The scientific community has established that if a woman has a family history of breast cancer, she is at a higher risk of developing the disease herself.
However, a new study has found that a family history of prostate cancer may also increase women’s risk of breast cancer.
Therefore if there is family history of both breast and prostate cancers, the risk for breast cancer is further increased.
Breast cancer affects about 1 in 8 women in the United States at some point during their lifetime.
According to the American Cancer Society, around 231,840 new cases of invasive breast cancer will be diagnosed this year in the United States and more than 40,000 women will succumb to the disease.
Prostate cancer affects about 1 in 7 men in their lifetime.
Researchers analyzed data from 78,171 women who were recruited to the Women’s Health Initiative Observational Study between 1993 and 1998.
At the onset of the study all women were free of breast cancer and were followed for breast cancer development until 2009. During this time period, 3,506 women were diagnosed with breast cancer.
After reviewing self-reported questionnaires that the women completed at a study baseline, the team found that women who had a first-degree relative with prostate cancer were 14% more likely to be diagnosed with breast cancer after the age of 50. A first degree relative is a brother, father, or son.
Women with family history of both breast cancer and prostate cancer were 78% more likely to be diagnosed with breast cancer after the age of 50. This risk is even higher for African-American women.
It is imperative for doctors to check a patient’s full family history of cancer when assessing their risk.
The large population of women included in the study allows for a more accurate estimation of breast cancer risk among those with a family history of breast cancer, prostate cancer or both.
This study is subject to limitations. For example, the findings were based on self-reported family history of cancer which may have been flawed.