[Value of biopsies in staging of prostatic cancer before radical prostatectomy].

The diagnosis of prostate cancer is confirmed by histological examination of prostate biopsies. In cases of localized prostate cancer, in which radical prostatectomy can be proposed as curative treatment, these biopsies, directly reflecting the cancer, can provide important prognostic elements, by specifying the tumour staging, allowing better patient selection and guiding surgical techniques in order to improve the postoperative histological results either by decreasing the number of pT3 tumours (extraprostatic) or the positive resection margin rate. Only pejorative elements are a good indicator of extraprostatic spread of the tumour: a Gleason score greater than 7, the presence of extracapsular invasion, perineural invasion, seminal vesicle invasion, 66% of positive biopsies are in favour of extraprostatic tumour. In contrast, the presence of apparently favourable prognostic elements, such as a low Gleason score, one out of six positive biopsies, limited invasion of biopsies cannot confirm the presence of a minimally aggressive, intraprostatic tumour (pT2). Other prognostic criteria may be discovered in the future, which will confirm with greater precision the extraprostatic or intraprostatic nature of localized prostatic tumours.