Male BRCA2 Carriers Have Increased Lifetime Risk of Breast Cancer

Men who carry the BRCA2 genetic mutation have a 7.1% chance of developing breast cancer by age 70 and an 8.6% chance of developing the disease by age 80, according to the results of a study published early online in the Journal of Medical Genetics.[1]

Inherited mutations in two genes—BRCA1 and BRCA2—have been found to greatly increase the lifetime risk of developing breast cancer (as well as ovarian cancer in women). Alterations in these genes can be passed down through either the mother’s or the father’s side of the family. Research is ongoing to determine the level of risk presented by these genetic mutations; however, very few studies have focused on male BRCA carriers.

In only the fourth study to do so, researchers from the UK assessed the lifetime risk of breast cancer among men with the BRCA2 mutation. Previous studies have suggested that the BRCA2 mutation places men at higher risk of breast cancer than the BRCA1 mutation.

Using a database that included all male first-degree relatives of BRCA2 carriers over the age of 20, the researchers identified 321 families with proven mutations and 905 male first-degree relatives of proven BRCA2 carriers. Performing a retrospective and prospective analysis of the data, the researchers ascertained that the risk of male BRCA2 carriers developing breast cancer by age 70 was 7.1% and by age 80 was 8.6%.

The researchers concluded that this risk was sufficient to warrant increased awareness about breast cancer among men in BRCA2 families.

Reference:

[1] Evans DG, Susnerwala I, Dawson J, et al. Risk of breast cancer in male BRCA2 carriers. Journal of Medical Genetics [early online publication]. June 28, 2010.

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Screening Radiation Exposure May Increase Breast Cancer Risk in Some BRCA Mutation Carriers

Radiation exposure from x-rays, mammograms, and other diagnostic tests prior to age 30 may increase the risk of breast cancer in women who carry BRCA1 or BRCA2 mutations, according to the results of a large, retrospective cohort study published in the British Medical Journal. ?

Inherited mutations in two genes—BRCA1 and BRCA2—have been found to greatly increase the lifetime risk of developing breast and ovarian cancer. Mutations in these genes can be passed down through either the mother’s or the father’s side of the family.?

A mammogram is an X-ray of the breast. Screening mammography is performed in a woman without breast symptoms in order to detect breast cancer at an early stage when it is most easily treated. Currently, mammography is the most reliable tool for screening the general population for breast cancer and may even reduce the risk of death from breast cancer (due to early detection). Mammograms are most often used in women over the age of 40; however, women who carry BRCA mutations are considered high-risk and may benefit from earlier and more frequent screening. This earlier screening can come with the added risk of increased radiation exposure—and exposure to ionizing radiation, especially when it occurs at an early age, is an established risk factor for breast cancer.? ?

To examine the relationship between radiation exposure and breast cancer risk among BRCA1/2 mutation carriers, researchers from Europe followed nearly 2,000 women over age 18 with a BRCA1 or BRCA2 mutation. The women reported their history of procedures—such as x-rays or mammograms—that involved radiation to the chest or shoulders. The researchers then used this information to estimate the cumulative dose of radiation to the breast for each woman and compared this against confirmed breast cancer diagnoses among the women. ?

When compared with no exposure, any exposure to chest radiation prior to age 30 was associated with almost double the risk of breast cancer in BRCA1/2 mutation carriers. Exposure prior to age 20 was associated with a 62 percent increased risk. Women who received the highest doses or radiation prior to age 30 had almost four times the increased risk. In contrast, there was no evidence of an increased risk of breast cancer associated with exposure after age 30. ?

The researchers concluded that exposure to diagnostic radiation before age 30 among carriers of BRCA1/2 mutations was associated with an increased risk of breast cancer. What’s more—the increased risk of breast cancer was observed at radiation doses considerably lower than those associated with an increased risk among other populations. ?

Because women with BRCA1/2 mutations have an increased risk of developing breast cancer, some guidelines recommend earlier screening; however, the results of this study may indicate that BRCA1/2 carriers under age 30 might benefit from surveillance that uses non-ionizing radiation imaging, such as magnetic resonance imaging (MRI).?

Reference:?

Pijpe A, Andrieu N, Easton DF, et al. Exposure to diagnostic radiation and risk of breast cancer among carriers of BRCA1/2 mutations: retrospective cohort study (GENE-RAD-RISK). British Medical Journal. 2012; 2012;345:e5660?

Posted October 2, 2012

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Hormone Replacement Therapy after Ovary Removal May be Safe for BRCA1/BRCA2 Carriers

For women with BRCA1 or BRCA2 gene mutations, use of hormone replacement therapy after preventive removal of the ovaries and fallopian tubes does not appear to increase the risk of breast cancer. These results were presented at the 2011 annual meeting of the American Society of Clinical Oncology.???

Inherited mutations in two genes—BRCA1 and BRCA2—have been found to greatly increase the lifetime risk of developing breast and ovarian cancer. Mutations in these genes can be passed down through either the mother’s or the father’s side of the family.??

Options to manage this increased cancer risk include regular cancer screening, chemoprevention (use of medications to reduce risk), or preventive surgery (surgery to remove the breasts and/or ovaries before cancer is diagnosed).?

When performed by the time a woman is in her mid-30s or early 40s, preventive removal of the ovaries can substantially reduce the risk of both ovarian cancer and breast cancer. This reduction in cancer risk, however, comes at the cost of an early menopause and symptoms such as hot flashes, sleep disturbances, and vaginal dryness.??

Hormone replacement therapy (HRT) can effectively manage these symptoms, but it’s been uncertain whether this is safe for women with BRCA1/BRCA2 mutations. Studies in women without these mutations have indicated the combined (estrogen plus progestin) hormone therapy increases the risk of breast cancer.?

To evaluate the risk of breast cancer among BRCA1/BRCA2 carriers who have undergone preventive removal of their ovaries and fallopian tubes, researchers collected information from 795 women with a BRCA1 mutation and 504 women with a BRCA2 mutation. ?

????After ovary removal, breast cancer was diagnosed in 14% of the women who took HRT and 12% of the women who did not take HRT. This difference between groups was not statistically significant, suggesting that it could have occurred by chance alone. By comparison, risk of breast cancer was 22% among women who did not have their ovaries removed and did not take HRT.??

These results suggest that short-term use of HRT to manage menopausal symptoms may be an option for BRCA1/BRCA2 carriers who have had their ovaries removed. HRT did not significantly increase the risk of breast cancer in this population.????

Reference: Domchek SM, Friebl T, Neuhausen SL et al. Is hormone replacement therapy (HRT) following risk-reducing salpingo-oophorectomy (RRSO) in BRCA1 (B1) and BRCA2 (B2)-mutation carriers associated with an increased risk of breast cancer? Paper presented at: 2011 Annual Meeting of the American Society of Clinical Oncology; June 3-7, 2011; Chicago, IL. Abstract 1501.?

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