High Gleason score best predicts disease spread in prostate surgery patients
MedWire News: Patients with a Gleason score of 6 or less after radical prostatectomy have at least an 80% chance of organ-confined prostate cancer and negative surgical margins, translating to a "very high rate of cure," say US researchers.
Conversely, patients with Gleason scores of 8 to 10 have a less than 50% chance that their disease is organ-confined with negative surgical margins, the study results show.
David Schreiber, from SUNY Downstate Medical Center in New York, and colleagues explain that preoperative identification and postoperative management of patients who are more likely to have locally advanced disease is clinically important in order to reduce the risk for prostate-cancer specific mortality in these patients.
The team analyzed data for 35,642 men in the Surveillance, Epidemiology, and End Results (SEER) database to examine the pathologic outcomes of patients with clinically localized disease who underwent radical prostatectomy.
Multivariate analysis, adjusted for patient age, race (Black, White, or other) SEER registry location, prostate-specific antigen (PSA) grouping (≤10.0 ng/ml, 10.1-20.0 ng/ml, and >20 ng/ml), Gleason score (≤6, 3+4, 4+3, and 8-10), and clinical T classification (T1c, T2a-c) was performed to calculate which patient and disease characteristics were most likely to predict extraprostatic extension (EPE) and non-organ confined cancer.
In all, 70.1% of the cohort had organ-confined disease with negative surgical margins, and the remaining 29.9% had either positive surgical margins or EPE.
Among patients with a Gleason score of 6 or less (43.4%), the rate of organ-confined disease with negative surgical margins was between 80.1% and 86.2%, regardless of PSA level or disease classification. However, for Gleason scores higher than 6, the chances of organ-confined disease decreased dramatically.
Specifically, the rate of EPE or positive surgical margins increased from 15.5% for patients with Gleason score 6 tumors, to 33.9% for those with Gleason score 7 (3+4), 47.5% for Gleason score 7 (4+3), and 59.7% for Gleason score 8.
The multivariate analysis revealed a 1.12-fold increased risk for EPE with non-organ-confined disease with every 2-ng/ml increment in PSA level.
Finally, among all patients with EPE and non-organ-confined disease, 11.1% received adjuvant radiotherapy, "indicating that observation or hormonal therapy was the preferred initial therapy for these patients in the community," write Schreiber et al in the journal Cancer.
"This can serve as a baseline for the usage of adjuvant radiation in a large national cohort," concludes the team.
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By Sarah Guy