Changes in prostate-specific markers under chronic gonadotrophin-releasing hormone analogue treatment of stage D prostatic cancer

Abstract

Nineteen patients with newly diagnosed advanced prostatic carcinoma were treated with daily inhalations of a gonadotrophin‐releasing hormone (GnRH) analogue (buserelin acetate, Hoechst 766, Frankfurt, FRG), for up to 3 years. Successful long‐term suppression of luteinizing hormone (LH) and testosterone was observed without any escape of testosterone. Ten patients were considered nonresponders, whereas nine were defined as responders (had either stabilized or regressed). Serum prostate‐specific markers, prostatic acid phosphatase (PAP) and prostate‐specific antigen (PSA), were monitored at fixed time intervals throughout treatment in these patients. Simultaneous determinations of both markers was made under treatment in 147 samples. The results suggest a high correlation between the disease state and the level of the markers (P < 0.0001), as well as a very high correlation between serum concentrations of the markers themselves (correlation coefficient = 0.6). Thus, the authors could not point clearly towards a superiority of any marker when monitoring response to GnRH analogue treatment. Contrary to current belief, the pretreatment values of both markers were of no prognostic value with regard to response or survival.