Serum antibody in patients with prostatic cancer

130 serum specimens were evaluated. None of 24 serum specimens from patients with prostatic cancer yielded precipitation of haemagglutination reactions with extracts of normal human prostatic tissue or with preparations of prostatic fluid. In 1 of 5 patients from whom autologous prostatic tissue was available, precipitation was observed. By indirect immunofluroescence 13 (54%) patients with prostatic cancer possessed antibodies reactive with the cytoplasmic membrane (intercellular area?) of primate prostatic secretory epithelium. Membranous autoantibodies were observed in 2 patients from whom autologous tissue was available as substrate. Antibodies to nuclei were observed but these have been considered in view of their ubiquitous nature, as perhaps being representative of non-specific indicators of other immunologic aberrations. In contrast, only 11 (10%) of 106 patients with other than prostatic cancer possessed membranous antibodies; of these, 11 (73%) possessed a genito-urinary disorder (5 benign prostatic hypertrophy, considered by some as predisposing to prostatic cancer and 3 carcinoma of the bladder). While not possessing sufficient specificity for diagnosis, the high incidence of this antibody, 92% positive in patients with advanced disease (Stage III), suggests it may be useful as a prognostic index of patients with metastatic disease.