Young Women With Mutant Breast Cancer Genes Have High Rates of Relapse After Cancer Treatment
Turner, Haffty, and colleagues studied 104 women treated with lumpectomy and radiation, 52 of whom developed a return of cancer in the treated breast and 52 who did not. Among the 52 patients with return of cancer, 15% had BRCA1 or BRCA2 mutations. When incidence of BRCA1/2 mutations was compared by age, 40% of the women under age 40 had the damaged genes, compared with just 5.2% of women over age 40.
The median time to return of cancer was eight years in women with a BRCA1/2 mutation, compared with five years in women without mutations. The longer time to return of cancer in BRCA1/2 carriers suggests that the new tumors are developed out of tissue left in the breast after the lumpectomy that still harbors the mutated genes rather than a reactivation of the old treated cancer.
Because the amount of tissue left in the breast that contains the mutated genes would be much smaller with a mastectomy than with a lumpectomy, it would be expected that mastectomy should lead to a lower rate of new tumors, the researchers write.
Stephen Edge, MD, director of the breast cancer surgery department at the Roswell Park Cancer Institute in Buffalo, N.Y., analyzed the study for WebMD. He says it makes sense that these women are at risk for second cancers and he believes that most physicians are counseling women about their risk, albeit without hard information to back it up. "At the moment we don't know exactly what that risk is," Edge says. "But if I have someone who has a strong family history -- whether or not they have a defined mutation of BRCA1/2 -- I am discussing with them the risk of potentially developing a second cancer in either breast at some point in the future."
Edge says it is important also to realize that most women under age 40 do not have BRCA1 or BRCA2 mutations, which account for only a small percentage of all breast cancers. Therefore, he says, this study should not be interpreted as saying that women under age 40 should reconsider whether selecting the combination of lumpectomy and radiation is appropriate. "People should not deny women under 40 breast-conserving surgery based on these data," he says. "It would be a gross and egregious error to extrapolate this data to advise women under 40 that they should only undergo a mastectomy."