Este trabajo fue posible debido al apoyo del Consejo Na-cional de Ciencia y Tecnología (CONCYTEC), contrato 359-2006-CONCYTEC-OAJ y de la Facultad de Medicina de U. de San Martín de Porres (proyectos E10012007006, E10012009013).

Universidad de San Martin de Porres Funds, Lima, Per (Project number E20012003005), Consejo Nacional de Ciencia y Tecnolog a Per (CONCYTEC).

OAJ-2003

Background: Promoter hypermethylation is one of the enabling mechanisms of hallmarks of cancer. Tumor suppressor genes like RARB and GSTP1 have been reported as hypermethylated in breast cancer tumors compared with normal tissues in several populations. This case–control study aimed to determine the association between the promoter methylation ratio (PMR) of RARB and GSTP1 genes (separately and as a group) with breast cancer and its clinical-pathological variables in Peruvian patients, using a liquid biopsy approach. Methods: A total of 58 breast cancer patients and 58 healthy controls, matched by age, participated in the study. We exacted cell-free DNA (cfDNA) from blood plasma and converted it by bisulfite salts. Methylight PCR was performed to obtain the PMR value of the studied genes. We determined the association between PMR and breast cancer, in addition to other clinicopathologi...