From August 1986 to August 1990, 116 patients with prostatic carcinoma, advanced disease (stage C-D1 only in patients older than 75 years, or D2) were treated with Buserelin (0.5 mg 3 times/day subcutaneously for 7 days, followed by 0.4 mg 3 times/day intranasally) until progression. No concomitant antiandrogens were administered. Of the 108 evaluable patients, 10 had complete remission (CR), 49 partial remission (PR), 46 remained stable while 3 progressed (response rate = 54.6%). Median duration of response was 31 months, median survival was 34 months. The toxicity of treatment was mild and mainly related to the hormonal effect of the drug. Castrate testosterone levels were obtained in all patients except 7. Slight, transient pain increase was noted at day 8 in 12 patients. Absence of symptoms at the start of treatment, well- or moderately differentiated tumor and serum testosterone negativization following Buserelin were associated with a significantly higher response rate as compared to presence of symptoms, poorly differentiated tumor and failure to obtain castrate testosterone levels, respectively. The following prognostic factors were found, at univariate analysis, to be associated with a prolonged survival: stage (C-D1 versus D2), PS (greater than 80 versus equal or less than 80), symptoms (absent versus present) and histological grade (G1 + G2 versus G3). Age and basal T levels did not influence survival. Those patients who obtained a CR or PR survived significantly longer than those with stable disease or progression.(ABSTRACT TRUNCATED AT 250 WORDS)