Abstract: Objective To investigate the symptom clusters, interrelationships among symptoms, and core symptoms in breast cancer patients undergoing ovarian function suppression (OFS) therapy, with the objective of establishing a theoretical foundation for precise symptom management. Methods Convenience sampling was used to select 1,132 breast cancer patients who received OFS therapy at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine from October 2023 to July 2024. General information questionnaire and symptom burden scale were used for the investigation. Exploratory factor analysis was employed to identify symptom clusters, and R language was used to construct the symptom network to analyze indicators of symptom strength (rs), closeness (rc), and betweenness (rb). Results The most common symptoms among breast cancer patients undergoing OFS therapy were hot flashes（98.1%）, anxiety mood （97.9%）, and irritability （97.8%）. Ten distinct symptom clusters were identified: psychological, musculoskeletal, sexual, skin, sleep, nervous, somatic, vasomotor, vaginal, and gastrointestinal. Symptom network analysis showed that the top three symptoms by strength were vaginal dryness (rs=1.265), hot flashes (rs=1.232), and night sweats (rs=1.204); the top three by closeness were night sweats (rc=0.00210), hot flashes (rc=0.00204), and myalgia (rc=0.00195); and the top three by betweenness were night sweats (rb=93.000), hot flashes (rb=77.000), and vaginal dryness (rb=63.000).  Conclusions Vaginal dryness, hot flashes, and night sweats are identified as core symptoms within the symptom network of breast cancer patients undergoing OFS therapy. It is recommended that healthcare professionals closely monitor the changes in these symptoms and implement targeted interventions based on the characteristics of symptom clusters and the network influence of core symptoms, so as to enhance symptom management outcomes.

Key words: Breast cancer, Ovarian function suppression, Symptom clusters, Core symptoms, Symptom network