BREAST-CANCER DETECTION IN AN INSTITUTION - IS MAMMOGRAPHY DETRIMENTAL

The poor results of the National Breast Screening Study of Canada rega rding the screening of women aged 40-49 have been interpreted to sugge st that mammography might be detrimental. Our comparison of women who had mammography and had their cancers detected by mammography with wom en who did not have mammography and had palpable cancers suggest that this is not the case. There is no detrimental effect; rather, the use of mammography results in an improvement in survival. The poor results of the National Breast Screening Study likely are due to the unbalanc ed allocation of women with advanced cancers to the screened group, th e poor quality of the mammography in the trial, and an insufficient sa mple size.