Abstract
BACKGROUND: Breast cancer (BC) prognosis is influenced by hormones, of which progesterone receptor (PR) status is controversial for BC prognosis, possibly related to clinical characteristics. OBJECTIVE: This study was to determine the impact of PR status on BC prognosis and explore the differences across patient subgroups. METHODS: PubMed, Cochrane Library, Embase, and Web of Science were searched for relevant studies until July 2024. NOS (Newcastle-Ottawa Scale) was leveraged for quality appraisal. Meta-analysis was performed using STATA15.1. RESULTS: Thirty-five studies were included, involving 89,164 patients. PR-negative status was associated with worse overall survival compared to PR-positive status (HR 1.70, 95%CI 1.42 to 2.04; p < 0.001). Similar results were unveiled for disease-free survival (HR 1.62, 95%CI 1.23 to 2.14, p < 0.001), breast-cancer-specific survival (HR 2.45, 95% CI 1.85 to 3.23, p < 0.001), and recurrence-free survival (HR 1.47, 95% CI 1.21 to 1.79, p < 0.001). Subgroup analyses unveiled that conclusions were influenced by region, estrogen receptor (ER) status, human epidermal growth factor receptor 2 (HER2) status, menopausal status, and metastatic status. CONCLUSION: PR loss is associated with worse outcomes in BC, which is influenced by clinical characteristics. Especially in patients with ER + HER2- tumors, PR status may serve as an additional predictive marker.