Changes in immunohistochemical staining of PSA, PAP, and TURP-27 following irradiation therapy for clinically localized prostate cancer.
OBJECTIVE
To determine if tissue expression of prostate-specific antigen (PSA), prostatic acid phosphatase (PAP), and a prostate-associated monoclonal antibody (TURP-27) is retained after irradiation therapy and to compare these results with serum levels.


METHODS
Immunohistochemical tests were performed on prostatic tissue obtained by needle biopsy or transurethral resection prior to and following definitive irradiation therapy for clinically localized prostatic carcinoma. PSA, PAP, and TURP-27 were studied. Results were compared with serum PSA and PAP values.


RESULTS
All 20 preirradiation specimens stained positively for PSA and PAP; 19 of 20 stained for TURP-27. All 5 of the initial post-treatment biopsy specimens that showed recurrent tumor stained for all 3 markers. In 2 cases, staining for the 3 markers was greatly diminished. Only 8 of 15 post-treatment biopsy-negative specimens stained for all 3 markers. Six of 15 demonstrated loss of tissue expression for all 3 antigens. One specimen stained for PAP and TURP-27 but failed to stain for PSA. Serum PSA levels paralleled tissue expression in recurrent tumor specimens. However, 3 of the post-treatment biopsy-positive cases with PAP expressing tissue had normal serum PAP levels.


CONCLUSIONS
No cases of recurrent tumor with marker-negative tissue were identified. However, benign epithelial prostate cells appear to sustain sufficient damage from irradiation to lose the capacity to produce certain proteins. Diminished contribution of benign glands to circulating PSA, in addition to decreased expression in malignant tissues, may explain the lower than anticipated serum PSA levels in patients who progress after irradiation therapy.
Grob
B M
BM
Department of Microbiology and Immunology, Eastern Virginia Medical School, Norfolk.
Schellhammer
P F
PF
Brassil
D N
DN
Wright
G L
GL
D000135:Acid Phosphatase / Q000378:metabolism* / Q000528:radiation effects; D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm / Q000378:metabolism* / Q000528:radiation effects; D014408:Biomarkers, Tumor / Q000378:metabolism* / Q000528:radiation effects; D001707:Biopsy, Needle; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D011467:Prostate / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects; D017430:Prostate-Specific Antigen / Q000378:metabolism* / Q000528:radiation effects; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy; D013194:Staining and Labeling; D013997:Time Factors
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; C067897:TURP-27 antigen, human; D000135:Acid Phosphatase; D017430:Prostate-Specific Antigen