Impact of a tertiary Gleason pattern 4 or 5 on clinical failure and mortality after radical prostatectomy for clinically localised prostate cancer

Abstract

Study Type - Prognosis (case series) Level of Evidence 4 What's known on the subject? and What does the study add? It is known that a tertiary Gleason grade pattern 4 or 5 found in RP specimens has a negative impact on recurrence rate regarding biochemical relapse after radical prostatectomy. This is the first publication addressing clinical outcome in patients with a tertiary Gleason grade pattern 4 or 5 showing a negative influence on clinical failure rates.

Objective: To investigate the impact of a tertiary Gleason grade (TGG) pattern 4 or 5 on clinical failure, as the presence of a TGG pattern 4 or 5 in radical prostatectomy (RP) specimens has been associated with biochemical failure.

Patients and methods: In all, 151 consecutive patients undergoing RP between 1985 and 2006 were reviewed, and 148 patients met study inclusion criteria. The RP specimens were pathologically re-examined and the presence of a TGG pattern 4 or 5 was recorded. The endpoint was clinical failure defined as local recurrence and/or development of metastasis at a mean follow-up of 108 months. Univariate analyses were performed using the Kaplan-Meier method. Multivariate analyses were performed using Cox proportional hazards regression.

Results: Clinical failure was more likely among men with presence of a TGG pattern 4 or 5 than in men without a TGG pattern 4 or 5 (P= 0.006). In the subgroup of patients with Gleason score 7 the presence of a TGG 5 was significantly associated with clinical failure rate (P= 0.002). In patients with Gleason score <7 or >7, a TGG pattern 4 or 5 was not associated with increased failure rates. Multivariate Cox regression analyses in patients with Gleason score 7 showed that a TGG pattern 5 was a statistically significant predictor of clinical failure when adjusting for pathological stage, surgical margin status, extraprostatic extension and seminal vesicle invasion (hazard ratio 4.03, 95% confidence interval 1.72-9.46; P= 0.001). Further subgroup analyses showed that a TGG pattern 5 was associated with statistically higher clinical progression rates in patients with Gleason score 3 + 4 (P= 0.03). In patients with Gleason score 4 + 3, a TGG pattern 5 was associated with a trend towards a higher clinical progression rate, although this was not statistically significant (P= 0.189).

Conclusion: A TGG pattern 4 or 5 is associated with decreased clinical recurrence-free survival in Gleason score 7.