VANCOUVER—Prostate cancer (PCa) patients who have biopsy Gleason scores of 8, 9, or 10 are lumped together as having “high-risk” disease, but they represent individual subgroups with different long-term oncologic outcomes, according to a study by the European Multicenter Prostate Cancer Clinical and Translational research group. In particular, Gleason 8 tumors are associated with a substantially better prognosis after radical prostatectomy (RP) than Gleason 9 and 10 tumors.
The study, by Steven Joniau, MD, PhD, of the University Hospitals Leuven, Belgium, and colleagues included 344 men who underwent RP with pelvic lymph node dissection for Gleason 8-10 disease. The men had a minimum of 10 years of follow-up.
The researchers found that the 10-year biochemical recurrence-free survival was 42.9%, 25.1%, and 28.6% for patients who had biopsy Gleason 8, 9, and 10 tumors, respectively. The 10-year clinical progression-free survival was 70.7%, 47.2%, and 25%, respectively. The 10-year cancer-specific survival was 84.9%, 66.1%, and 50%. After adjusting for preoperative PSA level, clinical T stage, and age, men with a biopsy Gleason score of 9 and 10 had an approximately 2.5 and 4.0 times higher risk for clinical progression and cancer-related death compared with men who had a biopsy Gleason score of 8.
In a poster presented at the 33rd Congress of the Societé Internationale d’Urologie, the researchers concluded that patients with a biopsy Gleason score of 8 “represent good candidates for RP as primary treatment. Conversely, biopsy Gleason scores 9 and 10 define subgroups with remarkably worse clinical progression-free and cancer-specific survival thus underlining important heterogeneity within the group of high-grade PCa.”
The researchers acknowledged that the small sample size of men with Gleason 10 biopsy scores (seven patients) is a study limitation.
In an interview with Renal & Urology News, Dr. Joniau said he was not surprised by these results. “On further assessment, about 35% of biopsy Gleason score 8 tumors were downgraded to Gleason score 7 or less, while in those with biopsy Gleason 9-10 this percentage was negligible.”
Approximately 10%-15% of patients received neo-adjuvant androgen deprivation therapy (ADT), about 15% received adjuvant radiation therapy, and 20% received adjuvant ADT.