To investigate the potential utility of a new combined immunostaining technique for diagnosing prostate cancer from histological analysis of needle biopsy specimens.
Tissue was immunostained with a combination of antibodies against a basal cell marker (p63), and an enzyme commonly overexpressed in prostate cancer (p504s), on 63 small prostate cancer foci (<1 mm) and 109 cases of ambiguous lesions observed in needle biopsies.
After p63/p504s immunostaining, 93% of the ambiguous lesions (102/109) were classified. The final diagnoses retained were: 92 prostate cancers, seven atypical small acinar proliferations suspected of being malignant but undiagnosed, 21 prostatic intraepithelial neoplasia, five atypical adenomatous hyperplasia, and 36 atrophic benign mimickers of cancer.
Combining p504s as a positive marker for prostate cancer and p63 as a negative marker might improve diagnostic performance, sensitivity and specificity, and lead to fewer false-negative results. This simple immunostaining procedure should reduce the percentage of residual ambiguous lesions and the need for additional biopsies.