The age at which breast cancer is diagnosed in families with an abnormal breast cancer gene (BRCA1 or BRCA2) was nearly 8 years earlier in the younger generation compared to the older generation according to a new study. The results were presented at the 2009 ASCO Breast Cancer Symposium.
Women with an abnormal BRCA1 or BRCA2 gene have up to a 60% risk of developing breast cancer by age 70. Their risk of ovarian cancer also is higher than average. Abnormal BRCA1 and BRCA2 genes are found in 5% to 10% of all breast cancer cases in the United States.
In this study, researchers identified 106 families in which close relatives from successive generations had an abnormal BRCA1 or BRCA2 gene and were diagnosed with a BRCA-related cancer (mostly breast cancer). More than 300 women from these families had been diagnosed with cancer.
The researchers found that breast cancer was diagnosed earlier in members of the younger generation compared to members of the older generation, no matter when the women were born. For example, some younger generation women were born in the 1950s and their average age at diagnosis was 43.5. Their older generation relatives were diagnosed at an average age of 50 -- a difference of 6.5 years. Younger generation women born in the 1970s (the youngest women in this study) were diagnosed at an average age of 31, compared to an average age of 44.5 for their older generation relatives -- a difference of 12.5 years.
The researchers aren't sure what's causing this trend of younger diagnosis. Two scenarios are likely contributing to the trend:
- greater awareness
- less than optimal lifestyle choices
Each year, more people learn about the link between breast cancer risk and abnormal BRCA1 and BRCA2 genes. At the same time, doctors promote more aggressive breast cancer screening in anyone with a known abnormal breast cancer gene. Both of which may be causing more breast cancers to be found earlier. In other words, breast cancer may not be developing earlier in younger generation women, but it's being diagnosed earlier.
Unfavorable lifestyle choices and environmental factors (for example, eating an unhealthy diet or smoking) can increase breast cancer risk and may be causing breast cancer to develop earlier in younger generation women with an abnormal breast cancer gene.
The American Cancer society currently recommends that women with an abnormal breast cancer gene start breast cancer screening at age 25 (compared to age 40 for women with an average risk of breast cancer). Since women with an abnormal BRCA1 or BRCA2 gene are being diagnosed at younger ages, the researchers wonder if screening at an earlier age should be considered in the future.
If you or a close family relative has an abnormal breast cancer gene, it's important that you work closely with your doctor to get the testing and regular screening that's best for your situation and your personal risk. You also should make diet and lifestyle choices to help keep your breast cancer risk as low as possible. Your younger relatives (daughters, granddaughters, nieces) should do the same things.
You can learn more about BRCA1 and BRCA2 gene abnormalities in the Breastcancer.org Breast Cancer Risk Factors: Genetics page.