Family History of Breast Cancer Raises Risks

If you have had a strong family history of breast cancer, even if you do not carry the genes yourself, you might want to pay close attention to this subject as it could affect you more than you know. Women that have had a strong family history of breast cancer that do not have the genes with increased risk for the disease have a fourfold greater chance of developing it than the average woman.

Senior author of the study, Steven Narod, M.D. from the University of Toronto, said that the findings of the most recent study could help doctors detect breast cancer earlier in women of high-risk and lead to more and earlier preventive treatments. Women that have several blood relatives who have breast cancer have been known for years to be at a higher risk themselves. "Today, when we see families like this, we will be able to offer them better advice about their actual risk. It is very clear that the risk is going to be high enough that we need to discuss options, such as getting a breast MRI for screening and chemoprevention with raloxifene or tamoxifen. Our hope for the future is to be able to prevent or detect breast cancer soon enough to stop patients from dying."

The new findings also suggest that additional hormones, genes, and other factors, perhaps environmental, are also responsible for the cause of breast cancer. This seems apparent from the study’s finding that women that have a strong family history were still at a higher risk of developing breast cancer even if they did not have BRCA gene mutations.

Kelly Metcalfe, R.N., Ph.D., who is also from the University of Toronto, said that only 5% of women that have breast cancer have a BRCA mutation, and this has been making it very difficult to counsel women that do not have that mutation about their risk of breast cancer. :For women that we do find a mutation, she has and 80% risk of developing breast cancer. For the women that have had a significant family history of breast cancer, that do not have the BRCA 1-2 mutation, we can now say that she has a 40% chance of getting breast cancer. This data can be compared to a 10% risk that a woman has for breast cancer in the general population."

So what are the options for women that have a family history of breast cancer? The “take-away” message from this study, in which 1,492 women that have first-degree breast cancer relatives were studied, is this, Metcalf stated: “Having a BRCA mutation is the greatest risk factor for developing breast cancer. However, we still need to be very aware of a woman’s family history of breast cancer, even without a mutation.” Narod adds that despite a negative test for the BRCA mutations, women are still not cleared.

He says that he could recommend that women without the BRCA mutations who have three or more relatives that have breast cancer should undergo MRI screenings and consider taking a medication called tamoxifen. The findings of this study do not call for preventative surgery—which is removal of the breasts—but he does say that some women may wish to consider that option.

He adds that we have to take tamoxifen more seriously as a society as a preventative measure for breast cancer. This medication can reduce the risk of breast cancer from 40% to 20% which are pretty dramatic figures. Any woman that has a 40% risk of breast cancer should seriously consider this option. However, researchers say that they are no ready yet to recommend that all women with a family history of breast cancer get tested for the BRCA genes. This is considered a personal decision whether or not to have genetic testing done, Metcalfe states. However, for women that do have a family history of breast cancer, genetic testing can offer information about their own risk of developing ovarian or breast cancer, and if the woman is found to have the BRCA genes, options are now available to significantly reduce their risk of breast cancer.

The director of breast and gynecologic cancer for the American Cancer Society, Debbie Saslow, Ph.D., said that it is important that women with a family history of breast cancer who have no genetic markers to know that they are still at an increased risk that is very significant. She also says that the study suggests that other genes, that are yet to be identified, could put women at a higher risk for breast cancer.

Women that have a family history of breast cancer should start screening at the age of 30 and make sure that their physicians know that they have relatives who have been diagnosed.

Genetic testing is not for everyone, but counseling can help women to make an informed decision. The American Cancer Society says many clinical studies have shown that raloxifene and tamoxifen could reduce that risk of breast cancer in women that are high risk.