Which factors predict biopsy reclassification in men on surveillance for prostate cancer?
High genomic score, prostate-specific antigen (PSA) kinetics, and PSA density ≥0.15 are predictive of biopsy reclassification within 3 years of commencing active surveillance, according to a study. Moreover, the association of PSA kinetics and PSA density ≥0.15 with reclassification persists at 5 years following diagnosis.
The authors identified 1,031 men with clinically low-risk prostate cancer prospectively enrolled on active surveillance at the University of California between 2000 and 2016. Biopsy reclassification was defined as Gleason Grade Group 2 or greater on subsequent biopsy.
Factors associated with risk of biopsy reclassification at first surveillance biopsy and 1 to 3, 3 to 5, and 5 to 10 years after enrolment were identified through multivariable Cox proportional hazards regression models, adjusting for clinicodemographic factors, Prostate Imaging Reporting and Data System (PI-RADS) score, and genomic testing.
Multivariable analysis revealed that biopsy reclassification correlated with PSA density ≥0.15 (hazard ratio [HR], 3.37, 95 percent confidence interval [CI], 1.83–6.21), percentage of biopsy cores positive (HR, 1.27, 95 percent CI, 1.05–1.54), and high genomic score (HR, 2.81, 95 percent CI, 1.21–6.52) at first surveillance biopsy and at 1 to 3 years, after adjustment.
PSA density ≥0.15 (HR, 2.36, 95 percent CI, 1.56–3.56) and PSA kinetics (HR, 2.19, 95 percent CI, 1.43–3.34) were also associated with reclassification at 3 to 5 years. However, a PI-RADS score of 4–5 did not correlate with biopsy reclassification at any time point.
“Few validated clinical tools currently exist to standardize the frequency of biopsies for men on active surveillance for low risk prostate cancer,” the authors noted.