Pilot attempt of advanced prostate cancer treatment T3NxMx-1 by intermittent more complete androgen blockade

The aim of the prospective pilot study was evaluating efficacy and tolerance of pharma-cological more complete androgen blockade (mMAB) by using Zoladex LA 10.8 mg, Casodex 50 mg and Proscar 5 mg in patients with advanced prostate cancer (T3,Nx Mx-1).

This five-year study involved 14 patients aged 67-82 years (average 73). Zoladex LA was administered subcutaneously every 3rd month of treatment, and every day 1 tablet Casodex and 1 tablet Proscar. In the time when PSA was <0.1 mg/ml Zoladex and Casodex were withdrawn, and only Proscar was left. The mMAB treatment was resumed when PSA > 0.1 ng/ml. Before and every 3 months the following laboratory tests were made: PSA, sedimentation, bilirubine, transaminase, phosphatase, ultrasonography (USG); and adverse events were registered. The following criteria of assessment were adopted: CR--complete response--examination tests normal, improved condition, reduction of prostate dimension in USG and value of PSA < 0.1 ng/ml; PR partial response i.e. no progression, the PSA level drops down to the reference values and a reduction of prostate dimension in USG occurs, NR--no response i.e. progression, increased prostate dimension in USG and/or metastases in scintygraphy, as well as PSA above normal.

The mean followup time was 60 months. After the initial 6 months two patients were off-therapy mMAB because they were qualified for radiotherapy. A successive patient (no. 5) was off-therapy (after 4 years) because he left Warsaw to go abroad. After 60 months results mMAB were based on 11 patients' records, and a complete response was confirmed in 7 patients, partial response in 3 patients and no response in one patient.

Results of this study show that pharmacological intermittent mMAB is an efficient way of treating advanced prostate cancer. Side effects are low and occur in moderate intensity and do not oblige to treatment withdrawal.