When To Perform Bone Scan In Patients With Newly Diagnosed Prostate Cancer: Validation Of Available Guidelines, Risk Stratification Tool Proposal

- Prostate cancer (CaP) patients often undergo a routine bone scan as part of their metastatic evaluation at the time of diagnosis. Most consensus recommendations suggest obtaining bone scans only in patients with risk characteristics suggesting reasonable utility for this test. However, according to a paper by Dr. Alberto Briganti and colleagues in an online publication in European Urology these guidelines are neither based upon contemporary patient cohorts nor have they been externally validated. These investigators sought to externally validate and test the performance characteristics of the current EAU, AUA, AJCC, and NCCN recommendations on the need for baseline staging bone scans in a large cohort of men with newly diagnosed CaP.



Between 2003 and 2008, 853 consecutive patients with newly diagnosed CaP had complete clinical and pathological data available for interpretation. All patients were also staged with Tc 99m MDP scintigraphy performed regardless of risk characteristics. Uni- and multivariate analysis was performed and the area under the curve (AUC) was estimated in the context of the various recommendations. In general, most of the recommended guidelines suggest a bone scan for patients with a Gleason score >7, a PSA >20ng/ml, or clinical stage T3-4 disease.



The baseline bone scan was negative in 81.5% of the 853 patients and in the remaining 158 it was unequivocally positive in 18 men or equivocal in 140. Further evaluation of the equivocal findings by MRI or CT confirmed the presence of bone metastasis in 6 patients (4.3%) and excluded bone metastasis in the remaining 136 (95.7%). In sum, 24 of 853 men (2.8%) had confirmed bone metastasis. In multivariate analysis, PSA at diagnosis, clinical stage, and biopsy Gleason score were the only independent predictors of bone metastasis. The rate of bone metastasis in patients according to guideline recommendations ranged from 12.7-15.3% compared with 0.7-0.9% in the remaining patients. In patients with Gleason score