Mammography research reveals cancer dilemma

High-risk women might get cancer from scans used to detect cancer.
CHICAGO TRIBUNE
CHICAGO -- High-risk women who rely on mammograms as a weapon against breast cancer may actually increase their chances of getting the disease, according to preliminary research released Monday.
The study looked at 1,600 European women with genetic mutations that predispose them to get breast cancer. Women who reported having had at least one chest X-ray were 54 percent more likely to develop breast cancer than those who had never had one.
This catch-22, reported in the current issue of the Journal of Clinical Oncology, means women with mutations in BRCA1 or BRCA2 genes might want to consider being screened with magnetic resonance imaging instead of X-rays, doctors said.
It also suggests that women and men with a family history of breast or ovarian cancer might want to consider genetic testing to find out if they carry a mutation before they get any X-rays to the chest area, doctors said.
Exposure to ionizing radiation -- the kind that comes from nuclear fallout as well as from X-rays -- is known to cause breast cancer. But the risk is small enough for the vast majority of women over 40 that experts still recommend annual screening mammograms.
In women under 40, mammograms are less accurate and the radiation is potentially more dangerous. But those are precisely the women most at risk for hereditary breast cancer.
"Maybe after age 30 the risk of cancer is high enough to justify the potential long-term risk of cumulative radiation," said Dr. Olufumilayo Olopade, director of the cancer risk clinic at the University of Chicago Medical Center. "So we traditionally recommend that high-risk women -- especially mutation carriers -- start screening with mammography at 25.
"This [study] calls into question, is it possible by starting so young we might increase their risk?"
Flaws of the alternative
MRI could eventually become the preferred screening tool for high-risk women, said Olopade, who wrote an editorial accompanying the study. But it's not a perfect solution.
MRI alone can be hard to read and can have a high rate of false-positive results, which lead to unnecessary biopsies, said Dr. Virginia Kaklamani, an expert in breast cancer and cancer genetics at Northwestern University.
So, if a radiologist found something suspicious on an MRI, she said, "I'd probably recommend a mammogram" despite the radiation exposure.
"Until we have more research," Kaklamani said, "younger women with a genetic susceptibility to breast cancer are between a rock and a hard place."
David Goldgar, a genetic epidemiologist at the University of Utah and lead author of the study, said it was too soon to draw conclusions about who should or should not have screening mammograms. He said further research was needed to confirm the results.
The study "is not enough to mandate changes in clinical practice," said Dr. Kathy Albain, director of the breast research program at Loyola University Medical Center in Maywood, Ill. "But I think it's enough to modulate our recommendations for certain patients.