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Chemotherapy Benefits Premenopausal Women but Not Postmenopausal Women in Specific Breast Cancer Cases

A recent prospective trial has shed light on the efficacy of adjuvant chemotherapy in women with hormone-receptor–positive, HER2-negative breast cancer and one to three positive axillary lymph nodes. The study specifically examines the impact of chemotherapy on invasive disease–free survival, revealing a significant difference based on menopausal status.

HCN Medical Memo
This study underscores the importance of considering menopausal status when recommending adjuvant chemotherapy. Premenopausal women with a recurrence score of 25 or lower may benefit from chemoendocrine therapy, while postmenopausal women in similar circumstances are unlikely to see added benefit.

Study Design

• Prospective trial involving 5083 women, 33.2% premenopausal and 66.8% postmenopausal.
• Participants had hormone-receptor–positive, HER2-negative breast cancer with one to three positive axillary lymph nodes and a recurrence score of 25 or lower.
• Randomly assigned to endocrine-only therapy or chemoendocrine therapy.
• Primary objective: Determine the effect of chemotherapy on invasive disease–free survival and its relation to the recurrence score.

Approximately 70% of breast cancers are hormone-receptor positive and HER2-negative.

Key Findings

• No chemotherapy benefit observed in postmenopausal women; 5-year invasive disease–free survival was 91.9% in the endocrine-only group and 91.3% in the chemoendocrine group.
• Significant chemotherapy benefit in premenopausal women; 5-year invasive disease–free survival was 89.0% with endocrine-only therapy and 93.9% with chemoendocrine therapy.
• The relative chemotherapy benefit did not increase as the recurrence score increased.

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