OBJECTIVES: To estimate the total number of patients with advanced or metastatic breast cancer hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2-) in Brazil and also the number of patients in each treatment lines (first and second lines).

METHODS: A retrospective analysis was performed based on epidemiological and published data from Instituto Nacional do Câncer (INCA). Were considered the Brazilian female population in 2018 and the prevalence of advanced or metastatic breast cancer to estimate the number of patients with advanced or metastatic breast cancer HR+ / HER2-, followed by the prevalence of postmenopausal patients in each treatment lines. An average rate of 0.7% of female population growth in Brazil was considered based on the last five years data from Instituto Brasileiro de Geografia e Estatística (IBGE) to estimate the population for the next four years (2019 to 2022).

RESULTS: According to available data, it was possible to estimate that there were a total of 7,724 women with advanced or metastatic breast cancer HR+ /HER2- in 2018, of which 2,248 are pre-menopausal and 5,476 are in postmenopausal phase. For those in postmenopausal, considering the profile of Brazilian patients, it is estimated that, 3,177 women will receive the first line of treatment. Furthermore it was estimated a total of 3,192 that will receive second line treatment.

CONCLUSIONS: Breast cancer presents several histological subtypes that can be directly related to prognosis, therefore, it is relevant to estimate these populations in order to customize the treatment for the patients. In this context, it is possible to conclude that this is a significant result considering the studied population, and it is necessary to increase the efficacy and the access to treatment for these patients in Brazil.