TY - CHAP M1 - Book, Section TI - Breast Cancer A1 - Couch, Fergus J. A1 - Weber, Barbara L. A2 - Valle, David L. A2 - Antonarakis, Stylianos A2 - Ballabio, Andrea A2 - Beaudet, Arthur L. A2 - Mitchell, Grant A. PY - 2019 T2 - The Online Metabolic and Molecular Bases of Inherited Disease AB - Breast cancer is the most frequently diagnosed cancer in Western women and the leading cause of death in U.S. women aged 40 to 55. Breast cancer is heterogeneous in its clinical, genetic, and biochemical profile. The large majority of affected women present with a breast mass or mammographic abnormality as the only clinically detectable manifestation of disease, yet approximately 30 percent of women diagnosed with breast cancer go on to develop metastatic disease that ultimately is fatal.Numerous risk factors for the development of breast cancer have been identified. Family history suggesting an inherited component in the development of some breast cancers is one of the strongest known risk factors. It is estimated that 15 to 20 percent of women with breast cancer have a family history of the disease, with approximately 5 percent of all breast cancers attributable to dominant susceptibility alleles. Two major breast cancer susceptibility genes (BRCA1 and BRCA2) have been identified; others are being actively sought.Breast cancer may present in a preinvasive form or an invasive form. Treatment depends on the stage at diagnosis, patient age at the time of diagnosis, and the presence or absence of the estrogen receptor in tumor cells. The prognosis is largely dependent on the stage at diagnosis.BRCA1 is a highly penetrant breast cancer susceptibility gene on chromosome 17q21 that is thought to account for 20 to 30 percent of inherited breast cancers. Families with germ-line mutations in BRCA1 have an autosomal dominant inheritance pattern of breast cancer as well as an increased incidence of ovarian cancer. The mutation spectrum of BRCA1 is well defined, and functional links to transcription regulation, cellular response to DNA damage, and development are becoming evident.BRCA2 is a highly penetrant breast cancer susceptibility gene on chromosome 13q12–13 that is thought to account for 10 to 20 percent of inherited breast cancers. Families with germ-line mutations in BRCA2 also have an autosomal dominant inheritance pattern of breast cancer, an increased incidence of ovarian cancer that is less striking that that with BRCA1, and an increased incidence of male breast cancer. The mutation spectrum of BRCA2 is well defined, and functional links also have been made to transcription regulation, cellular response to DNA damage, and development.Sporadic breast cancers have been studied extensively for molecular changes that may provide clues to etiology, prognosis, and improved treatment approaches. Growth factors and their receptors, intracellular signaling molecules, regulators of cell cycling, adhesion molecules, and proteases have all been shown to be altered in sporadic breast cancer. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/10/05 UR - ommbid.mhmedical.com/content.aspx?aid=1181416445 ER -