Adjuvant aminoglutethimide for postmenopausal patients with primary breast cancer: analysis at 8 years

The study purpose was to evaluate aminoglutethimide (AG) as adjuvant therapy in patients with primary node-positive breast cancer in a randomized double-blind placebo-controlled trial.

In a multicenter trial, 354 postmenopausal women with early breast cancer and histologically confirmed positive axillary lymph nodes were randomized after surgery to received aminoplac. Patients were prescribed either AG 250 mg four times per day and hydrocortisone 20 mg twice per day or placebos of identical appearance for 2 years.

After a median follow-up of 8.1 years, there has been no overall benefit for AG in terms of either event-free survival or overall survival (OS). However, the results are consistent with interim analyses with a significantly improved event-free survival for patients who received AG for up to 4 years, although this benefit subsequently disappears. Similarly, there is an improved OS for patients who received AG for up to 4 years, but this also subsequently disappears. There was a marginal advantage for estrogen receptor (ER)-positive patients who received AG (n = 74; P = .054). There was no difference in the sites of relapse. There was a significant increase in toxicity for patients who received AG.

The lack of survival benefit with long-term follow-up for AG may indicate that aromatase inhibitors have less of an impact on early breast cancer than tamoxifen and may imply different biologic mechanisms of action.