Screening Mammograms Should Not Be Underestimated

I find the article “Likelihood That a Woman With a Screen-Detected Breast Cancer Has Had Her ‘Life Saved’ by that Screening,” by Welch and Frankel,¹ disturbing for several reasons. First, while looking at 20-year survival data has its merits, one should not forget the advances made in annual screening in the last 2 decades and with it the increase in detection of smaller cancers in earlier stages. Surveillance Epidemiology and End Results (SEER) and service data both highlight the downward shift in stage at diagnosis, with 74% of cancers diagnosed at stage 0 or 1.^2- 4 Service data comparing biennial with annual mammograms show the median decrease in size from 15 mm to 11 mm and the decrease in positive axillary lymph nodes from 24% to 14%.⁵ From various clinical trials, the survival curves for the smallest cancers (ie, <1 cm and negative nodes) appear to level off at 95%, suggesting that a cure may have been achieved. At present, consistent discovery of small potentially curable breast cancers is only possible with mammography or other radiologic screens. The push for regular annual screening is driven by the hope of increasing actual cure rates.