Introduction Fulvestrant demonstrated benefits in overall survival and progression-free survival in patients with advanced breast cancer, who are hormone receptor-positive and human epidermal growth factor receptor 2 negative. The characteristics, evolution, and survival of patients with hormone receptor-positive, HER2-negative breast cancer treated with fulvestrant were evaluated according to the national treatment coverage protocols of the National Resources Fund, with the aim of understanding the efficacy of fulvestrant in patients treated in usual clinical practice and comparing our results with those from pivotal studies. Methods A database from the National Resources Fund covering the period from 2009 to 2022 was used. Survival curves were assessed using the Kaplan-Meier method, and differences were analyzed using the Log-Rank test. Results A total of 1085 patients with an average age of 63,66 years were included. Following a follow-up of 14 months, the median overall survival was 16 months, and the median progression-free survival was 6 months. The presence of liver and bone metastases was associated with a shorter overall survival. Patients from the public sector and those with a better performance status experienced longer overall survival. Conclusions Our findings provide a valuable perspective for treatment management in a context of limited resources. Overall survival and progression-free survival were somewhat lower than those reported in pivotal clinical trials. The presence of liver and bone metastases was associated with worse prognosis and survival; additionally, patients with worse performance status had shorter overall survival. These findings underscore the need for personalized therapies, opening new lines of future research.
