Adjuvant Endocrine Therapy Benefits Younger Women With ER+ Breast Cancer

Premenopausal women younger than 35 years with estrogen receptor-positive (ER+ve) breast cancer have a high risk of cancer recurrence. Adjuvant endocrine therapy mitigates recurrence, but therapy decisions can be difficult to navigate. During the 2017 San Antonio Breast Cancer Symposium (SABCS 2017), Prudence Francis from the Peter MacCallum Cancer Center, in Melbourne Australia, discussed adjuvant endocrine therapy options for premenopausal women with ER+ve breast cancer.

Francis discussed the SOFT trial, where premenopausal women with ER+ve breast cancer received adjuvant therapy with either tamoxifen, tamoxifen plus ovarian suppression, or ovarian suppression plus the aromatase inhibitor exemestane for 5 years. Women who received only tamoxifen had few cancer recurrences. Although tamoxifen with ovarian suppression did not show a significant benefit in the overall premenopausal population, for those women with a high enough risk to receive chemotherapy, ovarian suppression with tamoxifen did reduce the risk of invasive recurrence. The use of exemestane with ovarian suppression further reduced disease recurrence.

Altogether, this suggests that exemestane plus ovarian suppression significantly improves disease-free survival compared with tamoxifen plus ovarian suppression. According to Francis, the benefit of endocrine therapies compared with tamoxifen alone is the most striking for women younger than 35 years.

Reference

Francis PA. Adjuvant endocrine therapy for premenopausal ER+ breast cancer. Oral presentation at: 2017 San Antonio Breast Cancer Symposium; December 6-9, 2017; San Antonio, TX. Abstract CS1-1.