[Clinical study on poor PSA response to initial endocrine therapy with MAB or estrogenic drugs for treatment of prostate cancer].

Purpose: The prostate specific antigen (PSA) level usually is lowered in response to initial endocrine therapy even in advanced cases of prostate cancer, but in some cases, it is not. We examined the cases in which the PSA level was not sufficiently lowered by initial endocrine therapy with maximal androgen blockade (MAB) or estrogenic drugs.

Materials And Methods: The subjects were 20 patients with prostate cancer diagnosed between January 1992 and December 2005 whose PSA level was not lowered below 10 ng/ml after initial endocrine therapy with MAB or estrogenic drugs. We investigated the frequency of cases, pretreatment PSA levels, PSA nadir levels after initial endocrine therapy and throughout the therapy, PSA response to second line therapy, and the prognosis.

Results: The PSA level was not lowered below 10 ng/ml after initial endocrine therapy with MAB or estrogenic drugs in 4.9% of the cases. Cancer-specific survival rates in all cases were extremely poor, 75.0% at 1 year and 14.7% at 3 years. Prognosis tended to be worse in patients with a higher PSA nadir level throughout the therapy and on whom second therapy was not effective, although the difference was not statistically significant.

Conclusion: The patients whose PSA levels were not lowered sufficiently by MAB or estrogenic drugs had an extremely poor prognosis. These results are useful in planning the therapy, and in explaining the status or future prospective of the disease to patients and their families.