Abstract:

Background and purpose: Endocrine therapy has been one of the routine means of adjuvant therapy for patients with hormone receptor positive after surgery. This study aimed to analyze the factors influencing short-term effect (estrogen suppression effect) and long-term survival (disease-free survival, DFS) in patients with operable breast cancer after ovarian function suppression (OFS) therapy. Methods: DFS data and clinicopathological parameters for 435 patients with estrogen receptor (ER) positive breast cancer who underwent surgery and completed postoperative standard chemotherapy and endocrine therapy (OFS combined with tamoxifen or aromatase inhibitors) between June 2017 to June 2019 were obtained in Fudan University Shanghai Cancer Center. The authors performed univariate logistic regression and multivariate logistic regression to analyze the influencing factors of estrogen suppression, while log-rank test and COX proportional hazards regression model were used to analyze the influencing factors of disease-free survival. Results: The failure rate of estrogen suppression in patients aged ≤35 years was 8.7%, which was significantly higher than that in patients aged 35-40 years (1%, P<0.05). There was no difference in the level of estrogen decline between goserelin and leuprorelin (P>0.05). Endocrine therapy regimen (HR = 0.49, P<0.05), axillary lymph node status (HR = 4.21, P<0.05), and tumor diameter (HR = 2.00, P<0.05) were all influencing factors of patients' DFS; The prognosis of patients with estrogen suppression failure was poor (P = 0.10), but the efficacy of goserelin and leuprorelin in reducing recurrence and metastasis was consistent. Conclusion: Age is an independent risk factor for the failure of short-term estrogen suppression in breast cancer patients treated with OFS. Endocrine therapy regimen, axillary lymph node status and tumor diameter affect the long-term prognosis of patients with ER-positive operable breast cancer. There was no significant difference in the reduction of estrogen levels and long-term disease-free survival between patients with goserelin and leuprorelin.

Key words: Breast cancer, Ovarian function suppression, Estrogen-receptor positive, Short-term effect, Long-term survival