This real-world non-interventional prospective study aims to explore the compliance and reasons for discontinuation of adjuvant OFS endocrine therapy in early HR-positive premenopausal breast cancer patients under different combination regimens of adjuvant endocrine drugs, as well as to observe the impact of the duration of OFS treatment on prognosis. This study adopts a multi-center, prospective, non-interventional design to collect approximately 300 cases of early HR-positive premenopausal breast cancer patients who received OFS treatment. After obtaining informed consent, the demographic data, breast cancer diagnosis information, comorbidities, past medical history, treatment status, clinical outcomes, and adverse events of the patients were collected. The patients were administered medication in accordance with the standard clinical drug protocols and completed follow-up according to the follow-up plan.
