Mandatory TNM Staging of Breast Cancer and Harms of mammographic Screening

Abstract

In Australia and many other high and middle-income countries diagnosis of the most curable stages of breast cancer, early breast cancer (EBC), in women by population based mammographic screening began after 1990. In many of these same and other high and middle-income countries administering adjuvant endocrine and chemotherapy after surgical complete resection of EBC (adjuvant therapy) also began in the 1990s. Some populations then underwent declines in breast cancer mortality that were recorded in population-based Cancer Registries that were attributed to either mammographic screening and/or adjuvant therapy. In only a few populations, for example, in the State of Victoria Australia from 1986-2019 long term trends in the incidence of breast cancer stages at diagnosis have been recorded by the population-based Victorian Cancer registry (VCR). These long-term stage trends have shown that advanced stages of breast cancer have increased or remained stable in those populations, so mammographic screening could not have directly caused the recorded declines in breast cancer mortality in their population-based Cancer Registries. In contrast in Victoria Australia adjuvant therapy use can explain all the recorded mortality decline.