Home Blog BRCA 1 and BRCA Cancer Risks

    BRCA 1 and BRCA Cancer Risks

    SHARE

    Today we will be discussing BRCA1 and BRCA2 mutations in the diagnosed patient.  We will talk about the recommended surveillance schedule, as well as what malignancies are associated with these mutations.

    Most women who are diagnosed, with breast or ovarian cancer, have a sporadic type of malignancy, as opposed to an inherited form of cancer.

    BRCA Gene Mutation Statistics

    While only around 5%-10% of women with breast cancer have BRCA mutations, up to approximately 20% of women with a significant family history of breast cancer, have mutations in the BRCA genes.

    A recent study performed by the NIH showed there are several different types of cancer that increases the risk if a patient has a BRCA1 or BRCA2 mutation present.

    These include breast (both female and male), ovarian, prostate, pancreatic, and melanoma.

    The percentage of increased risk, in a patient with a BRCA1 or BRCA2 mutation, in comparison to the risk in the general population is as listed in the below table:

    BRCA Risk of malignancy
    source: https://www.ncbi.nlm.nih.gov/books/NBK1247/

    Breast Cancer and BRCA Gene Mutation

    The most common associated malignancy in people with BRCA gene mutations is breast cancer. This increased risk ranges from 46%-87% in patients with a BRCA1 mutation, and it 38%-84% increase in patients with a BRCA2 mutation.

    This percentage is increased from the general population risk of breast cancer at 12%.

    The risk of second breast cancer cases in patients with previous breast cancer in the contralateral breast is:

    • BRCA1 Mutation
      • Diagnosed at age 25-29 years with their first breast cancer
        • 5-year risk = 16%
        • 10-year risk = 29%
      • Diagnosed at age 50-54 years with their first breast cancer
        • 5-year risk = 6%
        • 10-year risk = 11.7%
    • BRCA2 Mutation
      • Diagnosed at age 25-29 years with their first breast cancer
        • 5-year risk = 14.6%
        • 10-year risk = 26.6%
      • Diagnosed at age 50-54 years with their first breast cancer
        • 5-year risk = 5.3%
        • 10-year risk = 10.4%

    Ovarian Cancer and BRCA Gene Mutation

    The second most common type of cancer which affects patients with BRCA mutations is ovarian cancer.

    The malignancy risk of ovarian cancer in patients with a BRCA1 mutation is from 39%-63%. In patients with the BRCA2 mutation, there is a 16.5%-27% risk of ovarian cancer.

    The general population risk of ovarian cancer ranges from 1% to 2% in comparison.

    Other Cancers Associated with BRCA Gene Mutation

    There is a documented increased risk of pancreatic cancer in patients with BRCA1 and BRCA2 mutations. In patients with BRCA1 mutation, the risk of pancreatic malignancy is 1% to 3%. And in those individuals with a BRCA2 mutation, the risk of malignancy is 2% to 7%.

    The general population’s average risk of pancreatic malignancy is around 0.5%.

    BRCA1 and BRCA2 mutations generally are known to cause malignancies in females, but there is a known increase in the risk of male breast and prostate cancers.

    In the general population, the risk of breast cancers in males is around 0.1%. In men who have a known BRCA1 mutation, there is a 1.2% risk of breast cancer and those with a BRCA2 mutation the risk is up to 8.9%.

    In males with a known BRCA1 mutation, the risk of prostate cancer has been shown to be 8.6% by age 65 years. In those with the BRCA2 mutation, the risk of prostate cancer is 15% by age 65, and an overall 20% lifetime risk.

    The risk of acquiring prostate cancer in the general population is 6% through age 69 years, in comparison.

    Lastly, there have been studies that have shown an increased risk of melanoma to BRCA2 gene mutation. This includes both melanoma of the skin as well as the ocular variant.

    As you can see, there are several types of malignancies that are potentially predisposed to patients with BRCA1 and BRCA2 gene mutations.

    Surveillance for BRCA 1 and BRCA 2 Gene Mutation Carriers

    In women, breast cancer awareness should begin at 18 years of age. Females should become familiar with their breasts and should report changes to their healthcare provider if noticed.

    It should be recommended to female patients that self-breast exam is most informative when performed at the end of menses.

    Clinical breast exam should begin at age 25 and occur every 6 to 12 months.

    Breast screening recommendations vary based on age:

    Age 25 to 29 years: Annual breast MRI (performed days 7-15 of menstrual cycle) or mammogram screening (only if breast MRI is unavailable)

    Age 30-75 years: Annual mammography and breast MRI screening alternating every six months

    Age >75 years: Management should be considered on an individual basis

    Prophylactic risk-reducing mastectomy should be considered as treatment as well.

    Regarding monitoring for ovarian cancer, patients should consider the risk-reducing salpingo-oophorectomy, ideally between the ages of 35 and 40 years, upon completion of childbearing.

    Based on updated data, BRCA2 carriers may be able to delay this procedure until the ages of 40 and 45 years. 

    This should be individualized, with the earliest age of onset of ovarian cancer in the family, and if bilateral prophylactic mastectomy was previously pursued.

    The psychosocial, social, and quality of life aspects of an individual undergoing prophylactic mastectomy and/or salpingo-oophorectomy needs to be considered.  Larger multidisciplinary facilities will often offer preoperative reproductive counseling before the procedures are performed.

    For patients not undergoing risk-reducing salpingo-oophorectomy, concurrent transvaginal ultrasound (preferably days 1-10 of the menstrual cycle) and CA-125 (preferably after day five of the menstrual cycle), should be completed every six months.

    Ovarian cancer screening should begin at the age of 30 years or 5-10 years before the earliest diagnosis of ovarian cancer in the family.

    Management Options For BRCA Gene Mutations

    In patients who choose not to have prophylactic mastectomy or salpingo-oophorectomy, or those who are carriers with a history of breast cancer, chemoprevention options should be discussed.

    These include Tamoxifen, Raloxifene, oral contraceptives, as well as platinum agents such as cisplatin, carboplatin, and PARP inhibitors such as Olaparib.

    Tamoxifen should not be used in men unless their overall risk of breast cancer is high.

    Even though chemoprevention is an option, it is shown to be less effective than prophylactic mastectomy and salpingo-oophorectomy.

    For melanoma, there are no specific guidelines for surveillance that currently exist.

    A baseline skin survey is recommended for consideration with self-awareness of any skin changes.

    Screening for pancreatic cancer may be individualized based on malignancy observed in a patient’s family history. However, there are currently no specific guidelines for surveillance.

    Surveillance for BRCA Gene Mutations In Men 

    For men, monthly self-breast exam training and education is recommended to begin 35 years of age.

    Additionally, clinical breast exams are recommended to begin at age 35 years of age, and should take place every 6 to 12 months.

    A baseline mammogram should begin at age 40, and annual mammograms may be considered on an individual basis.

    Beginning at age 45, males with BRCA2 mutations should start prostate cancer screening with PSA levels. Men with BRCA1 gene mutation can consider this testing as well for prostate cancer screening. 

    There is no evidence that performing digital rectal exam improves survival in cases of prostate cancer.

    In patients with BRCA gene mutations, who suffer from prostate cancer, the treatment is the same for patients who are diagnosed with sporadic prostate cancer.

    However, because prostate cancer associated with BRCA mutations is often more aggressive, treatment with surgery or radiation typically is recommended as opposed to active surveillance.

    There is no data or recommendations on the use of 5-alpha-reductase inhibitors as chemoprevention in patients with BRCA mutation associated prostate malignancy.

    No specific guidelines exist for melanoma pancreatic cancer surveillance in males.

    A baseline skin survey as above with females is recommended for males as well.

    Pancreatic cancer screening may be individualized based on cancers observed in the family.

    Final Thoughts on BRCA Gene Mutation

    Regardless of gender, education for signs and symptoms of cancer should be pursued.

    For patients of reproductive age, advice should be sought regarding risk to offspring and the possibilities of prenatal diagnosis, gamete donation, and preimplantation genetic diagnosis. 

    Additionally, the increased risk of rare autosomal recessive conditions for individuals inheriting two of the same cancer genes should be discussed.

    Resources

    • NCBI. BRCA1- and BRCA2-Associated Hereditary Breast and Ovarian Cancer. https://www.ncbi.nlm.nih.gov/books/NBK1247/. Accessed: 10/23/17.
    • UpToDate. Screening for Prostate Cancer. Accessed 10/23/17.
    • UpToDate. Management of Patients at High Risk for Breast and Ovarian Cancer.  Accessed: 10/23/17.
    • UpToDate. Prevalence of BRCA1 and BRCA2 Mutations and Associated Cancer Risks. Accessed: 10/23/17.
    • AAFP. Ovarian Cancer: An Overview. Accessed: 10/24/17.
    SHARE
    Previous articleIrritable Bowel Syndrome: A Clinical Review
    Next articleTackling low back pain
    Clay Walker
    Clay Walker is a board-certified physician assistant practicing in family medicine and urgent care in rural southern Illinois. He is a graduate of Southern Illinois University School of Medicine Physician Assistant Program - class of 2016. Prior to going to PA school, Clay worked as a histology technician in southern Illinois.  From an early age, he has been interested in medicine. Clay was diagnosed as a type 1 diabetic in the first grade. He began learning about his condition and teaching others about T1DM; since then, he began to have a passion to learn medicine and make a difference in the lives of others. In his free time, Clay enjoys watching sports and going to sporting events, specifically the Chicago Cubs and Philadelphia Eagles.