SEATTLE, April 6 (UPI) -- Breast cancer patients with the breast cancer gene mutations BRCA1 or BRCA2 are more likely to get cancer in the opposite breast, U.S. researchers found.
Breast cancer epidemiologist Kathleen Malone of the Fred Hutchinson Cancer Research Center in Seattle said breast cancer patients who had a BRCA1 mutation had a 4.5-fold increased risk of getting breast cancer in the opposite breast.
Breast cancer patients, who have a BRCA2 mutation had a 3.4-fold increased risk of a subsequent cancer in the opposite breast, the study found.
Carriers of either BRCA1 or BRCA2, who were diagnosed with breast cancer before age 55 had an 18 percent cumulative probability of developing cancer in the opposite breast within 10 years.
About 5 percent of breast cancer patients carry a BRCA mutation, but the younger a woman is at the time of her first breast cancer diagnosis, the more likely she is to have such a mutation, Malone said.
The findings are published in the Journal of Clinical Oncology.
