Risk prediction tool for grade re‐classification in men with favourable‐risk prostate cancer on active surveillance

Objective To create a nomogram for men on active surveillance ( AS ) for prediction of grade re‐classification ( GR ) above Gleason score 6 (Grade group >2) at surveillance biopsy. Patients and Methods From a cohort of men enrolled in an AS programme, a multivariable model was used to identify clinical and pathological parameters predictive of GR . Nomogram performance was assessed using receiver operating characteristic curves, calibration, and decision curve analysis. Results Of 1 374 men, 254 (18.50%) were re‐classified to Gleason ≥7 on surveillance prostate biopsy. Variables predictive of GR were earlier year of diagnosis [≤2004 vs ≥2005; odds ratio ( OR ) 2.16, P < 0.001], older age ( OR 1.05, P < 0.001), higher prostate‐specific antigen density [ OR 1.19 (per 0.1 unit increase), P = 0.04], bilateral disease ( OR 2.86, P < 0.001), risk strata (low‐risk vs very‐low‐risk, OR 1.79, P < 0.001), and total number of biopsies without GR ( OR 0.68, P < 0.001). On internal validation, a nomogram created using the multivariable model had an area under the curve of 0.757 (95% confidence interval 0.730–0.797) for predicting GR at the time of next surveillance biopsy. Conclusion The nomogram described is currently being used at each return visit to assess the need for a surveillance biopsy, and could increase retention in AS .