Patterns of primary staging for newly diagnosed prostate cancer in the era of prostate specific membrane antigen positron emission tomography: A population-based analysis.

Abstract

There has been a growing body of evidence highlighting the improved sensitivity and specificity for prostate specific membrane antigen (PSMA) positron emission tomography (PET) in advanced prostate cancer imaging. We aimed to assess prostate cancer staging practice patterns in Australia using population-based data. We extracted data on men diagnosed with prostate cancer between October 2016 and December 2018 from the Prostate Cancer Outcomes Registry-Victoria (PCOR-Vic). We evaluated trends and comparisons between patients receiving PET/CT (with or without conventional imaging (CImg)), and CImg alone, and analysed imaging modality as predictor of clinical regional node positive disease (cN1 vs cN0/X), metastatic disease (cM1 vs cM0/X), and treatment received. In total, 6139 patients in the registry had either a staging PET scan (n=889, 14%), CImg without PET scan (n=2464, 40%), or no recorded PET or CImg (n=2786, 45%). The proportion of allimaged patients who received staging PET increased from 19% to 36% from the first to last three-month period, and in the high-risk category the increase was 23-43%. After adjustment for grade group, PET vs CImg-only patients were observed to have a higher proportion of cN1 disease (OR=2.46, 95% CI: 1.90-3.20) but not cM1 disease (OR=1.10, 95% CI: 0.84-1.44). Our registry data highlights the rapid uptake of PET imaging, particularly in high-risk disease. Based on this data, we highlight the increased diagnosis of nodal disease, thus potentially optimizing patient selection prior to definitive treatment for prostate cancer.