Here’s the latest in the ongoing debate over mammography. Women who have been urged for years to get mammograms are now getting a new message: weigh the benefits and harms before choosing to be screened.
New Canadian guidelines say that women in their 40s with an average breast cancer risk do not need regular mammograms, while women aged 50 to 74 can wait longer between exams — from every other year, to every two to three years.
The logic behind this is that the benefit for average-risk women is small — and should be weighed against the potential harms of over-diagnosis and unnecessary biopsies.
According to the Canadian Task Force on Preventive Health Care, women are much more likely to have a false positive result than to have their life saved. Screening about 2,100 women aged 40 to 49 once every two to three years for about 11 years would prevent a single death from breast cancer, while about 690 women would have a false positive. In some cases false positives can lead to women having part or all of their breasts removed when, in fact, they do not have cancer.
It is the first time the guidelines have been updated in a decade, and they do NOT apply to women who are considered to be at high risk.
Needless to say there are many dissenting voices and critics accuse the panel of relying on data from older studies that used now obsolete equipment to underestimate the benefits of screening.