against breast cancer is currently in the experimental stageEIGHT FACTS Chapter 15 GeneticBreast cancer can be random (90%) or hereditary (10%) of the timeBRCA-1 and BRCA-2, genetic abnormalities, have been linked with breast cancer development (155)The BRCA-1, an autosomal-dominant gene, is located on chromosome 17. . Autosomal defects are inherited 50% of the time so males inherit these defects too. Prostate cancer has been associated with male inheritance of the BRCA-1 gene. 60-90% of patients with the BRCA-1 gene will develop breast cancer60% of patients with BRCA-1 gene will develop ovarian cancerThe BRCA-2 gene, also an autosomal-dominant gene, is located on chromosome 2Gene defects that may lead to cancer development arise from oncogene production, defects in tumor suppression genes, and the action of mutator genes. (156)Commercial genetic testing for breast cancer associated genes is available. (158)Women with breast cancer are concerned about risks to daughters and sisters. (158)Creation of breast cancer family trees from historical records can be helpful for future risk of occurrenceWomen are concerned about the risk of second breast cancer development for themselves (159)Breast cancer incidence for high-risk women varies according to the type of cancer and the extent of genetic pre-dispositionSurveillance is highly recommended for many high-risk women for breast cancer.Women over 35 with gene mutations in BRCA-1 and BRCA-2 should monitor breast and ovarian cancer developmentSurveillance for genetically predisposed women includearmonthly breast self-examinations, bi-annual or annual physical examinations followed by annual mammography.Tamoxifen taken prophylactically may reduce breast cancer in predisposed women.A small minority of women with genetic predisposition to breast cancer seek prophylactic mastectomy. This surgery has been shown to reduce the risk of breast cancer development by 90%Women with genetic mutat...
