Diagnostic utility of a p63/alpha-methyl-CoA-racemase (p504s) cocktail in atypical foci in the prostate.
Prostatic needle biopsy is the preferred method for diagnosing early prostate cancer, providing specific information. In cases of histological cancer mimics, a diagnosis of atypical small acinar proliferation suspected of but not diagnosed as malignancy can be made. In such cases, and in small focus carcinomas, pathologists use 34betaE12, cytokeratin (CK) 5/6 or p63 immunostaining to label basal cells, and alpha-methylacyl-CoA racemase (AMACR/p504s) immunostaining as a positive prostate cancer marker on two distinct slides. However, in cases of small foci, ambiguous lesions might disappear. The purpose of our study was to improve the sensitivity of a cocktail of two antibodies (p63/p504s) with a sample incubation on 260 prostatic specimens, in order to help make a decision in conjunction with standard histology and CK 5/6 immunostaining. We tested 101 small focus prostatic cancers, 104 atypical small acinar proliferation, 19 high-grade prostatic intraepithelial neoplasia, two atypical adenomatous hyperplasia and 34 benign mimics of cancer. After p63/p504s immunostaining, the final diagnoses retained were as follows: 154 prostatic cancers, 14 atypical small acinar proliferation, 30 high-grade prostatic intraepithelial neoplasia, three atypical adenomatous hyperplasia and 62 benign mimics of cancer. To differentiate malignant from benign lesions, we used the criteria of greater sensitivity to p504s/p63 (95%) than to CK 5/6 (57%) or p63 (86%), and higher specificity for p504s/p63 (95%) than for CK 5/6 (88%) or p63 (81%). With the p504s/p63 cocktail, 89% of the ambiguous lesions were classified vs 53% for CK 5/6. Combined use of the two antibodies, one (p504s) as a positive marker and the other (p63) as a negative marker, with a simple immunostaining procedure, may improve diagnostic performance, sensitivity and specificity, leading to a reduction in the risk of false negatives; this technique in cases of atypical small acinar proliferation should reduce the percentage of residual ambiguous lesions and the need for additional biopsies.
Molinié
Vincent
V
Service de Pathologie, Hôpital Foch, Suresnes, France. v.molinie@hopital-foch.org
Fromont
Gaëlle
G
Sibony
Mathilde
M
Vieillefond
Annick
A
Vassiliu
Viorel
V
Cochand-Priollet
Béatrix
B
Hervé
Jean M
JM
Lebret
Thierry
T
Baglin
Anne C
AC
D001707:Biopsy, Needle; D004268:DNA-Binding Proteins; D003937:Diagnosis, Differential; D016147:Genes, Tumor Suppressor; D006801:Humans; D007150:Immunohistochemistry; D053555:Keratin-5; D007633:Keratins / Q000032:analysis; D008297:Male; D010750:Phosphoproteins / Q000032:analysis; D011467:Prostate / Q000737:chemistry / Q000473:pathology; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D019998:Racemases and Epimerases / Q000032:analysis; D012680:Sensitivity and Specificity; D015534:Trans-Activators / Q000032:analysis; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins
D004268:DNA-Binding Proteins; C503940:KRT5 protein, human; D053555:Keratin-5; D010750:Phosphoproteins; C115051:TP63 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D007633:Keratins; D019998:Racemases and Epimerases; C108352:alpha-methylacyl-CoA racemase