Bone scan overuse in staging of prostate cancer: an analysis of a Veterans Affairs cohort.

OBJECTIVES: To determine the use and subsequent yield of bone scan imaging in a contemporary Veterans Affairs (VA) cohort of men with prostate cancer. With contemporary widespread prostate-specific antigen (PSA) screening, more patients are being diagnosed with low- and intermediate-risk prostate cancer, reducing the need and yield of bone scan imaging.
METHODS: We retrospectively reviewed the charts of 1598 men diagnosed with prostate cancer from 1998 to 2004 at the Greater Los Angeles and Long Beach VA Medical Centers. We used univariate and multivariate analyses to measure the association between patient (age, race, and comorbidities) and tumor (PSA, clinical stage, Gleason grade) characteristics with bone scan use and subsequent positivity. We conducted the analysis for scans for the entire cohort and those with low and high risk of metastatic disease.
RESULTS: Of 519 men with low-risk disease, 132 (25%) underwent bone scan imaging, none with positive findings. On multivariate analysis for the entire cohort, younger age, Long Beach VA site, increasing PSA level (≥10 ng/mL), clinical stage (cT2 or greater), and Gleason score (≥7) were all positively associated with bone scan use; however, only PSA level ≥20 ng/mL, clinical stage cT3 or greater, and Gleason score ≥4 + 3 corresponded with positivity. A bone scan positivity rate of ≥10% was limited to men with clinical stage cT3 or greater, Gleason score of ≥8, or PSA level of ≥20 ng/mL.
CONCLUSIONS: Although decreasing in incidence with time, our results demonstrate extensive overuse of bone scan imaging among VA patients with low-risk prostate cancer. These patterns of overuse for men with low-risk cancer, yielding no positive findings, result in unnecessary patient anxiety and significant economic waste for the VA Healthcare System.