Rebuttal: Should women 40 to 49 years of age be offered mammographic screening?

Dr Deck quotes results from his own study to state that “the reduction in mortality [from screening] is much more substantial among older women.” This argument is always put forth to argue against screening women aged 40 to 49, but is flawed because the improvement in mortality for younger women improves with length of follow-up. 1 Indeed, the numbers quoted from the Agence d’evaluation des technologies et des modes d’intervention en sante study contrast with results published by Tabar’s group 2 : after 20 years’ follow-up of the 40- to 49-year-old group, Tabar and colleagues report a 48% reduction in breast cancer mortality in the screened group compared with 19% in unscreened women. Dr Deck states that the ineffectiveness of mammography in young women is because of a lower risk of breast cancer and denser breast parenchyma. He proposes obtaining a baseline mammogram at age 40 to see if “the image is clear enough.” The premise for this proposition is only partly valid because the detection of 2 of the 3 principal manifestations of cancer on mammography (microcalcifications and architectural distortion) is not hindered by dense breast tissue. The limitations of mammography due to the added anxiety of patients’ receiving false-positive results have been exaggerated—given the choice, women opt for greater sensitivity at the cost of lower specificity. 3 As for the risk of radiation exposure for women in their 40s, I addressed this topic in my initial position paper. It is undeniable that the risk of breast cancer increases with age. Because the cohort of 40- to 49year-old women is so large, however, and will grow to become the largest segment of the population in 2031, 4