Diagnostic utility of triple antibody (AMACR, HMWCK and P63) stain in prostate neoplasm

In recent period, basal cell markers high molecular weight cytokeratin (HMWCK), P63 and prostate biomarker AMACR have been used as adjuvant to morphology in diagnostically challenging cases with a very high sensitivity and specificity.

In this prospective study, total of 80 cases including 40 cases of malignant lesions and 40 cases of benign lesions of the prostate were taken. Tumor grade was determined according to Gleason's grading system. AMACR, HMWCK, P63 expressions were determined by immunohistochemical staining.

This study showed AMACR had a sensitivity of 90%, specificity of 100%. AMACR was not expressed in any of the 40 cases of benign lesions of the prostate while in malignant lesions of prostate it was expressed in 36 of 40 (90%) cases; 15 of 16 (93%) of well-differentiated carcinoma were positive for AMACR expression; 17 of 19 (89.47%) moderately differentiated and 4 of 5 (80%) cases of poorly differentiated tumors were positive for AMACR. There was statistically significant difference in expression of AMACR between benign and malignant lesions of the prostate (P = 0.001). In benign lesions, HMWCK and P63 were expressed in all the 40 (100%) cases, while in malignant lesions of prostate it was not expressed in any of the (0%) case. AMACR expression was not seen in any of the benign lesion. Out of 40 malignant cases, 4 cases were negative for AMACR, HMWCK and P63, 36 cases were positive only for AMACR, but no case was positive for HMWCK and P63.

As an adjunct to biopsy, AMACR, HMWCK and P63 have potential for combating diagnostically challenging cases.