Friday, May 13, 2011

HGPIN and Prostate Cancer

In a recent Nature Prostate journal article entitled, Predicting prostate cancer at rebiopsies in patients with high-grade prostatic intraepithelial neoplasia: a study on 546 patients, they state:

The aim of this study was to analyse the factors that predict the diagnosis of prostate cancer (PCa) after high-grade prostatic intraepithelial neoplasia (HGPIN). 

Data from 546 patients with HGPIN submitted up to a 6-month series of three rebiopsies, according to an institutional protocol, were reviewed. 

PCa has been found in 174 cases (31.8%), in 116 cases at the first and in 58 cases at a further rebiopsy. 

The risk of finding PCa at the first rebiopsy was:

(i)correlated with the PSA value and 

(ii)with an anomalous digital rectal examination (DRE) at the time of the initial biopsy; 

the risk at a subsequent rebiopsy was correlated to the number of cores with HGPIN, with a cutoff of four, and to the ratio with the total number of cores (‘PIN density’), with a cutoff of 50%, at the time of initial biopsy. 

A tailored protocol of controls can be suggested: (a) higher PSA value and/or anomalous DRE: early extended or saturation rebiopsy; (b) number of cores with HGPIN >4 and/or PIN density >50%: delayed rebiopsy; and (c) no risk factors: PSA and DRE controls.

 Now the counter concern would be equally compelling to consider. Namely of the cases where HGPIN is noted at initial biopsy, and then the second biopsy, especially of a saturation type, indicates total remission, namely all samples being unremarkable, then it begs the question of what happened. We have previously conjectured that perhaps this is a stem cell artifact, namely that the instigating stem cells was opportunistically removed.  There may be an immune system argument and the like. It would however be of much interest to study those cases especially looking for unique CSC surface markers.