Low Rate of Gene Mutations Found in Women With Family History of Breast Cancer

Researchers report that a study of women with early-onset breast cancer found that nearly 40 percent had a family history of the disease but fewer than one third of these women carried a BRCA1 or BRCA2 gene mutation.

The researchers at Lund University Hospital in Sweden, studying 262 women who had breast cancer before the age of 41, found that 97 women had at least one first- or second-degree relative with breast or ovarian cancer. But the BRCA1 mutation was found in only 16 of these women and only 5 had the BRCA 2 mutation.

"Considering the high proportion of case subjects with a positive family history of breast cancer in early onset breast cancer cases and the relatively low frequency of BRCA1 and BRCA2 mutations, one would envision that other genetic factors are at play," the researchers reported in the Journal of the National Cancer Institute.

"In our study, the breast cancers in 12 of the 31 index case subjects with a strong family history of breast or ovarian cancer and in 11 of the 28 case subjects with a strong family history of only breast cancer were due to BRCA1 and BRCA2 mutations," said the researchers. "Some remaining families could carry mutations in other susceptibility genes, such as TP53, CHK2, and p16 known to be associated with early-onset breast cancer."

Other Sources: Journal of the National Cancer Institute