title: Can we prevent BRCA1-associated breast cancer by RANKL inhibition?
abstract: BRCA1 mutation carriers face a high lifetime risk of breast cancer, estimated at 60 % compared to 10 % in the general population. BRCA1 breast cancers typically have an aggressive course (i.e., high-grade, triple-negative) and are associated with a poor prognosis. At present, primary prevention is limited to prophylactic removal of the unaffected breasts. Effective chemopreventive strategies are not yet available. Emerging evidence suggests that BRCA1 mutation carriers have high circulating levels of progesterone which may play a role in their susceptibility to breast cancer. Recently, the RANK/RANKL system was found to be dysregulated in women with a BRCA1 mutation. Mutation carriers had significantly lower endogenous levels of osteoprotegerin (OPG) than women without a BRCA1 mutation. OPG is an endogenous decoy receptor for RANKL and inhibits RANKL-mediated signaling. RANKL binds to RANK on mammary epithelial cells and stimulates their proliferation and maturation. Low OPG levels may contribute to mammary tumorigenesis through increased proliferation and may explain in part the increased breast cancer risk in BRCA1 mutation carriers. Denosumab is an anti-RANKL monoclonal antibody which is approved to treat osteoporosis and to prevent skeletal damage caused by bone metastases. The emerging role of aberrant RANK-signaling in BRCA1 tumorigenesis suggests that targeting of RANKL may prevent breast cancer among women with germline BRCA1 mutations. Clinical investigations of denosumab are warranted and may lead to a novel chemopreventive approach for breast cancer for high-risk women.
authors: Women's College Research Institute, Women's College Hospital, 76 Grenville St., 6th Floor, Toronto, ON, M5S 1B2, Canada. joanne.kotsopoulos@wchospital.ca.|Dalla Lana School of Public Health, University of Toronto, 155 College Street Health Science Building, 6th Floor, Toronto, ON, Canada. joanne.kotsopoulos@wchospital.ca.
authors: Joanne
authors: J
authors: Kotsopoulos
authors: Department of Obstetrics and Gynecology and Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria.
authors: Christian
authors: C
authors: Singer
authors: Women's College Research Institute, Women's College Hospital, 76 Grenville St., 6th Floor, Toronto, ON, M5S 1B2, Canada.|Dalla Lana School of Public Health, University of Toronto, 155 College Street Health Science Building, 6th Floor, Toronto, ON, Canada.
authors: Steven A
authors: SA
authors: Narod
mesh_terms: D019313:BRCA1 Protein / Q000235:genetics* / Q000378:metabolism; D015415:Biomarkers; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000517:prevention & control*; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism; D018890:Chemoprevention / Q000379:methods; D019468:Disease Management; D005260:Female; D006579:Heterozygote; D006801:Humans; D009154:Mutation; D053244:Osteoprotegerin / Q000235:genetics / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism; D053245:RANK Ligand / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D019313:BRCA1 Protein; D015415:Biomarkers; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D011374:Progesterone
keywords: BRCA; Breast cancer; Denosumab; Prevention; RANKL