Studies that shaped Canada’s breast cancer screening guidelines ‘flawed’

(Elizabeth McSheffrey/ Global News) — A group of Canadian and American researchers say they’ve found “significant flaws” in the studies that shaped Canada’s modern breast cancer screening guidelines.

In a new commentary, they suggest lives have been lost because of methodology errors in two Canadian trials, which found mammograms for women in their 40s did not reduce death rates from breast cancer.

Seven other trials conducted around the world, however, found the opposite: mammograms for women did reduce mortality rates in that age group. (…)