Ovarian function recovery in breast cancer patients receiving adjuvant anastrozole treatment: updated results from the phase 3 DATA trial.

ABSTRACT

PURPOSE: Patients with chemotherapy-induced ovarian function failure (CIOFF) may experience ovarian function recovery (OFR). Earlier, we showed that OFR during treatment with anastrozole impacted the prognosis of hormone receptor-positive (HR+) breast cancer (BC) patients with CIOFF. Here, we present the long-term follow-up results. METHODS: Postmenopausal women with HR+ BC who were 45-57 years of age and received chemotherapy were identified from the phase 3 DATA study (NCT00301457) on the extended use of anastrozole. Eligible patients were categorised into two groups patients with CIOFF and definitely postmenopausal patients. Patients with CIOFF were monitored for OFR. Disease-free survival (DFS), distant recurrence-free survival (DRFS), and overall survival (OS) were compared between patients with OFR and patients without OFR using multivariable Cox regression analyses, including OFR as a time-dependent covariate. BC-specific mortality (BCSM) was compared between groups using the Fine and Gray method. RESULTS: This study included 656 patients 395 patients with CIOFF and 261 definitely postmenopausal patients. OFR occurred in 39 (12%) of 329 patients with CIOFF who were monitored for OFR. The median follow-up time was 13.3 years. Patients with OFR experienced a deterioration in DFS (hazard ratio (HR) = 1.54; 95% confidence interval (CI) 0.85-2.81), DRFS (HR = 1.51; 95% CI 0.73-3.11), OS (HR = 1.64; 95% CI 0.75-3.55), and BCSM (subdistribution HR = 1.98; 95% CI 0.84-4.63) when compared with patients without OFR. CONCLUSION: In patients with CIOFF, OFR during treatment with anastrozole was associated with a deterioration in BC outcomes. These findings underscore the importance of adequate ovarian function suppression in this subgroup of patients.