Active surveillance criteria may not accurately identify low-risk prostate cancer
MedWire News: US researchers have raised concerns that active surveillance (AS) criteria for the treatment of low-risk prostate cancer may not accurately identify men with truly low-risk disease.
In their study, between 7% and 17% of newly diagnosed prostate cancer patients who, despite being eligible for AS, chose to undergo radical prostatectomy developed biochemical recurrence after 5 years, the team reports.
This suggests that “a significant subset of men being offered AS have incurable disease at the time of presentation,” say Herbert Lepor and colleagues from New York University School of Medicine.
Furthermore, almost half of eligible AS candidates were upgraded from a Gleason score less than 6 at biopsy, to a Gleason score of 7 or more after surgery, which the researchers note is an exclusion criterion for AS.
The team examined the pathologic findings and biochemical recurrence rates in a cohort of 1565 men treated with radical prostatectomy for prostate cancer.
All men were eligible AS candidates based on meeting one of two sets of criteria. Group 1 (n=205) included men with clinical stage T1c disease, a prostate-specific antigen (PSA) density of 0.5 ng/ml/cm3, and a Gleason score of 6 or less with no more than two positive cores on biopsy. Group 2 (n=771) all had clinical stage T1c or T2a disease, a PSA of 10 ng/ml or less, and a Gleason score of 6 or less with no pattern 4 or 5 disease.
Overall, 45.9% of men in group 1 and 47.2% of men in group 2 were upgraded to a Gleason score of 7 or higher at prostatectomy. Furthermore, 13.1% and 12.3% of men in groups 1 and 2, respectively, had a primary Gleason pattern of 4 or 5.
Stage T3a disease was identified in 7.8% of men in group 1 and 10.9% of men in group 2, while a respective 32.2% and 28.8% cases had an estimated percentage of cancer exceeding 20% in the surgical specimen.
After a mean follow-up of 41.5 months in group 1 and 44.7 months in group 2, the respective 5-year biochemical-free survival (where recurrence was defined as three consecutive PSA rises with a peak of more than 0.15 ng/dl) was 83.2% and 92.9%.
This indicates that “a significant subset of low-risk disease is not actually low risk,” write Lepor et al in the journal Urology.
They conclude: “Our findings question the wisdom of AS in men with low-risk disease who have ‘long’ life expectancies.”
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By Sarah Guy