A worrisome number of prostate cancer (PCa) patients who meet European criteria for active surveillance (AS) might be underdiagnosed, according to a new Austrian study.
Investigators from Medical University of Innsbruck discovered that 41.1% of roughly 200 Caucasian patients at their institution who would have qualified for AS, but opted for radical prostatectomy, had higher-grade disease on final histology from surgical specimens. The patients, aged 40 to 75, were predicted to have Gleason Score (GS) 6 disease at initial transrectal ultrasound-guided biopsy during the period 1995 to 2000 (some had an additional Doppler-enhanced biopsy), but most turned out to have GS 7 disease (typically 3+4); a tiny fraction had GS 8.
Preoperative PSA levels, PSA density, and/or the number of positive cores did not predict worse pathological findings. (Only positive surgical margin was predictable by combining intermediate PSA levels with 2 positive biopsy cores.) Further analyses also showed that the number of biopsy cores (10 vs. 15) and time from biopsy to surgery did not significantly affect results..
“Thus it seems important to inform patients about the risk of under-grading when considering AS in low risk PCa,” suggested lead researcher Jasmin Bektic, MD, and colleagues.
The investigators determined that all 8 patients who experienced biochemical relapse after radical prostatectomy had undergraded PCa at initial biopsy. “This finding indicates that undergrading in patients stratified for AS lead to increased PCa progression,” they stated.
European Association of Urology criteria for active surveillance included PSA less than 10 ng/mL, GS 6 or lower (based on at least 10 cores), clinical stage T2a or lower, and 2 or fewer cancer-positive biopsy cores (with no more than 50% of tumor in any core).
The researchers note that their results contrast with findings from some larger studies, possibly due to factors such as lack of statistical power or sampling bias.