[834] The Impact of the 2005 Modified Gleason Grading System on the Clinical Outcome of Prostate Cancer

Fei Dong, Chaofu Wang, A Brad Farris, Shulin Wu, Hang Lee, Aria F Olumi, W Scott McDougal, Robert H Young, Chin-Lee Wu. Massachusetts General Hospital, Boston, MA

Background: The 2005 International Society of Urological Pathology (ISUP) Consensus Conference modified the Gleason grading system for prostate cancer. In the modified criteria, certain architectural features of classical Gleason pattern 3 adenocarcinoma were reclassified as Gleason pattern 4. In this study, we evaluated the clinical outcomes of patients with prostate cancer upgraded by ISUP criteria.
Design: The histology of 1240 consecutive radical prostatectomy specimens at a single institution between 1993 and 1999 were reviewed, and each case of adenocarcinoma was graded based on the original and modified Gleason grading systems. The outcomes of 806 patients with classical Gleason score 3+3=6 or 3+4=7 and modified Gleason score 6 to 8 prostate cancer were analyzed, with a median clinical follow up of 11.9 years.
Results: Of 622 patients with classical Gleason score 3+3=6 prostate cancer, 210 (34%) had modified Gleason score 7 or 8 by the ISUP criteria. Compared with patients with modified Gleason score 3+3=6 and classical Gleason score 3+4=7 cancer, patients with classical Gleason score 3+3=6 and upgraded by ISUP criteria were at intermediate risk for biochemical progression, the development of metastatic disease, and overall mortality following radical prostatectomy (log-rank p < 0.0001). The hazard ratio for upgrading was 1.60 (95% confidence interval 1.09 to 2.35, p = 0.02) for PSA failure and 5.02 (95% confidence interval 1.77 to 14.2, p = 0.003) for the development of metastasis.


Conclusions: Patients with classical Gleason score 3+3=6 prostate cancer and upgraded by the ISUP modified Gleason grading system are at intermediate risk for biochemical failure following radical prostatectomy compared to patients with modified Gleason score 3+3=6 cancer and patients with classical Gleason score 3+4=7 cancer. The recognition of this intermediate-risk histological pattern may be useful in guiding the prognosis and clinical management of patients with prostate cancer.
Category: Genitourinary (including renal tumors)

Wednesday, March 21, 2012 9:30 AM

Poster Session V # 118, Wednesday Morning

 

Close Window