Chemotherapy with or without estrogenic recruitment in metastatic breast cancer. A randomized trial of the Gruppo Oncologico Nord Ovest (GONO)

Summary Background: This phase HI study was carried out to verify whether a kinetic recruitment induced with low doses of diethylstilbestrol (DES) could increase the antitumor activity of chemotherapy in patients with advanced breast cancer. Patients and methods: Two hundred fifty-eight women with metastatic breast cancer were randomized to receive chemotherapy consisting of cyclophosphamide 600 mg/sqm i.v., epidoxorubicin 60 mg/sqm i.v. and fluorouracil 600 mg/ sqm i.v. (CEF) on day 1 or DES-CEF (diethylstilbestrol 1 mg orally days 1-3 CEF on day 4) every 21 days. Patients were treated until progression or, if responsive, for a maximum of 10 courses. Results: There were no significant differences between the two treatment arms in response rates (51.3% to CEF and 49.6% for DES-CEF); median progression-free survival (9.4 months for CEF and 11 months for DES-CEF group) or median overall survival (17.3 and 20 months for CEF and DES-CEF arms, respectively). Non-hematological toxicities were superimposable in the two arms, while DES-chemotherapy was more myelotoxic. Conclusions: This trial confirms that chemotherapy preceded by estrogenic recruitment is still in an experimental phase and that, at present, it has no role in clinical practice. Further research is needed to test the possibility of combining different mitogens in the light of new information about breast cancer cell growth.