A study found breast tumors in younger women can grow rapidly - from too-small-to-be-detected to large - in less than two years, suggesting that those worried about cancer should get mammograms every year.
Doctors have known that mammograms are less effective in finding cancer in young women. Previously, they assumed the reason was that younger women have denser breast tissue and less fat in their breasts than older women, making malignancies more difficult to see on mammograms, or X-ray images of the breast.
But in a study of 28,271 women age 30 and older who underwent mammograms between 1985 and 1992, researchers found that breast density did not affect the accuracy of mammograms in women under 50.
“For women under 50, we’re not sure technology is the issue. The problem is you have a disease that is not very amenable to screening. It’s not a slow-growing disease,” said the study’s lead author, Dr. Karla Kerlikowske.
The study is in today’s issue of The Journal of the American Medical Association.
Why tumors grow more rapidly in younger women is unclear, Kerlikowske said, but it is probably linked to premenopausal hormones.
Based on their findings, the researchers recommended a mammogram every one or two years for women over 50.
And if women younger than that want screenings, they should be done at least every year because of the cancer’s high growth rate, said Kerlikowske, who stressed that she wasn’t necessarily recommending annual screenings for younger women.
The American Cancer Society and the American College of Radiology recommend that women get mammograms every one to two years after age 40.
The National Cancer Institute currently says there is not enough scientific evidence to justify mammograms every one to two years until age 50. But the institute plans to review that decision this fall. Although the research didn’t address the issue of whether more frequent screenings for young women would save lives, Dr. Peter Jokich, director of breast imaging for RushPresbyterian-St. Luke’s Medical Center in Chicago, said the study is another reason to recommend annual mammograms for patients.
“And that’s also what I tell my wife and family members,” he said.