Specific red cell adherence test in benign and malignant lesions of the prostate.

The specific red cell adherence test (SRCA) for blood group antigens has been shown to have some bearing on the invasive potential of bladder tumours. Hitherto there have been few data published from patients with prostatic disease. The results of SRCA testing in 69 such patients are presented. Each of the 30 cases of adenocarcinoma was antigen negative. However, as 18 of 39 patients with only benign hyperplasia were also antigen negative, the test clearly does not reflect extant tumour and is probably not an indicator of subsequent growth of prostatic cancer. Antigen expression was also negative in sections showing prostatitis. As the test was invariably negative in patients with adenocarcinoma, whether or not metastases were present and whatever the degree of differentiation of the primary tumour, it lacks the power to discriminate invasive potential.