PHASE-II TRIAL OF 5-FLUOROURACIL AND ALPHA-2B INTERFERON IN PATIENTS WITH HORMONE-REFRACTORY METASTATIC PROSTATE-CANCER

Objectives. Metastatic prostate cancer remains a disease with no effec tive therapy. We treated 13 patients with hormone-refractory metastati c prostate cancer with 5-fluorouracil (5-FU) and alpha-2b interferon. Our objectives were to determine the response rate and toxicity of rec ombinant alpha interferon and 5-FU in patients with hormone-refractory metastatic prostate cancer. Methods. Patients with progressive hormon e-refractory metastatic prostate cancer with adequate hematologic and renal function underwent baseline bone scans, computed tomographic (CT ) scans of abdomen and pelvis, and measurement of prostate-specific an tigen (PSA). Therapy consisted of a 5-day loading course of 5-FU at 50 0 mg/m(2) with alpha-2b interferon 9 million units subcutaneously 3 ti mes weekly followed by weekly 5-FU and alpha interferon 3 times per we ek. Results. When PSA was used as a response parameter with modified N ational Prostatic Cancer Project (NPCP) criteria, no objective respons es were seen. Using NPCP criteria alone, 5 patients had stable disease . Post-therapy PSA values increased from baseline in 8 of 11 patients (2% to 72%) and declined in 3 patients (3% to 16%). Frequent dosage mo difications were required with the dose intensity of 5-FU and alpha in terferon of 57% and 58%, respectively. Toxicity was significant, with 31% of patients having grade 3 to 4 mucositis and 46% grade 3 to 4 fat igue. Conclusions. 5-FU and alpha interferon, when administered at the dosage and schedule utilized in this study, have no clinically signif icant activity and are associated with unacceptable toxicity in patien ts with metastatic prostate cancer. The role of PSA as an indicator of response remains unclear.