ORIGINAL ARTICLE

Comparison of annexin II, p63 and -methylacyl-CoA racemase immunoreactivity in prostatic tissue: a tissue microarray study

Jocelyn Stewart¹, Neil Fleshner², Heather Cole¹ and Joan Sweet¹

¹ Department of Pathology, University Health Network, Toronto General Hospital, Toronto, Ontario, Canada
² Department of Surgery, Division of Urology, Princess Margaret Hospital and University of Toronto, Toronto, Ontario, Canada

Correspondence to:
Correspondence to:
Dr Joan Sweet
E11-037 200 Elizabeth Street, Toronto, Ontario, Canada, M5G 2C4; joan.sweet{at}uhn.on.ca

Background: Current ancillary markers for diagnosis in prostate biopsies include p63 and -methylacyl-CoA racemase (AMACR). Annexin II (ANXII), a calcium and phospholipid binding protein, is lost in prostate cancer.

Aims: To investigate ANXII expression in order to assess its utility as a novel diagnostic marker in comparison to p63 and AMACR.

Methods: Using immunohistochemistry on six tissue microarrays, ANXII, p63, and AMACR expression was analysed from 210 radical prostatectomy cases. Staining was evaluated in benign and atrophic glands, high-grade prostatic intraepithelial neoplasia (HGPIN), and prostatic adenocarcinoma. Separate scores were given for ANXII, AMACR and p63 expression.

Results: Diffuse cytoplasmic expression of ANXII correlated with p63 reactivity in basal cells. Benign glands were positive for ANXII in 286/292 cores (98%) and negative for AMACR in all 292 cores. HGPIN showed heterogeneous expression of AMACR and ANXII. A significantly larger proportion of HGPIN glands were correctly identified as ANXII negative than as positive for AMACR. ANXII loss in prostate cancer was found in 282/320 cores (88%) and correlated with positive AMACR expression (272/320 cores, 85%), which was not statistically significant. There was no statistically significant correlation between ANXII scores and the clinical parameters examined.

Conclusions: Immunohistochemical staining for ANXII is a consistent and reliable marker of prostatic neoplasia. The findings of this study suggest the potential utility of ANXII as a diagnostic aid in prostate cancer histopathology.

Abbreviations: AMACR, -methylacyl-CoA racemase; ANXII, annexin II; HGPIN, high-grade prostatic intraepithelial neoplasia

Keywords: annexin A2; -methylacyl-CoA racemase; diagnostic markers; prostatic intraepithelial neoplasia; prostatic neoplasms

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