Phase III trial of cyclophosphamide versus cyclophosphamide, doxorubicin, and methotrexate in hormone-refractory prostatic cancer. A Hoosier Oncology Group study.

BACKGROUND

Between August 1984 and November 1989, the Hoosier Oncology Group conducted a Phase III study comparing cyclophosphamide (CTX) with cyclophosphamide, doxorubicin, and methotrexate (CAM) in patients with hormone-refractory metastatic prostatic cancer to determine whether the addition of doxorubicin and methotrexate to the cyclophosphamide regimen conferred any survival advantage.

METHODS

One hundred three patients were registered and randomized, 99 were evaluable for response, and all were evaluable for survival results. All had histologically confirmed metastatic prostatic cancer and had not responded to hormonal therapy. Fifty-three patients received CTX alone, and 50 received CAM. Seventy-one patients (69%) had evaluable disease, and 32 (31%) had measurable disease.

RESULTS

There were no complete responses and only four (13%) partial responses in the patients with measurable disease. There was no difference in overall survival time between the two treatment arms in either patients with a Karnofsky performance status (KPS) of 80-100 (median survival, 9.0 versus 9.5 months; P = 0.93) or in those with a KPS of 50-70 (median survival, 5.0 versus 6.0 months; P = 0.51). There was no difference in overall time to progression between the two treatment arms (median time to progression; 4.4 versus 6.2 months; P = 0.07). Toxicity was tolerable in both regimens.

CONCLUSIONS

It was concluded that there was no survival advantage to CAM over CTX alone. New chemotherapeutic agents with greater activity against prostatic cancer must be identified.