Women with no history of
The U.S. Preventive Services Task Force, an independent advisory panel appointed by the government, sticks by its controversial 2009 decision to recommend mammograms every two years for women ages 50 to 74, though women who wish to start before then can talk to their doctor about it. The panel also advises doctors against teaching patients how to examine their own breasts.
But several other organizations — including the
For women 20 through 39, these groups say, clinical breast exams should be performed every one to three years, and
The National Cancer Institute, part of the
Meanwhile, the National Breast Cancer Coalition, a grass-roots advocacy group, believes there is "insufficient evidence to recommend for or against universal screening mammography in any age group of women," and "the decision to undergo screening for asymptomatic women must be made on an individual level based on a woman's personal preferences, family history and risk factors."
The debate about mammograms revolves around whether screenings do more harm than good among women younger than 50, who are more likely to have false positives and overtreatment of cancers that would never cause symptoms or threaten a woman's life. Mammograms also are more likely to miss cancer in younger women because their breast tissue is more dense, making tumors harder to spot.
In women with the densest breasts, mammography can miss half of cancers later found on ultrasound, according to a 2002 report in the journal Radiology that reviewed screening sessions performed on more than 11,000 women.
The screening guidelines change for women considered at high risk for breast cancer, which means their lifetime risk of getting breast cancer is greater than 20 percent. Among the factors that can contribute to being high risk are having a BRCA1 or BRCA2 genetic mutation or having a first-degree relative with that genetic mutation; having had
Additional assessment tools help determine risk, and all screening decisions should be made in consultation with your doctor.
According to the American Cancer Society's guidelines, women at high risk should get an
1 in 5: Breast cancers may be missed by mammography, according to the National Cancer Institute.