INTRALESIONAL ADMINISTRATION OF BIOLOGICAL RESPONSE MODIFIERS IN THE TREATMENT OF LOCALIZED CANCER OF THE PROSTATE - A FEASIBILITY STUDY

Objectives. The primary aims of this pilot study were to establish the feasibility of intraprostatic administration of biological response m odifiers (BRMs) and to investigate the toxicity and side effects of re combinant interferon (IFN)-alpha-2b injected into prostate glands harb oring cancer. A secondary goal was to perform a preliminary assessment of the antitumor effect of this treatment. Methods. Nine patients wit h histologically documented carcinoma of the prostate participated in the study. IFN was administered weekly for 5 weeks, under transrectal ultrasound visualization, with a modified gun that permitted the contr olled injection of small volumes initially into the area of the tumor and later into the whole gland, Total doses of IFN ranged between 15 a nd 100 MU. Results. The procedure resulted in minor local discomfort, comparable to a prostatic biopsy. Side effects from the drug were thos e anticipated from most BRMs (chills, fever, malaise, headache, fatigu e), and in every case they were minor and self-limiting to several hou rs, Local adverse events were limited to gross hematuria (2 patients [ 22%]) and hematospermia (1 patient [11%]) and resolved spontaneously w ithin 2 weeks. Antitumor activity, a secondary goal of the study, was noted in 3 (33%) patients with limited follow-up (mean 22.5 months). C onclusions, The results of this pilot study indicate that the intrapro static administration of IFN-alpha-2b can be readily accomplished by t he method described here and is associated with minor, self-limited to xicity. With the regimen and doses used, IFN demonstrated modest antin eoplastic activity. Modifications of the schedule, routes, and amounts administered may result in enhanced therapeutic value. (C) 1997, Else vier Science Inc. All rights reserved.