The Median of Progression free survival in Patients with HR+/HER2− Metastatic Breast Cancer Treated with Initial Endocrine Therapy in Eastern Algeria. A prospective study.

Background. Endocrine therapy became the standard in the management of metastatic luminal breast cancer without visceral crisis, and which has proven its effectiveness in terms of PFS (Progression free survival) and OS (overall survival). Although the recommendations are not perfectly applied, and the prescription remains dependent on the preferences of the practitioners. We report the study of 100 patients with de Novo metastatic breast cancer under first-line endocrine therapy; the main objective was the study of the effectiveness of endocrine therapy by measuring the PFS. Methods. We conducted a prospective multicenter study. The recruitment and follow-up of patients was between 2020 and 2023. We have included 100 patients with HR+/HER2− metastatic breast cancer newly diagnosed, and treated in Eastern Algeria. The median of PFS was analyzed in Cox proportional hazards models. We analyzed the median of PFS according to the clinic-histological characteristics and the therapeutic choice of hormone therapy class. Patient anonymity is respected; the study is carried out in accordance with the declaration of Helsinki. Results. The percentage of visceral metastases (47%), the number of metastases greater than one in 79%. the locally advanced forms represents 71%. The SBR grade was mostly 2. The median of PFS was 10.69 months (9.22-12.88), (95% CI).An advanced T, the presence of visceral metastases, the level of Ki67 and the importance of objective response seems to be factors that significantly influence PFS. The type of hormone therapy demonstrated a remarkable difference in PFS, but not statistically significant. Conclusions. this study shows the effectiveness of endocrine therapy in the treatment of metastatic luminal breast cancer. The absence of a codified predictive and prognostic to personalize the therapeutic choice seems to be a challenge for practitioners.