Prognostic significance of changes in prostate‐specific markers after endocrine treatment of stage D2 prostatic cancer

Background. The prognostic value was determined of prostate‐specific antigen (PSA) and prostatic acid phosphatase (PAP) measured before and after endocrine treatment in 57 patients with newly diagnosed Stage D2 prostatic cancer. Methods. Therapy included orchiectomy or administration of luteinizing hormone releasing hormone analogues or an antiandrogen. Results. The absolute pretreatment PSA (elevated in 100% of patients) but not PAP (abnormal in 93%) predicted disease progression (P < 0.0011), i.e., a poor response to therapy. Fifty‐three patients responded to androgen deprivation with a decrease in PSA level. This declined to normal at 3 and 6 months in 25% of patients. Forty‐nine percent had a greater than 90% decrease in their PSA level. By 1 year, 58% of patients had progressive disease. Both the nadir PSA level and the percent decline from the pretreatment level at 3 and 6 months predicted the progression‐free interval (P < 0.001). Patients with a 90% or greater decline in PSA had a prolonged progression‐free survival. Serial PAP levels were similarly prognostic. Conclusion. It was concluded that PSA was better than PAP in evaluating patients before and after androgen‐deprivation therapy. The nadir level of both markers was an important tool to predict progression‐free survival in patients with metastatic prostatic cancer, Cancer 1992; 70:2302‐2309.