PSA density cutoff triggers intervention in prostate surveillance patients
MedWire News: Men with prostate cancer whose prostate-specific antigen density (PSAd) is over 0.15 require definitive therapy rather than active surveillance, suggest study findings showing a high risk for tumor progression in this population.
Active surveillance is an established treatment option for the management of selected patients with localized prostate cancer, with PSAd values below 0.15 indicative of a potentially low risk for progression among these patients.
However, the prognosis of prostate cancer in men with PSAd values above 0.15 is not well-established.
Armen Aprikian (Montreal General Hospital, Quebec, Canada) and colleagues therefore examined the correlation between diagnostic PSAd and subsequent PSA kinetics (including PSA velocity [PSAV] and doubling time), serum testosterone levels, and tumor upgrading in 102 prostate cancer patients undergoing active surveillance between 1992 and 2007.
The men were aged an average of 66 years and were followed-up for an average of 61 months.
The researchers found a significant difference between men with PSAd values below and above 0.15 on measures of PSAV (0.64 vs 1.31 ng/ml per year, respectively), serum free testosterone (34.2 vs 19.5 pg/ml, respectively), and the incidence of high Gleason score (≥7; 6% vs 23%, respectively).
Of the 101 patients who underwent at least a second biopsy, the rate of upgrading was significantly higher among patients with PSAd values above 0.15 compared with those with values below 0.15, at 31% versus 10%, respectively.
Multivariate analysis revealed PSAd to be an independent significant factor predicting tumor progression on repeat biopsy when using a cutoff value of 0.15. Indeed, none of the five (out of 25) patients with upgrading on repeat biopsy had PSAd values below 0.15.
No correlation between initial serum PSA and PSAV on follow-up was observed.
"Although low PSAd is an accepted measure for suggesting insignificant prostate cancer, our study expands its role to indicate that PSAd less than 0.15 may be an additional clinical parameter that may suggest indolent disease, as measured by future PSAV and repeat biopsy over time," conclude Aprikian and team in the journal Prostate Cancer and Prostatic Diseases.
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By Ingrid Grasmo