The Significance of Accurate Determination of Gleason Score for Therapeutic Options and Prognosis of Prostate Cancer

Abstract

The Gleason score (GS) to date remains one of the most reliable prognostic predictors in prostate cancer (PCa). However, the majority of studies supporting its prognostic relevance were performed prior to its modification by the International Society of Urological Pathology (ISUP) in 2005. Furthermore, the combination of Gleason grading and nuclear/nucleolar subgrading (Helpap score) has been shown to essentially improve grading concordance between biopsy and radical prostatectomy (RP) specimens. This prompted us to investigate the modified GS and combigrading (Gleason/Helpap score) in association with clinicopathological features, biochemical recurrence (BCR), and survival. Core needle biopsies and corresponding RP specimens from 580 patients diagnosed with PCa between 2005 and 2010 were evaluated. According to the modified GS, the comparison between biopsy and RP samples resulted in an upgrading from GS 6 to GS 7a and GS 7b in 65% and 19%, respectively. Combigrading further resulted in an upgrading from low grade (GS 6/2a) to intermediate grade PCa (GS 6/2b) in 11.1% and from intermediate grade (GS 6/2b) to high grade PCa (GS 7b/2b) in 22.6%. Overall, well-differentiated PCa (GS 6/2a) was detected in 2.8% of RP specimens, while intermediate grade (GS 6/2b and GS 7a/2b) and high grade cancers (≥ GS 7b) accounted for 39.5% and 57.4% of cases, respectively. At a mean follow-up of 3.9 years, BCR was observed in 17.6% of patients with intermediate (9.8%) or high grade PCa (30.2%), while PSA relapse did not occur in GS 6/2a PCa. In conclusion, adding nuclear/nucleolar subgrading to the modified GS allowed for a more accurate distinction between low and intermediate grade PCa, therefore offering a valuable tool for the identification of patients eligible for active surveillance (AS).

Keywords: Carcinoma; Gleason and combigrading; PSA progress; Prognosis; Prostate; Survival.