CONTROLLED CLINICAL-TRIAL OF INTERFERON-GAMMA AS POSTOPERATIVE SURGICAL ADJUVANT THERAPY FOR COLON-CANCER

Purpose: The primary goal of this study was to assess the effectivenes s of interferon gamma (IFN-gamma) to prevent tumor relapse following p otentially curative surgery in patients with high-risk colon cancer, A secondary goal was to determine the effect of IFN-gamma on immune fun ction and to correlate alterations in immune parameters with survival, Patients and Methods: Three to 4 weeks after undergoing resection of all known malignant disease, 99 patients with stage II, ill, or IV col on cancer were randomly assigned to receive IFN-gamma 0.2 mg total dos e by subcutaneous injection daily for 6 months or observation. serial assessment of human leukocyte antigen (HLA)-DR expression and Fc recep tors on peripheral-blood monocytes was conducted in 24 patients who re ceived IFN-gamma and 27 control patients. Results: With a median follo w-up duration of 59 months in patients still alive, there was evidence of a detrimental effect on time to relapse (P = .03) among patients w ho received IFN-gamma. There was no significant difference in patient survival (P = .12). This study has sufficient power to rule out a 25% reduction in death rate for patients who received IFN-gamma (P < .05), Significant enhancement of immune function wets observed in patients treated with IFN-gamma measured by HLA-DR expression (P < .01) and Fc receptors (P < .001) on peripheral-blood monocytes, Conclusion: This s tudy effectively rules out any clinically meaningful benefit for IFN-g amma as surgical adjuvant treatment for patients with high-risk colon cancer. Although significant enhancement of nonspecific immune functio n was seen with this dosage administration schedule of IFN-gamma, this was not associated with any demonstrable antitumor effect. (C) 1995 b y American Society of Clinical Oncology.