Genetic Susceptibility to Breast Cancer

Breast cancer is the most prevalent cancer among women, annually affecting more than one and half million women worldwide. The risk of breast cancer varies between women, and genetic susceptibility plays an important role in the etiology of the disease. Hereditary breast cancer cases are estimated to account for 10-15% of all breast cancers and BRCA1 and BRCA2 genes, the two major breast cancer susceptibility genes which are routinely screened in hereditary cases, are responsible for only 15% to 20% of the inherited breast cancers. There are dozen more known breast cancer susceptibility genes such as ATM, CDH1, CHEK2, NBN, PALB2, PTEN, STK11, TP53 and RECQL which are estimated to be responsible for another 30-40% of the hereditary breast cancers. Identifying these mutated genes in hereditary breast and ovarian cancer families will have a great impact on reducing the mortality rate associated with breast cancer. By identifying women with genetic mutations, it will be possible to prevent cancers with prophylactic surgery or chemoprevention, or to detect it early using intensified screening. It is also possible that identifying the mutated genes in breast cancer patients could potentially result in better treatments for the patients with implications on health-care system for breast cancer.