Active surveillance is only moderately able to reduce the harmful effects of prostate cancer overdiagnosis from PSA testing, according to an analysis of the long-term outcomes of men enrolled in the Prostate Cancer Research International Active Surveillance program.
San Francisco-Active surveillance is only moderately able to reduce the harmful effects of prostate cancer overdiagnosis from PSA testing, according to an analysis of the long-term outcomes of men enrolled in the Prostate Cancer Research International Active Surveillance (PRIAS) program, a prospective observational study assessing active surveillance in real-world practice.
The results, which were published in Translational Andrology and Urology (2018; 7:98-105) and presented at the 2018 AUA annual meeting in San Francisco, considered the first 500 men entered into PRIAS. At enrollment, all of the men had very low-risk or low-risk disease with a Gleason score (GS) 3+3.
During a median follow-up of 6.5 years, the 500 men underwent a total of 838 biopsies, and the vast majority of those (79% or 90%) did not lead to risk reclassification. Nevertheless, 249 men (50%) switched from active surveillance to invasive treatment within 10 years of follow-up, and 18% of the switches were for reasons other than reclassification per PRIAS protocol criteria.
Furthermore, a review of pathology findings available from 99 men who underwent radical prostatectomy showed that 34% had low-risk disease (GS 3+3 and ≤cT2), 33% had “low” intermediate-risk disease (GS 3+4 and ≤cT2), 7% had intermediate-risk prostate cancer (GS 4+3 and ≤cT2), and 25% had high-risk or locally advanced prostate cancer (GS ≥4+4 or ≥T3), reported first author Frank-Jan H. Drost, MD.
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“The current U.S. Preventive Services Task Force recommendation to counsel men on PSA screening for prostate cancer is based in part on the idea that active surveillance for men with low-risk prostate cancer can prevent direct overtreatment and reduce the harms associated with overdiagnosis. But our study showed that active surveillance can still lead to many unnecessary, potentially harmful biopsies. In addition, it does not solve the problem of overtreatment, which occurred in at least one-third of men.
“Furthermore, it should be stressed that half of patients eventually do switch to active treatment, of which 18% does so without an indication of risk reclassification (eg, for anxiety),” said Dr. Drost, PhD candidate, departments of urology and radiology and nuclear medicine, Erasmus University Medical Center, Rotterdam, the Netherlands.
“Therefore, we believe that the ability of active surveillance to reduce the risk of harms from PSA testing might be overstated. Although it can prevent overtreatment in the beginning, it does not give carte blanche to perform PSA screening in all men. Rather, clinicians should be selective when counseling patients about PSA screening and aim to avoid overdiagnosis of prostate cancer in the first place.”
The analysis of outcomes from PRIAS included men enrolled at 30 centers across eight countries from the time of the study launch in December 2006 through July 2008. During that period, the PRIAS protocol recommended PSA testing every 6 months, annual digital rectal examination, and biopsy at planned timepoints of 1, 4, 7, and 10 years and every 5 years thereafter or yearly if PSA doubling time was 0 to 10 years. The protocol also recommended a switch to active treatment for grade reclassification, two or more positive cores, and stage >cT2.
At enrollment, the 500 men included in the outcomes study had a median age of 65.9 years and median PSA of 5.3 ng/mL; 80% had cT1c disease and 69% had one positive biopsy core.
Biopsy reclassification was identified using two sets of criteria. Based on upgrading alone to GS ≥3+4, only 10% of the 838 biopsies led to reclassification. When the definition considered criteria of GS ≥3+4 or two or more cores positive, 21% of biopsies led to reclassification.