The number of aberrantly methylated genes and the methylation status of p73 and RARB are related to prognosis in breast cancer patients

MARZESE, DIEGO; GAGO, FRANCISCO; OROZCO, JAVIER; TELLO, OLGA; ROQUÉ, MARÍA; VARGAS ROIG, LAURA

Chicago, Illinois

Congreso; American Society of Clinical Oncology (ASCO) Annual Meeting.; 2011

ASCO

Background: Invasive ductal carcinoma (IDC) is the most frequent type of human breast cancer. Despite sharing a common origin, a great variation is observed among patients´ outcome, which can be explained by their genetic and epigenetic differences. The most commonly reported epigenetic alteration is the aberrant methylation of CpG islands. In previous reports we have shown that the tumor methylation profile (TMP) is specific for each breast cancer patient. Here we evaluate the epigenetic differences between IDCs from patients with good and poor prognosis. Methods: The methylation status of 49 cancer-related regions was studied in seventy patients bearing IDC using the Methyl Specific-MLPA assay. Statistical associations were determined by chi square test and the strength of associations was assessed by Phi and Cramer´s V coefficient. Statistical correlations were established by Pearson´s r and Spearman´s rho coefficient. Results: Tumors with increased number of methylated cancer-related regions correlate with high histological grade (p=0.002) and high proliferation rate (p