Prostate cancer risk appreciable even after two negative biopsies
MedWire News: Approximately a quarter of patients with at least two sets of negative prostate biopsies remain at increased risk for prostate cancer, and the majority of tumors detected are clinically significant, the results of a French study indicate.
The false negative rate among extended sextant biopsies with at least four additional cores from the lateral peripheral regions remains high. However, the recommendations for a third biopsy in patients with increasing prostate-specific antigen (PSA) levels after a negative repeat biopsy are unclear.
Laurent Solomon, Centre Hospitalier Universitaire Henri Mondor in Créteil, and colleagues therefore performed a set of 21-core biopsies under general anesthetic in association with transurethral prostate resection (TURP) in 113 patients with persistently increased or increasing PSA levels after at least two extended negative biopsies.
Prostate cancer was detected in 23.9% of patients, including 63.0% on biopsy alone, 22.2% on TURP chips alone, and 14.8% on biopsy and TURP chips. Extended biopsy had an 18.6% detection rate and detected 77.8% of prostate cancers.
The use of TURP significantly increased the prostate cancer detection rate over biopsy alone by 28.5% for an overall detection rate of 23.9%. The median tumor Gleason score was 6, and 30% had a Gleason score of 7 or above. The average PSA level for Gleason score 6 prostate cancer was 10.8 ng/ml versus 20.4 ng/ml for Gleason score 7 or 8 cancer.
Among 17 patients who underwent radical prostatectomy, the median Gleason score was 7, while 23.5% of tumors were identified as stage pT3–T4 disease, the team reports in the Journal of Urology.
Eighty six patients with no prostate cancer at initial assessment were followed-up for an average 31.8 months. The average PSA level 1 month after TURP was 4.2 ng/ml, at an average decrease in PSA levels of 6.9 ng/ml. In all, 34.9% of patients underwent repeat biopsy, with cancer detected in 16.7%. Patients who had repeat biopsy had an average PSA level of 6.0 ng/ml during 1 year of follow-up versus 3.5 ng/ml among patients who did not have repeat biopsy.
“About a fourth of patients with two extended multisite negative prostate biopsy sets remained at risk for prostate cancer and tumors undetected at initial procedures were not trivial,” the team concludes.
They add: “The diagnostic yield of TURP was moderate but significant and may provide additional data of clinical importance in select patients.”
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a part of Springer Science+Business Media. © Current Medicine Group Ltd; 2009
By Liam Davenport