Cell ploidy: predictive factor of locally advanced prostate cancer

This study was designed to demonstrate that the study of cell ploidy on biopsies of clinically localized prostate cancers can contribute to the diagnosis of a tumour extending beyond the prostatic capsule and can complete imaging for local staging. Analysis of the histological results of 140 patients operated for clinically localized prostate cancer distinguished two groups of patients in whom the initial tumour was Gleason score 6 or 7. The first group was composed of 33 patients whose tumour was classified as pT3 and the second group was composed of 24 patients whose tumour was classified as pT2. The cell ploidy study was performed on biopsies and operative specimens in the two groups. In the pT3N0M0 group, 72% of tumours presented an aneuploid contingent versus 16% of tumours of the pT2N0M0 group. A strong correlation was demonstrated between cell ploidy and tumour stage (p = 0.0002) and a highly significant correlation was observed between tumour stage and the presence of a tumour contingent with ploidy greater than 5C (p = 0.0009). The presence of an aneuploid contingent on biopsies of clinically localized prostate cancer significantly increases the risk of a more advanced tumour. This technique could therefore constitute a simple complementary tool in the staging of prostate cancer in combination with transrectal MRI, but this needs to be confirmed by other studies.