Survival Outcomes and Prognostic Factors of Metastatic Breast Cancer in Elderly Women: A Retrospective Study in Northeastern Morocco.

Introduction Breast cancer (BC) is the most common malignancy among women worldwide and the leading cause of cancer-related mortality in women in Morocco. However, there is limited evidence on survival outcomes and treatment patterns among elderly patients with metastatic breast cancer (MBC) in this setting. Methods We conducted a retrospective cohort study at the Department of Medical Oncology, Hassan II University Hospital in Fez. The study included 101 female patients aged 65 years or older diagnosed with MBC between January 2012 and December 2016. The primary objectives were to estimate overall survival (OS) and progression-free survival (PFS). Secondary objectives included evaluating clinical characteristics, treatment outcomes, and prognostic factors. Results The median age of the cohort was 70.95 years (range: 65-88). De novo stage IV disease accounted for 61.4% (N = 62) of cases, while metastatic recurrence occurred in 38.6%. Among those with recurrence, 32.7% (N =33) had a relapse interval longer than 12 months. The median time to recurrence was 28 months (range: 1-246). The most common molecular subtypes were luminal B (38.6%; N = 38) and luminal A (29.7%; N = 30), followed by triple-negative (16.8%; N = 16) and HER2-positive (14.9%; N = 15). First-line treatments included chemotherapy (81.2%; N = 82), hormone therapy (32.7%; N = 33), anti-HER2 targeted therapy (16.8%; N = 17), and best supportive care (3%; N = 3). Median OS was 56 months (95% CI: 39.21-72.78), and median PFS was 42 months (95% CI: 27.7-56.2). The estimated three- and five-year OS rates were 64.2% and 55%, and the PFS rates were 59.8% and 51.2%, respectively. Univariate and multivariate analyses identified increasing tumour size, liver metastases, de novo metastatic disease, and a relapse interval of less than 12 months as significant poor prognostic factors for both OS and PFS. The presence of visceral metastases or combined visceral and bone metastases was associated with worse OS only. By contrast, hormone therapy was significantly associated with improved survival. Conclusions This study highlights the clinical and therapeutic characteristics of elderly patients with MBC in Morocco. Tumour size, relapse interval, and liver metastases were key prognostic factors for OS and PFS, while hormone therapy was associated with better survival outcomes.