Ovarian function suppression is not indispensable in patients with early breast cancer who are older than age 40.

Abstract

539 Background: Based on SOFT/TEXT studies, ovarian function suppression (OFS) has become the standard treatment for pre-menopausal breast cancer patients. However, a few studies reported more than 80% pre-menopausal breast cancer patients over 40 years old experienced permanent chemotherapy-induced amenorrhea (CIA) after chemotherapy, suggesting that these patients may not benefit from OFS. The purpose of this study was to evaluate the application value of OFS in early pre-menopausal hormonal receptor (HR)-positive breast cancer patients who experienced chemotherapy after 40 years old. Methods: 1386 pre-menopausal patients over 40 years of age with early HR-positive breast cancer underwent chemotherapy from 2010 to 2017 at the Sun Yat-Sen University Cancer Center. Serum hormone levels were used to define pre-menopausal status. OFS only referred to gonadotropin-releasing hormone agonist (GnRHa). Propensity score matching (PSM) was performed to reduce the selection bias between patients administrated with OFS and those without OFS. The prognostic value of OFS was determined using Kaplan-Meier and Cox proportional hazards analysis. Results: A total of 1386 patients (median age, 46 years; rang, 40-55 years) were enrolled in this study, 258 patients were treated with OFS and 1128 patients did not receive OFS treatment. After PSM, there were 258 patients allocated in Non-OFS group and 258 patients in OFS group. There had no statistically significant difference in terms of overall survival (OS) (p=0.5) and disease-free survival (DFS) (p=0.62) between Non-OFS group and OFS group. In Non-OFS group, 100 patients (8.86%) resumed menstruation after chemotherapy, and 1028 patients (91.14%) experienced permanent CIA. There also had no statistically significant difference in either OS (p=0.35) or DFS (p=0.79) between menstrual recovery group and permanent CIA group. In terms of the menstrual recovery duration time of the 100 patients who resumed menstruation, 37 patients (37%) were ≤ 6 months, 18 patients (18%) were 7 ̃ 12 months, and 45 patients (45%) were ＞ 12 months. In terms of the intervals from last time of chemotherapy to the beginning of menstrual recovery, 29 patients (29%) were ≤ 6 months, 16 patients (16%) were 7 ̃ 12 months, and 55 patients (55%) were ＞ 12 months. Finally, we analyzed the survival difference of different menstrual recovery durations and different intervals. We found that there still had no statistically significant difference in different recovery durations (OS, p=0.15; DFS, p=0.19) and different intervals (OS, p=0.11; DFS, p=0.24). Conclusions: In this study, early pre-menopausal HR-positive breast cancer patients who experienced chemotherapy after 40 years old did not benefit from OFS treatment in DFS and OS. These results suggest that OFS is not indispensable in early HR-positive breast cancer patients aged over 40 years.