The misuse of mammography in the management of breast cancer revisited.

Abstract

A second study of the use of mammography as a diagnostic procedure in women with breast symptoms is reported. In a two-year period during which 468 patients with a new diagnosis of breast cancer were seen, 238 women had undergone mammography before referral to the Department of Radiation Oncology, Westmead Hospital. For 73 (30.7%) patients the mammographic report was falsely negative. Among those 73 patients with a falsely negative mammographic report, 40 women experienced a mean treatment delay of 12.7 months (range, three to 60 months). A negative mammographic result was significantly (P less than 0.001) more likely to be obtained in younger women. When the women with an initially negative mammographic result represented, they did so with disease of a more advanced stage. This, we contend, is related to the delay in their definitive treatment as caused by the first falsely negative mammographic report. Theoretical calculations are presented; under varying conditions of sensitivity and specificity, these show that, even with the addition of specialist opinion, significant proportions of patients with breast cancer will have a mammographic result which is falsely reassuring. The identification of these subsets depends on histological or cytological examination of the tumour. This is a decision that best is made, in our opinion, by a specialist in breast-cancer management.