How accurately does prostate biopsy Gleason score predict pathologic findings and disease free survival?

Due to the significant impact on prognosis by subgrouping of prostatectomy Gleason scores < 7, 7, and > 7, we undertook this study to answer whether the biopsy Gleason score was as predictive of disease free survival and assess the correlation with the prostatectomy Gleason score in a modern prostatectomy series.

An analysis of 1,031 patients who underwent radical prostatectomy for clinically localized prostate cancer was performed. All data was prospectively collected. The Gleason score was categorized into 3 different groups (< 7, 7, and > 7) for biopsy and prostatectomy specimens. Disease free survival was then analyzed for each group. Discrepancies between scores and outcomes were evaluated.

Accurate correlation was noted in 54.8, 66.8, and 47.4% of Gleason scores < 7, 7, and > 7, respectively. Overall accuracy was 58.3%. Both, biopsy and prostatectomy Gleason score correlated significantly with disease free survival (P = 0.001), furthermore the classification (Gleason scores < 7, 7 and > 7) was highly significant (P = 0.001). Patients with prostatectomy Gleason < 7 tumors had significant survival advantage over those with biopsy Gleason < 7, (P = 0.001). However, disease free survival was superior for patients with biopsy Gleason > 7 than those with prostatectomy Gleason > 7, (P = 0.02). The overall disease free survival was similar among the patients with Gleason score of 7 (P = 0.12).

It appears that biopsy Gleason score, although oftentimes not correlating strongly with the prostatectomy Gleason score, is an important prognostic factor in prostate cancer. There are significant differences in disease free survival between biopsy and prostatectomy Gleason score categories.