Adjuvant Endocrine Therapy in Premenopausal Women With Hormone Receptor-Positive Early-Stage Breast Cancer: Risk Stratification in a Real-World Setting

Background: Ovarian function suppression (OFS) and hormone therapy (HT) represent an adjuvant option in premenopausal hormone receptor-positive early breast cancer (HR + EBC). The SOFT-TEXT trials showed improved outcomes upon receiving aromatase inhibitors (AIs)/OFS. Methods: In order to estimate the magnitude of absolute improvements, we conducted a retrospective study applying composite risk (CR) to 237 premenopausal HR + EBC patients. Results: Overall, 119 of these received tamoxifen (T)/OFS and 118 received AIs/OFS. The median age was 45 years (ys). After a median follow up of 65 months, recurrence was 6.7% in T patients and 10.2% in AI ones. CR (cutoff: 2.67) and ET duration (five-year cutoff) was found to have a significant impact on DFS. Invasive diseasefree survival (IDFS) at 5 ys amounted to 82.9% for a CR > 2.67 and 95% with CR < / = 2.67 (p 0.0046). Five-year IDFS was 98.3% in patients who had completed 5-year HT compared to 54.6% of those who had stopped before 5 years ( P < .0001). Excluding patients who had discontinued therapy due to disease relapse, IDFS difference at 5 years remained statistically significant (p = 0.03) between the two groups, with an iDFS rate of 86.5% at 5 years in the second group. Adverse events of different grades were reported in 116 and 112 patients in the T/OFS group and the AIs/OFS, respectively. Early discontinuation due to toxicity was 3.8%. Seven patients (19.4%) discontinued therapy due to pregnancy desire (6 in the T group, 1 in the AI one); of these, one patient relapsed. Conclusion: In a real-world setting, treatment options for premenopausal patients who are candidates for HT and OFS should take risk status into account. Therefore, every effort should be made to maintain patient adherence to treatment in order to manage toxicities and improve outcomes.

Automated summary

In premenopausal HR + EBC patients, those who received AI/OFS treatment had lower recurrence rate and higher disease-free survival compared to those who received T/OFS treatment. Patients who completed 5-year hormone therapy had significantly higher disease-free survival than those who stopped before 5 years. However, there were adverse events and early discontinuation issues during treatment.