[Value of the antibody cocktail anti p63 + anti p504s for the diagnosis of prostatic cancer].

UNLABELLED

Numerous lesions of the prostate, such as atrophy, adenomatous atypical hyperplasia (adenosis) or PIN can be misdiagnosed with prostatic cancer, and confused with ASAP, leading to perform additional biopsies. In such lesions, the pathologist can perform an immunohistochemical study with the anti-high molecular weight cytokeratin antibody CK903 (34bE12), which confirms the absence of basal cells and supports the diagnosis of prostatic cancer.

AIM OF THE STUDY

To compare markers of basal cells (cytokeratin 5/6, p63) and the marker of prostatic carcinomatous glands (p504s) or alpha methylacyl-CoA racemase (AMACR).

MATERIAL AND METHODS

Retrospective study of 44 cases of paraffin-embedded prostatic specimens (36 biopsies, 4 PER, 1 adenomectomy and 3 radical prostatectomies), consisting in 20 cases of prostatic carcinomas (2 intraductal, 12 Gleason 6 (3+3), 4 Gleason 7 (4+3), 2 Gleason 8 (4+4)), 11 ASAP, 9 PIN (2 low grade, 7 high grade (2 isolated)), and 10 benign lesions (8 atrophy, 1 atypical adenomatous hyperplasia and 1 case of clear cell cribriform hyperplasia). All cases were tested with antibodies to CK 5/6, and with a cocktail to p63 and p504s, after heat antigenic retrieval on NEXES Ventana processor.

RESULTS

Basal cells of normal prostatic glands stained with CK5/6 and p63 in 91,3% and 100% of cases, independently from the fixation procedure (Bouin or Formalin). Carcinomas had a p63-/p504s+ profile, PIN were p63+/p504s+, and benign lesions were p63+/p504s-. We observed an increase in sensitivity: p63/p504s (100%), CK5/6 (80%), p63 (90%), p504s (95%), and specificity: p53/p504s (90%), CK5/6 (87.5%), p63 (90.5%), p504s (90.9%).

CONCLUSION

Our results show that the use of a cocktail to p63/p504s is more specific than the use of CK5/6 alone this technique supports a diagnosis of prostatic cancer in 40% of cases previously considered as ASAP.