Effectiveness of adjuvant trastuzumab in women with HER-2+ breast cancer in the SUS.

The aim of this study was to evaluate the effectiveness in a real-world study of adjuvant trastuzumab in women with HER-2+ initial breast cancer in overall survival and recurrence-free survival. A retrospective cohort study was conducted with women who had HER-2+ breast cancer treated with trastuzumab from July 2012 to May 2017 and followed up until July 2021. The death rate was 2.62 per 100 persons/year, and the incidence rate of recurrence was 7.52 per 100 persons/year. The probability of survival at 8.7 years was 85.9%, while the probability of recurrence-free survival in the same period was 62.8%. The use of trastuzumab proved to be effective in the adjuvant treatment of breast cancer in a public health service in southern Brazil. Prognostic factors associated with worse overall survival or relapse did not influence the natural history of the disease, except locally advanced disease at the beginning of treatment. The data presented may prove to be useful in helping to make decisions about whether to use trastuzumab in the treatment of initial or locally advanced breast cancer in the Brazilian SUS.