarized. Sixteen eligible studies were selected for final analysis. We demonstrated that p15 hypermethylation is significantly higher in MM than that in normal bone marrow, as well as monoclonal gammopathy of undetermined significance. However, aberrant p15 hypermethylation was not significantly higher in advanced MM than that in early-stage MM. The results of this study reveal that p15 hypermethylation is correlated with an increased risk in the progression of monoclonal gammopathy of undetermined significance to MM. p15 hypermethylation, which induces the loss of function of the p15 gene, plays a critical role in the early tumorigenesis of MM and serves as a reputable diagnostic marker and potential drug target.