Metastasis occurs after surgical removal of low-grade prostate cancer in some men, suggesting that close follow-up is warranted even in this group of lower-risk patients.
Although there is an overall 30% recurrence rate a decade after prostatectomy, a man with a Gleason score of 6 or less generally has a more favorable prognosis. It was sought to determine the long-term recurrence risk in these men following definitive treatment.
They assessed 3,235 consecutive patients who had a radical prostatectomy and bilateral lymphadenectomy for prostate cancer between 1972 and 2005 in the University of Southern California/Norris Comprehensive Cancer Center database.
From this group, they identified 1,383 men with a Gleason score of 6, 24% had a score of 5, 4% had a score of 4, and 2% had a score of 3 or 2. Only 2% had node-positive disease. The cancer stages of the group were pT2 (83%), pT3 (16%), and pT4 (1%).
This information is note-worthy because “tumor stage and Gleason score are the most important predictors of recurrence”, as said at the annual meeting of the American Urologic Association.
Biochemical recurrence occurred in 147 patients a mean of 4 years after surgery.
Clinical recurrence (metastasis) occurred in 45 men a mean of 8 years postoperatively.
Metastasis-free survival in the entire cohort of 3,235 men was 96% after 10 years and 94% after 15 years.
Among all patients in the total database with metastasis or recurrence after radical prostatectomy, “26% of PSA recurrences and 20% of clinical recurrences occurred in men with a Gleason score of 6 or less, said the doctor at the University of Southern California, Los Angeles. They called this 20% a “substantial minority.”
Therefore, “tumors with a Gleason score of 6 or lower are low risk. Patients with Gleason score of 6 or below need close follow-up even after definitive treatment.
A meeting attendee noted that the database spans more than 3 decades. He asked one of the doctors if a cancer that was assigned a Gleason score of 6 in the earlier years of the study would be considered a higher-grade tumor today because of more precise detection methods.
In response, the doctor said that they do not know if they would be graded 7 or above that day.