Screening Mammograms Every Two Years OK for Older Women

February 5, 2013

Mammograms every two years are just as beneficial to women over 65 as are annual exams - and may reduce false positives.

Mammograms every two years are just as beneficial to women over 65 as are annual exams- and may reduce false positives, according to an article published online in the Journal of National Cancer Institute.

Researchers from University of California San Francisco studied data from 1999 to 2006 of 2,993 women who had breast cancer and 137,949 women who did not have breast cancer. The women were between 66 and 89 years old.

The researchers found no difference in rates of late-stage breast cancer between older women who were screened every year and women who were screened every two years. Current guidelines from the U.S. Preventative Services Task Force, updated in 2009, recommend that women aged 50 to 74 years only be screened every two years.

“Screening every other year, as opposed to every year, does not increase the probability of late-stage breast cancer in older women,” lead author Dejana Braithwaite, PHD, said in a press release. Braithwaite is an assistant professor of epidemiology and biostatistics at UCSF. “Moreover, the presence of other illnesses, such as diabetes or heart disease, made no difference in the ratio of benefit to harm.”

The researchers also found that among women ages 66 to 74, false positives went down in the biennial group. Forty-eight percent of women who were screened annually had false positives while only 29 percent who were screened every other year had false positives.

In light of these findings, senior author Karla Kerlikowske, MD, a professor of medicine at UCSF and a physician at the USCF-affiliated San Francisco VA Medical Center said, “Women aged 66 to 74 years who choose to undergo screening mammogram should be screened every two years.” She added that women in this age group have no added benefit from annual screens and they run a higher risk of having false positive results.