Bostwick Laboratories® offers the TriVysion® immunohistochemnistry staining to improve the detection sensitivity for prostate cancer on difficult prostate needle biopsies. The TriVysion® immunococktail consists of 3 antibodies: racemase, high molecular weight cytokeratin (34ß-E12) and p63.

Alpha-methylacyl-CoA-racemase (racemase) gene product, also referred to as P504S protein, is an enzyme involved in beta-oxidation of branched chain fatty acids. It has recently been identified as a novel tumor marker for several human cancers and their precursor lesions, including prostate cancer. Moderate to strong staining of this protein is seen in prostate cancer and high-grade PIN, but not in benign prostatic tissue.

High molecular weight cytokeratin antibody (34ß-E12) stains the cytoplasm of basal cells of the prostate, with continuous intact circumferential staining in most benign prostatic tissue. Increasing grades of PIN are associated with progressive disruption of the basal cell layer. Cancer cells consistently fail to react with this antibody.

p63 antibody stains the nucleus of basal cells. Basal cell cocktail (34 ß-E12 and p63) increases the sensitivity of the basal cell detection and reduces staining variability, thus rendering basal cell immunostaining more consistent.

We at Bostwick Laboratories® use the TriVysion® immunohistochemistry staining in routine practice, and find it to be very useful for the diagnosis of small prostate cancers. Negative immunohistochemical stain for basal cells is not diagnostic of carcinoma by itself as occasional benign glands may not show immunoreactivity, so a positive cytoplasmic staining of racemase is of great value in confirming malignancy. A recent study showed that this cocktail staining converted 10% to 50% cases with a suspicious diagnosis to definitive cancer. This test also preserves the valuable prostatic tissue and shortens turn around time, allowing us to get your diagnosis to your physician more quickly. TriVysion® has rapidly become a standard adjunctive test used to reach a definitive diagnosis in prostate biopsies.

Prostate cancer glands: Prostate cancer cells are strongly positive for racemase (red). There are no basal cells in cancer glands. An adjacent benign atrophic gland shows basal cell staining (brown).

References:

1. Shah, R. B., Zhou, M., LeBlanc, M. et al.: Comparison of the basal cell-specific markers, 34betaE12 and p63, in the diagnosis of prostate cancer. Am J Surg Pathol, 26: 1161, 2002.
2. Jiang, Z., Wu, C. L., Woda, B. A. et al.: Alpha-methylacyl-CoA racemase: a multi-institutional study of a new prostate cancer marker. Histopathology, 45: 218, 2004.
3. Zhou, M., Aydin, H., Kanane, H. et al.: How often does alpha-methylacyl-CoA-racemase contribute to resolving an atypical diagnosis on prostate needle biopsy beyond that provided by basal cell markers? Am J Surg Pathol, 28: 239, 2004.