(RxWiki News) Gene mutations associated with higher rates of breast and ovarian cancer may pose a serious risk to Ashkenazi Jewish (AJ) women, even those without a family history of cancer. This prompted a call for more genetic cancer screening.
As it stands now, genetic screening is usually only recommended to patients with a family history of cancer. In fact, the US Preventive Services Task Force recommended against population screening of the two genes.
"Talk to an oncologist about cancer screening methods."
Efrat Gabai-Kapara, a professor at the Hebrew University Medical School in Jerusalem, led a recent study of 8,195 AJ men.
The authors focused on three mutations of the genes BRCA1 and BRCA2. These two genes produce a protein that helps the body fight cancer. Mutations, or changes, to the gene may increase the risk of breast or ovarian cancer.
Of the patients, 91 had a BRCA1 mutation, 81 had a BRCA2 mutation and three had changes to both genes.
The changes are equally common in men and women. Both mothers and fathers can pass them down.
The authors first tested AJ men for the genetic mutations. From there, they screened female relatives of the men who had the mutated genes.
For AJ women who carried the BRCA1 mutation, the combined risk of either breast or ovarian cancer was 60 percent by age 60 and 83 percent by age 80.
For those with BRCA2 mutations, the risk was 33 percent by age 60 and 76 percent by age 80.
Applied to all AJs in Israel, 11 percent of breast cancer and 40 percent of ovarian cancer cases could be due to the gene mutations, the authors found.
Of the 167 families studied, 51 percent had little or no family history of cancer.
The authors wrote that screening efforts should focus on "clearly damaging mutations" like BRCA1 and BRCA2 — not just family history.
"We suggest that the time has come to apply our knowledge of these genes to consideration of a general screening program, with the aim of reducing the burden of breast and ovarian cancer," the authors wrote.
"It is almost paradoxical that, as there is a major effort underway to reduce access for women to mammography for breast cancer screening, there are calls for more genetic screening," said Daniel B. Kopans, MD, Professor of Radiology at Harvard Medical School and Senior Radiologist of the Breast Imaging Division at Massachusetts General Hospital.
"I certainly support anyone's decision to be tested to see if they have a BRCA1 or 2 gene mutation that carries a very high lifetime risk of developing breast cancer, but we should not lose sight of the fact that genetic mutations only account for approximately 10 percent of breast cancers," he said. "This may increase slightly as we find that there are more women (and men) who develop breast cancer who have unsuspected mutations, but the fact remains that most breast cancer occurs among women who have no known predisposition and none of the known risk factors."
According to Dr. Kopans, "Mammography is not the ultimate answer, but no one has any idea how to safely prevent or cure all breast cancers. Early detection offers a lifesaving benefit for thousands of women."
In an editorial about the study published Sept. 8 in JAMA, Mary-Claire King, PhD, and co-authors echoed that call for widespread screenings of the BRCA1 and BRCA2 genes.
“It is time to offer genetic screening of these genes to every woman, at about age 30, in the course of routine medical care,” they wrote.
Dr. King noted the limitations of using the study group to make general statements about a much larger group.
She wrote that the study “has implications for public health and prevention strategies in the United States,” in part because “large-scale population screening for BRCA1 and BRCA2 mutations was feasible.”
The study was published online Sept. 5 in PNAS.
The Breast Cancer Research Foundation, National Institutes of Health, Israel Cancer Association and Israel National Institute for Health Policy Research funded the study. The authors disclosed no conflicts of interest.