Does the tertiary Gleason pattern influence the PSA progression-free interval after retropubic radical prostatectomy for organ-confined prostate cancer?

INTRODUCTION: The Gleason sum is an important prognostic parameter for patients treated with radical prostatectomy for localized prostate cancer. However, frequently more than two predominant Gleason patterns are present in one specimen. In this study we investigated the prognostic significance of tertiary Gleason patterns in radical prostatectomy specimens.

PATIENTS AND METHODS: Between 1994 and 2001, 277 patients underwent radical retropubic prostatectomy (RRP) for clinically localised prostate cancer in our institute. We collected information on Gleason score and cancer volume (CV) for all tumour localizations, clinical and pathological stage, seminal vesicle invasion (SVI) and extra capsular extension (ECE). In case one pattern was seen in more than 95% of the tumour, this pattern was used both for the primary and secondary Gleason pattern, and any other pattern (actually the secondary pattern) was called tertiary. Charts were examined retrospectively for clinical follow up. PSA progression was defined as two subsequent rising PSA measurements above 0.10 ng/ml. Kaplan-Meier time to PSA progression was compared between patients with and without a tertiary pattern.

RESULTS: Overall, of the 223 patients, 106 (48%) were found to have a tertiary pattern, which on average, was 7% of the total tumour volume. Patients with a tertiary pattern had a 5-year risk of PSA progression of 37.3% versus 12.6% in case no tertiary Gleason pattern was present (log rank p=0.0002). There was no prognostic difference between patients with a higher-grade tertiary pattern as compared to those with a lower grade tertiary pattern.

CONCLUSIONS: If present, a tertiary Gleason pattern, whether better or worse than the primary or secondary pattern, is an indication for a worse outcome, as indicated by a shorter time to PSA progression. This suggests that tumour multifocality, rather than the presence of a higher-grade tertiary Gleason pattern has prognostic value.