Periacinar Clefting and p63 Immunostaining in Prostatic Intraepithelial Neoplasia and Prostatic Carcinoma

The aim of the present study was to correlate the presence and extent of retraction clefting and the expression of p63 in neoplastic glands and glands with prostatic intraepithelial neoplasia (PIN) in needle core biopsies. We analyzed needle core biopsies from 28 patients with PIN and 41 patients with adenocarcinoma. Neoplastic glands and those with PIN were analyzed on high power field (400x) and classified in three groups according to the extent of clefting. Immunohistochemical staining was performed following Microwave Streptavidin ImmunoPeroxidase (MSIP) protocol on DAKO TechMate Horizon automated immunostainer. Periacinar retraction clefting was significantly more prominent in prostatic carcinoma compared to PIN (p<0.0001) and nonneoplastic glands (p<0.0001). There was no difference between normal glands and PIN regarding clefting (p=0.8064). p63 was positive around the whole circumference in 12 out of 28 cases with PIN, and discontinuously positive in remaining 16 PIN cases suggesting initial disruption of the basal cell layer. p63 immunostaining was also positive in all nonneoplastic glands, and negative in all carcinomas. We conclude that retraction clefting was associated with cancer and lack of basal cells, but not with PIN. The relationship between clefting and p63 immunostaining in prostatic cancer should be further analyzed.