Objectives: To correlate the primary Gleason pattern among patients with biopsy-derived Gleason 7 tumors with the radical prostatectomy specimen Gleason grading and other clinical and pathologic outcomes.
Methods and materials: Among 474 patients who underwent radical prostatectomy for clinically localized prostate cancer between 1997-2001, 205 (43%) had Gleason 7/10 tumors on pre-operative needle biopsy. Among theses patients, 148 (72.2%) were assigned a primary Gleason 3 pattern (3+4 = 7) and 57 (27.8%) were assigned a primary Gleason 4 pattern (4+3 = 7). The two groups were compared with respect to age, serum PSA levels, Gleason grade in the radical prostatectomy specimen, pathological stage and surgical margin status.
Results: Among patients with 3+4 tumors on needle biopsy, 64% remained primary Gleason grade 3 while 35% were up-graded to a primary pattern 4 following analysis of the radical prostatectomy specimen. Patients with 4+3 tumors on needle biopsy remained primary Gleason grade 4 in 51% of patients, while 49% of patients had their tumors down-graded to a primary 3 pattern (p = 0.09). There were no differences between patients with needle biopsy 3+4 and 4+3 patterns with respect to total Gleason score in the radical prostatectomy specimen (p = 0.42), pTNM stage (p = 0.36), extra-prostatic extension (p = 0.88), surgical margin involvement (p = 0.16), and seminal vesicle invasion (p = 0.19). In contrast, the primary Gleason pattern in the radical prostatectomy specimen correlated significantly with pTNM stage (p = 0.02) and seminal vesicle invasion (p= 0.003), but not with extra-prostatic extension (p = 0.32) and surgical margin involvement (p = 0.17).
Conclusions: Among patients with Gleason 7 adenocarcinoma of the prostate, the biopsy-derived primary Gleason pattern does not appear to correlate with important clinical and pathologic outcomes. The utility of distinguishing a primary Gleason pattern on needle biopsy among patients with Gleason 7 tumors remains unclear given the limited and conflicting literature addressing this issue.