Schedule mammograms based on individual risks, study says

Physicians should schedule breast cancer screening based on patients' individual risk factors rather than blanket guidelines based solely on age, according to a July study in Annals of Internal Medicine.

The study authors recommend using patients' breast density, age, family history of breast cancer and past biopsies to determine when and how often to give mammograms.

The study was done on the premise that "maybe a one-size-fits-all mammography schedule is not taking the best advantage of the data we have available to us," said John T. Schousboe, MD, PhD, lead study author and medical director for research at the Park Nicollet Institute, part of Park Nicollet Health Services in St. Louis Park, Minn.

The study's authors used a QALY analysis -- looking at costs per quality-adjusted life year gained by using the risk factors it highlighted. Researchers found that annual mammograms aren't cost-effective when considering the patient's quality and quantity of life.

Instead, their analysis of disease burden indicates the frequency of mammograms should be based on individual risk factors, with all women receiving an initial screening mammogram at age 40.

For example, biennial mammograms were found to be cost-effective for women 40 to 49 who have either high breast density, or both a family history of breast cancer and a previous breast biopsy. The cost-effectiveness of such screening is based on a threshold of $100,000 per quality-adjusted life-year gained.

Personalizing schedules based on risk factors provides the most cost-effective approach to breast cancer screening when considering a patient's quality and quantity of life. "It at least helps move the debate further on how we can make a widespread, large-scale screening test," Dr. Schousboe said.

More study needed

Others say the guidelines are not ready to be applied to patients.

"It really would be great if you could modify screening schedules based on risk, but I don't think we're there yet," said Robert A. Smith, PhD, cancer epidemiologist and director of cancer screening at the American Cancer Society in Atlanta.

One problem is that breast density can't yet be reliably measured, and measurements often vary from one radiologist to another, Smith said. Scheduling screening based on risk is complex and shouldn't be applied until accurate and consistent guidelines are found, he said.

"Public health programs look best when they are simple," said Smith, adjunct professor of epidemiology and hematology/oncology at Emory University School of Medicine in Atlanta.

Conflicting guidelines

Susan Brown, MSN, director of health education for Susan G. Komen for the Cure, said existing conflicting guidelines mean there is already confusion among women and some health care professionals about when and how often to screen for breast cancer. That confusion and other barriers to screening -- such as cost and lack of access -- contribute to the fact that 30% to 50% of women of eligible age aren't being screened routinely.

The American Cancer Society recommends annual screening using mammography and clinical breast examination for all women beginning at age 40.

The American College of Obstetricians and Gynecologists recommends mammograms every one to two years for all women beginning at age 40, and annually after age 50.

Both groups recommend teaching women to do self-breast exams.

Then in November 2009, the U.S. Preventive Services Task issued a report recommending against routine mammograms for women younger than 50 and against teaching self-breast exams.

Instead, the task force said mammograms should be given every two years for women 50 to 74. Whether to start biennial screening before age 50 should be based on individual patients, the report said.

Tailoring mammography schedules based on an individual's risk makes a lot of sense, Brown said. But reliable guidelines have yet to be developed, she said.

"We don't have a good comprehensive risk-prediction model," Brown said. "We all look forward to the day when that's possible."