found that the risk of developing breast cancer increased in women who had mutations of a gene related to BRCA2, the PALB2 gene. The risk varied by age, ranging from 5 times greater among women older than 60, to 9 times greater in women younger than 40.
"On the basis of our estimates of risk, women with loss-of-function mutations in PALB2 should be studied to determine whether enhanced surveillance for breast cancer, in line with that offered to women with mutations in BRCA2, can influence outcomes," said study author Marc Tischkowitz, MD, PhD, of Addenbrooke's Hospital in Cambridge, England, and colleagues. "Risk-reducing surgical options could also be tested."
PALB2 mutations occured in up to 3.9% of families in several countries who had a history of breast cancer. Although data remains limited on the mutation and risk, other studies have also suggested that PALB2 carriers have a greater breast cancer risk than the general population.
"The goal of our study was to estimate the risk of breast cancer associated with inherited loss-of-function mutations in PALB2 on the basis of family data for mutation carriers from many locales, across multiple generations, and with differing family histories of cancer," the authors stated.
For women with PALB2 mutations, the cumulative risk of breast cancer was 14% by age 50, and 35% at age 70. The authors said their findings should push genetic counselors into adding PALB2 to testing panels for BRCA1 and BRCA2.
"On the basis of our estimates, the breast-cancer risk for a PALB2 mutation carrier, even in the absence of a family history of breast cancer, would be classified as high according to various guidelines," the authors concluded.
Researchers obtained data from 362 members of families both with and without a history of breast cancer. Data also showed evidence that PALB2 mutations could more than double the risk of ovarian cancer, though findings weren’t as conclusive.
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Two Genes Add to Breast Cancer Risk [Med Page Today]