RESUMEN
Breast cancer is the leading cancer among females. There is a critical need for improved molecular biomarkers that are diagnostic, prognostic and also capable of predicting the progression of benign high-risk lesions to invasive carcinoma. RAS association domain family protein 1A [RASSF1A] gene, is a biologically significant cancer suppressor gene, it is normally unmethylated. It has been chosen to study its methylation status among malignant [50] and benign [40] breast lesions using methylation-specific polymerase chain reaction [MS-PCR]. The relation between the methylation status of RASSF1A gene and different clinicopatho-logical factors data in breast cancer was determined. The current results showed a significant difference between malignant and benign group as regard the methylation status of RASSF1A gene. The methylation of RASSF1A gene was higher in the malignant breast lesions. Considering the relation between RASSF1A hypermethylation and differtent clinicopathological factors, no significant association relation was detected except with late tumor grade, late tumor stage and negative estrogen receptor status. The previous findings indicate that the methylation of RASSF1A gene may be used as a diagnostic or/and prognostic biomarker for breast cancer