Five cancer myths exposed

Heredity

The myth: Women with a family history of breast cancer can stop worrying if they test negative for the BRCA1 and BRCA2 genes

 

If you have a family history of breast cancer and test negative for the BRCA1 and BRCA2 genetic mutations, you still (unfortunately) have a high risk of developing breast cancer, according to a new study by Steven A Narod, MD, director of the Familial Breast Cancer Research Unit at the Women's College Research Institute in Canada. Narod's research found that family history is a much better indicator of breast cancer risk than genetic testing, which identifies only about four per cent of all breast cancer cases in women with a family history of the disease.

 

"For every woman found to have a mutation," says Narod, "another four who tested normal are also in the line of fire due to family history." Women in the latter group face about a 40 per cent chance of developing cancer (compared with an 80 per cent risk among women with the mutation). The risk varies by family, however, says Narod. That 40 per cent chance applies only if three or more of your relatives - including a sister or your mother - have had breast cancer. Assuming you don't have the mutation and have only one family member who's had breast cancer, you have about a 12 or 13 per cent risk of developing the disease. Narod estimates that if no one in your family has had it, your risk drops to 10 per cent until the age of 75. If you do have a family history of breast cancer and test negative for the BRCA1 and BRCA2 mutations, stay vigilant.

 

Watch for changes in your breasts, check yourself weekly and have regular mammograms. And speak with your GP about preventative options. And though you're not in the clear when it comes to breast cancer, you can at least cross ovarian cancer off your list of worries. Women who tested negative in Narod's study didn't develop the disease, which is common among women with the BRCA1 and BRCA2 mutations.

 

See our Breast Cancer Awareness Month 2009 special