Biennial mammograms best after age 50

Screening for breast cancer every two years appears just as beneficial as yearly mammograms for women ages 50 to 74, with significantly fewer false positives, according to new research.

The study, conducted by the University of California - San Francisco (UCSF), US, found that this was true even for women whose breasts are dense or who use hormone therapy for menopause. The same team of researchers from the university and Seattle-based Group Health Research Institute recently reported similar results for older women ages 66 to 89 years old.

In contrast, women in their 40s with extremely dense breasts who undergo biennial mammography are more likely to have advanced-stage and large tumours than women who undergo annual mammography - but annual mammograms also resulted in more false positives, according to the new study from the Breast Cancer Surveillance Consortium (BCSC).

Having dense breasts means it is difficult for X-rays to pass through the breast tissue.

Study senior author Dr Karla Kerlikowske, professor of medicine at UCSF and physician at the San Francisco VA Medical Center, said: “Increasing age and high breast density are among the strongest risk factors for the disease.”

The researchers reported in 2012 that certain risk factors may contribute towards individual decisions that women make with their doctors about when to start breast cancer screening and how often to go about the process.

For example, a family history of breast cancer raises the chance of developing the disease but it does not increase the likelihood of developing advanced-stage tumours or large tumours, which could affect how often a woman should be screened.

Dr Kerlikowske explained: “These individual decisions involve evaluating the balance between the benefits of screening - detecting cancer early - and the potential harms, such as false positives among healthy women.

“Some people who are at higher risk of disease may be more willing than those at lower risk to accept such potential harms of screening."ADNFCR-2094-ID-801832807-ADNFCR