Cell renewal index in the differential diagnosis of atypical small acinar proliferation and adenocarcinoma of the prostate

Abstract

Introduction Singling out such diagnostic category as atypical small acinar proliferation of the prostate (ASAP) determines the necessity of forming additional approaches to differential morphological diagnosis in order to determine adenocarcinoma in time. Cell renewal index (CRI) is actively used to study proliferation and apoptosis in the epithelial cells of hormone-dependent glands, but in prostate pathology this criterion has not been studied.The aim of the study was to characterize the cell renewal index in atypical small acinar proliferation and prostate adenocarcinoma of different degrees of differentiation in order to optimize differential diagnosis.Materials and methods We studied 720 prostate biopsy specimens from 60 patients: Group 1 — 15 patients with ASAP; Group 2 − 15 with adenocarcinoma of high-grade of differentiation; Group 3 − 15 with moderately differentiated adenocarcinoma; Group 4 − 15 with low differentiated adenocarcinoma. We used immunohistochemical method (Ki-67, CPP32) and non-parametric statistical methods of investigation.Results The CRI in ASAP was comparable to that in highly differentiated adenocarcinoma (p=0.5). In moderately differentiated adenocarcinoma the CRI was significantly higher than in ASAP and highly differentiated adenocarcinoma (p=0.004). The greatest increase in CRI was noted in the low-differentiated adenocarcinoma group, which was higher and significantly different from the ASAP (p=0.000), highly differentiated carcinoma (p=0.003) and moderately differentiated prostatic carcinoma (p=0.000) groups.Discussion On the basis of statistical analysis the present study helped to reveal the identity of CRI parameters in ASAP and highly differentiated adenocarcinoma of the prostat, which allows to add a number of morphological criteria for transferring patients from the group of undetermined diagnosis of ASAP to the group of adenocarcinoma. There is a need for further investigation of CRI with multiparametric analysis including investigation of the expression levels of hormones involved in the regulation of cell renewal in the prostate and growth factors associated with them.Conclusion The study allowed to reveal the identity of the CRI in ASAP and highly differentiated adenocarcinoma of the prostate, which can supplement a number of morphological criteria for transferring patients from the group of undeterminate diagnosis of ASAP to the group of adenocarcinoma.