BREAST CANCER AND THE " DISCOVERY " OF BRCA GENES Breast cancer

Abstract

Breast cancer is the most common form of cancer and the second major cause of death among American women today. In the general population, the risk of developing breast cancer increases with age (80% of cases occur in women older than 50), medical history and hormonal influences (excess estrogen plays a role in stimulating breast cell growth), among other variables. Three to five percent of the cases of invasive breast cancer diagnosed in 2001 were associated with mutations within BRCA1 or BRCA2, two breast cancer susceptibility genes identified in 1994. Studies on a related protein in yeast revealed that the BRCA genes participate in repairing radiation induced breaks in DNA. Mutations in these genes might disable this mechanism, leading to more errors in DNA replication and eventually to cancerous growth. In a way, this would make us age faster in terms of DNA replication capacity and thus render us more prone to developing breast cancer earlier than normal. Therefore, individuals who carry certain mutations in either BRCA gene are at an increased risk of being diagnosed with the disease. These mutations are thought to account for 80% of hereditary breast cancers. Despite certain gene testing capacity the best means to reduce mortality at a national rate is still through early detection and traditional preventive mechanisms, since screening an entire population for BRCA cancer predisposing mutations is not yet recommended. However, with recent developments and the planning of future research, we already face tough decisions regarding the field of cancer and genomics.