1988 Volume 79 Issue 2 Pages 316-320
Immunohistochemical staining of prostatic acid phosphatase (PAP) was performed in 101 patients with prostatic cancer before and after treatment in order to evaluate histochemical findings in regard to clinical stage, grades and therapeutic effects. The antibodies for prostatic acid phosphatase used in this study consisted of 2 monoclonal types from Hybritech Inc. (MHPAP) and Biogenex Inc. (MBPAP) and a polyclonal type from Milab. Inc. The polyclonal antibody to PAP was stained positively in almost 100% of prostatic tussues taken from the patients before therapy regardless of clinical stages and grades. Utilizing the monoclonal antibodies the rates of positive staining were higher in well differentiated carcinoma (68% in MHPAP and 76% in MBPAP) than in poorly differentiated carcinoma (42% in MHPAP and 33% in MBPAP). Cases which made good response to endocrine therapy showed higher positive rates using monoclonal antibodies (62% in MHPAP and 53% in MBPAP). However, the positive rates were low in cases resistant to the therapy (29% in MHPAP and 19% in MBPAP) and in hormone-refractory cases (38% in MHPAP and 32% in MBPAP). Nine cases which did not respond to multimodal therapy revealed low positive rates in prostatic tissues obtained after the therapy by both polyclonal and monoclonal antibodies. Especially, by the monoclonal antibodies, the rates were extremely decreased (11% in MHPAP and 0% in MBPAP). There was a high correlation of positiveness and negativeness between the two monoclonal antibodies (77% of correlation rate). Histochemical staining technique using monoclonal antibodies for PAP with biopsy specimens of the prostate taken before and during therapy could be a useful marker of prostatic carcinoma to predict the therapeutic effects and prognosis.
