Phase II clinical trial of cis-dichlorodiammine platinum (cis-DDP) for antitumorigenic activity in previously untreated patients with metastatic breast cancer.

A phase II clinical trial was set up in metastatic breast cancer patients who had not received previous cytotoxic drug therapy, involving the administration of cis-dichlorodiammine platinum (cis-DDP). Patients aged up to 75 years and with pathohistologically confirmed disease were entered on the trial. All patients had measurable disease, a performance status (Karnofsky) of greater than 40, and an expected survival of greater than 6 weeks. In all 38 patients entered the trial, and 35 have been evaluated. The predominating metastatic sites included soft tissues (19), visceral organs (12), and bones (7 patients). cis-DDP was administered in a daily dose of 30 mg/m2 IV by a 4-h drip for 4 days, with customary hyperhydration. The results indicate a pronounced antitumorigenic effect of cis-DDP and a response rate of 54% (19/35), with 13 complete remissions (37%) and six partial remissions (17%). In terms of site the best response was obtained in soft-tissue processes (13/19; 68%), followed by visceral organs (4/10; 40%); the response rate was lowest in bones (2/6; 33%). The menopausal status and prior hormone therapy did not essentially influence the results of treatment, unlike previous irradiation. Patients with a lower performance status (40-70) had a significantly lower response rate (36% vs 63%; P less than 0.05). Toxic side-effects were moderate and did not substantially affect the general condition of the patients. A transient increase of serum creatinine was observed in 4 patients, and neurotoxicity in 2 patients. The results of the trial warrant the conclusion that cis-DDP has a pronounced antitumorigenic effect in untreated metastatic breast cancer, particularly in soft-tissue metastases. These results call for additional clinical study of the cytotoxic effect of cis-DDP in untreated metastatic breast cancer.