[Which factors allow to anticipate the diagnosis of prostate cancer in pin patients? A study on 546 patients].

To analyze which factors allow to assess the risk of finding a prostate cancer (PCa) at repeated biopsies in patients with diagnosis of prostatic intraepithelial neoplasia (PIN).At our institute all patients with a diagnosis of PIN undergo a 6-monthly control biopsy until the achievement of a benign histology or up to a maximum of 4 consecutive biopsies. For this study a retrospective review of clinical and bioptic data of patients with a diagnosis of isolated PIN (i.e. without associated atypical small acinar proliferation or small cancer foci) was carried out. The correlation between these features and the probability to find PCa at the first re-biopsy or at a further re-biopsy was independently analyzed.The data of 546 patients subjected to a median number of 3 biopsies, (mean: 10.8 and 12.9 cores at initial biopsy and at first re-biopsy, respectively), and with a mean “bioptic” follow-up time of 14.8 months, were analyzed. PCa was found in 174 cases (31.8\%): for 116 of them it took place at the first re-biopsy, with a mean latency of 7.8 months from PIN diagnosis, whereas for 58 at a further re-biopsy, with a mean latency of 21.6 months. The risk of diagnosing PCa at the first re-biopsy was statistically correlated with the PSA value--for which a cut-off value of 7 ng/mL was identified--and with an anomalous rectal prostatic examination at the time of the initial biopsy. Differently, the risk of diagnosing PCa after the first re-biopsy correlated with the number of cores positive for PIN at the initial biopsy--for which a cut-off of 4 was identified--and to the ratio between these and the total number of cores, defined as PIN density--for which a cut-off of 50\% was determined. DISCUSSION AND CONCLUSIONS. It is possible to suggest a tailored protocol of controls in patients with a diagnosis of PIN on the basis of the data available at the initial biopsy: a) high PSA value and/or an anomalous prostatic rectal examination: the diagnosis of PCa is probably just unacknowledged by the initial sampling and it is advisable to carry out an early re-biopsy; b) number of cores with PIN equal to or higher than 4 and/or PIN density equal to or higher than 50\%: a true transition from PIN to PCa is likely to happen with time and it is advisable to carry out a delayed re-biopsy; c) no risk factors: just clinical and PSA monitoring to establish the indication to re-biopsy.