Gleason scores in prostate needle biopsy and prostatectomy specimens in prostatic adenocarcinoma: A correlation study

INTRODUCTION: Gleason scoring (GS) categorised prostatic adenocarcinoma into five prognostic grade groups (PGGs); associated with different prognosis and treatment. This study aims to correlate between Gleason scores of needle biopsies with the corresponding total prostatectomy specimens, and to assess the relationship between the percentage of Gleason 4 tumour pattern (GP4) within Gleason score 7 (GS7) needle biopsy groups with the pathological staging.

MATERIALS AND METHODS: Seventy-eight specimens of needle prostate biopsy and its subsequent radical prostatectomy were retrospectively studied. The GSs of the needle biopsy were compared with the corresponding prostatectomy specimens. The percentage of GP4 in GS7 needle biopsy groups was calculated and correlated with the pathological staging.

RESULTS: More than half (60%) of GS 6 needle biopsy cases (PGG 1) were upgraded in the prostatectomy specimen, while the majority (80%) of the GS7 needle biopsy groups (PGG 2 and 3) remain unchanged. Cohen's Kappa shows fair agreement in the Gleason scoring between needle biopsies and prostatectomy specimens, K = 0.324 (95% CI, 6.94 to 7.29), p <0.0005 and in the percentage of GP4 in GS7 needle biopsy groups and their corresponding radical prostatectomy specimens, K = 0.399 (95% CI 34.2 - 49.2), p<0.0005. A significant relationship was seen between the percentage of GP4 in GS7 needle biopsy with the pT and pN stage of its radical prostatectomy (p = 0.008 and p=0.001 respectively).

CONCLUSION: A higher percentage of GP4 in GS7 tumour is associated with worse tumour behaviour, therefore it is crucial for clinicians to realise this in deciding the optimal treatment.