Prevalence of p16 Methylation and Prognostic Factors in Plasma Cell Myeloma at a Single Institution in Korea

BACKGROUND The primary purpose of this study was to investigate the prevalence and characteristics of p16 methylation and determine the prognostic implications of the clinical data, hematologic data, and p16 methylation changes in plasma cell myeloma (PCM). METHODS We reviewed clinical characteristics and results of laboratory tests and investigated the response to combination chemotherapy and survival time. DNA methylation of the p16 gene was tested by methylation-specific PCR. Clinical significance was evaluated. RESULTS A total of 103 patients were enrolled in this study. The median patient age was 59.0 yr at diagnosis and the male to female ratio was 1.15:1. According to the International Staging System (ISS), patients were diagnosed as stage: I (N=17, 16.5%), II (N=41, 39.8%), III (N=39, 37.9%), or not classified (N=6). Forty-five (43.7%) patients and 36 (35.0%) patients showed abnormal karyotype and complex karyotype, respectively, on the chromosome study. The p16 methylation was observed in 39 (37.9%) of 103 patients, but there was no significant association between p16 methylation status and other clinical or laboratory factors and survival outcome. Male gender, albumin, and complex karyotype were independent prognostic factors for overall survival according to multivariate analysis (P<0.05). CONCLUSIONS The male gender, low serum albumin level, and complex karyotype were independent poor prognostic factors for PCM. p16 methylation was relatively common in PCM, but did not influence the survival outcome.