Letter to the Editor.

We read the article by Turk et al. [1] with interest. The authors demonstrated that prostate specific antigen (PSA), Gleason Score (GS) and extra-capsular tumour spread (ECS) can all be used for guidance in choosing a treatment modality for post-RP biochemical recurrence (BCR) and as predictive factors in metastatic disease.

We believe that despite the large number of patients studied, GS is a predictive factor for BCR and metastasis; and it should be noted that GS 7 has two different components (GS 3+4 and GS 4+3). Many of these studies demonstrate worse BCR rates and pathologic stages for patients with GS 4+3 compared with GS 3+4 [2, 3]. Additionally, the authors stated that GS 4+3 carcinomas behaved more similarly to tumours with GS 8 than GS 3+4. The authors offer us, “based on these clinical outcomes and the excellent prognosis for patients with low Gleason scores, we recommend Gleason grades incorporate a prognostic grade grouping which accurately reflects the prognosis” [2]. This study gave GS 7 a sum of 3+4 and 4+3. However, we know GS 3+4 is Prognostic Grade Group II and that GS 4+3 is Prognostic Grade Group III.

In Turk et al.'s article, GS 9 (70%) tumours have lower BCR rates compared with GS 8 (92.3%) [1]. However, recent studies clearly show that GS 9–10 tumours have almost twice the risk of progression compared with GS 8 [4]. Due to the low number of patients (352 patients), statistical analysis shows different results compared to studies with a larger number of patients. The authors should increase the number of patients in their study.