Hereditary Breast and Ovarian Cancer
Hereditary breast and ovarian cancer (HBOC) syndrome is an inherited disorder that is mainly associated with tumors of the breasts and ovaries. Other malignancies in HBOC families can include melanoma, pancreatic, and prostate cancer. In comparison to sporadic breast and ovarian cancers, HBOC syndrome tends to occur at an earlier age (i.e. < 50 years). Tumors often occur bilaterally, consist of multiple affected family members, including males with breast cancer, and occur with a higher predisposition in specific ethnicities, such as the Ashkenazi Jewish population (Petrucelli et al. 2011; ncbi.nlm.nih.gov/books/NBK1247; Pruthi et al. PubMed ID: 21123638). Identifying individuals with a high risk for developing HBOC may allow for early detection of tumor formation and allow for prophylactic mastectomy and/or oophorectomy or other treatments (Smith, J . 2012; PubMed ID: 23050669). Breast and ovarian cancers can show a familial inheritance due to shared environment or inherited genes of low penetrance, which confer a moderate risk (Berliner et al., J Genet Counsel. 2013; 22:155-163). In addition, approximately 5-10% of breast and 10-15% of ovarian cancer cases are the result of genetic predisposition due to gene specific mutations that significantly increase an individual's risk of developing these cancers (Marchina et al. 2010. PubMed ID: 21042765). HBOC syndrome is mainly due to mutations in the BRCA1 and BRCA2 genes; however, pathogenic variants have also been found in other genes. This was noted because higher incidences of breast and/or ovarian cancer have been observed in several syndromes, albeit with different cancer spectrums, including Li-Fraumeni syndrome, Cowden syndrome, Peutz-Jeghers syndrome, and Fanconi Anemia caused by mutations in TP53, PTEN, STK11, and the FANC gene family, respectively.
For patients with cancer, treatment options and survival are related to stage. Early detection yields better outcomes and significantly decreased mortality rate (National Cancer Institute: Cancer Screening; cancer.gov). Prophylactic mastectomy/oophorectomy and tamoxifen have proven to be effective breast/ovarian cancer risk-reducing options for patients.
Risk-reducing salpingo-oophorectomy has been widely adopted as a key component of breast and gynecologic cancer risk reduction for patients with HBOC and has been associated with an 85% risk reduction in gynecologic cancer and a 72% risk reduction in breast cancer (Kauff et al. 2008. PubMed ID: 18268356). Bilateral prophylactic mastectomy has yielded a reduced risk of 89.5% ((Hartmann et al. 1999. PubMed ID: 9887158).
Treatment with tamoxifen prophylaxis has a reported 49% reduction in breast cancer (Petrucelli et al. 2011; ncbi.nlm.nih.gov/books/NBK1247). Tamoxifen use also significantly reduces the occurrence of contralateral breast cancer endpoints (Pierce et al. 2006. PubMed ID: 16636335). This treatment has been proven to be more effective in younger women, making an early diagnosis critical to avoid morbidity/mortality (Gail et al. 1999. PubMed ID: 10547390).
Screening and Early Detection
Early detection of cancer is the most important aspect in ensuring a favorable prognosis (Schreer & Lutges 2005). Breast cancers that are found because they are causing symptoms tend to be larger and are more likely to have already spread beyond the breast, making early, continuous screening essential (American Cancer Society. 2013; cancer.org). However, breast cancers found during screening exams are more likely to be smaller and still confined to the breast increasing treatment options and improving quality of life (American Cancer Society. 2013; cancer.org). Patients diagnosed with HBOC mutations should receive MRI screening as it has proven to be more effective in early detection of tumors and should also begin screening at a younger age (National Cancer Institute; cancer.gov). Additional cancers can also be associated with HBOC, making awareness key for implementation of the proper screening techniques to ensure a higher quality of life and favorable prognosis (National Cancer Institute; cancer.gov).
For more information on HBOC testing, please see our full Test Description.
This article is a summary of information that has been reported in the biomedical research literature. It is not medical advice for patients. All disease treatments should be under the direction of a qualified healthcare provider.
Last Updated: 4/10/2017