Endocrine Treatment Toxicity in Breast Cancer: A Good Thing?

Recent studies have shown that in postmenopausal women with hormone-receptor–positive breast cancer, the benefits of adjuvant endocrine therapy seem to be associated with the adverse effects of the treatment (e.g., Lancet Oncol 2008; 9:1143).

To examine this association further, investigators conducted a phase III, multinational, open-label, randomized study of 9766 postmenopausal women with estrogen-receptor–positive or progesterone-receptor–positive breast cancer who were eligible for adjuvant endocrine treatment. Patients received either the aromatase inhibitor (AI) exemestane (25 mg daily for 5 years) or tamoxifen (20 mg daily for 2.5–3 years), followed by exemestane (25 mg daily for 2.5–2 years; sequential regimen).

Patients who reported…