Could family members of the opposite sex increase your chances of developing cancer?

Some breakthrough research has just been announced by the American Cancer society – could your family increase your chances of developing cancer?

A new study in the CANCER Journal, has indicated that clinicians should look at family history of all cancers – even those in family members of the opposite sex – to help assess a patient’s risk of developing cancer. This means, that if you have a family history of prostate cancer, you could have an increased risk of developing breast cancer.

We already know that if breast cancer is common in your family, you are at a higher risk, and the same for prostate cancer. But before now, there hasn’t been a cross correlation between the cancers.

Dr Jennifer L. Beebe-Dimmer, PhD, MPH, of the Barbara Ann Karmanos Cancer Institute and Wayne State University School of Medicine in Detroit, studied 78,171 women who enrolled in the Women’s Health Initiative Observational Study between 1993 and 1998 and were free of breast cancer at the start of the study.

In 2009, the participants were followed up and 3506 breast cancer cases were diagnosed. What’s most interesting is that the researchers found that those in the study who had a history of prostate cancer in first-degree relatives (fathers, brothers, sons) were 14 per cent more likely to be diagnosed with breast cancer. In further analyses of the findings, the impact of both cancers were examined and a family history of both breast and prostate cancer was linked to a 78 per cent increase in breast cancer risk.

“The increase in breast cancer risk associated with having a positive family history of prostate cancer is modest; however, women with a family history of both breast and prostate cancer among first-degree relatives have an almost 2-fold increase in risk of breast cancer,” said Dr Beebe-Dimmer.

Dr Beebe-Dimmer also said that patients and even their doctors might not consider family members’ cancer diagnoses however all previous cancer diagnoses should be recorded, no matter what gender in the family.

Have you been diagnosed with a cancer that was already prevalent in your family? What does this new research mean for you?