DNA ploidy and PTEN protein expression as biomarkers for predicting aggressive disase in prostate cancer patients under active surveillance

Current risk stratification tools for prostate cancer patients under active surveillance (AS) may inadequately identify those needing treatment. A retrospective study at Oslo University Hospital evaluated DNA ploidy (by image cytometry) and PTEN protein expression (by immunohistochemistry) as potential biomarkers to predict aggressive disease in AS patients. The combined DNA ploidy and PTEN (DPP) status at diagnosis was associated with treatment-free survival, with a HR for DPP-aberrant versus DPP-normal tumors of 2.12 (p<0.0001) in univariable analysis and 1.94 (p<0.0001) in multivariable analysis. Integration of DNA ploidy and PTEN status in the Cancer of the Prostate Risk Assessment score improved risk stratification (c-index difference 0.025; p=0.0033). Among treated patients, those with DPP-aberrant tumors had a significantly higher likelihood of treatment failure (HR 2.01; p=0.027). The authors conclude that DNA ploidy and PTEN could serve as additional biomarkers to identify AS patients at increased risk of developing aggressive disease, enabling earlier intervention for nearly 50% of the patients who will eventually receive treatment with current protocols.