Editor's Commentary - Bone scan overuse in staging of prostate cancer: An analysis of a Veterans Affairs cohort

BERKELEY, CA (UroToday.com) - Low and intermediate risk prostate cancer (CaP) is at low probability for having bone metastasis at the time of diagnosis.

The AUA guidelines recommend considering an initial bone scan for patients with one or more of the following; PSA≥20ng/ml, clinical stage T3a or higher, Gleason score ≥8, or bone pain. In Urology, Dr. Roland Palvolgyi and colleagues from UCLA evaluated the predictors for bone scan utilization among a cohort of patients in the Veterans Affairs health system.

A total of 1,598 men were identified using the California Cancer Registry with a new diagnosis of CaP between 1998 and 2004. These patients were diagnosed at the Greater Los Angeles and Long Beach VA Medical Centers. Clinical, demographic and pathologic variables were recorded. Mean age at diagnosis was 67.3 years and 44% were Caucasian, 43% without any comorbidities. Staging characteristics included PSA <20ng/ml in 80%, clinical stage cT2a or less in 63%, and Gleason score ≤6 in 54%. They found that 856 of 1,598 men underwent bone scans (54%). Of these, 519 men had low-risk CaP and 132 (25%) underwent bone scans. Among the 470 men with high-risk CaP, 398 (85%) underwent bone scans. After the year 2000, there was a 16% absolute reduction in bone scan use among men with low-risk CaP from 36% in 1998-2000 to 20% in 2001-2004. In univariate analysis, they found that factors associated with more likely use of bone scanning included younger age, greater PSA level, greater clinical stage, greater Gleason score and earlier year of diagnosis. In multivariate analysis, bone scan use for the entire cohort was lower for advancing age, black race, and year of diagnosis compared with us in men younger than 55 years and Caucasian race. Increasing PSA (≥10ng/nl), clinical stage ≥cT2c, Gleason score (≥7), and evaluation at the Long Beach VA Medical Center were independently associated with a greater odds of bone scan use than a PSA level <10ng/ml, clinical stage of cT1c or less, Gleason score ≤6, and Greater Los Angeles VA Medical Center, respectively. The researchers identified 96 positive bone scans from the 856 performed. No patient of the 132 with low risk CaP and 90 (24%) of the 382 men with high-risk CaP who underwent bone scans had a positive finding. Multivariate analysis for bone scan positivity revealed that a PSA ≥20ng/ml, ≥stage cT3a, Gleason score (4+3, and ≥8) were independently associated with a greater odds of bone scan positivity than the converse parameters. For the entire cohort, probabilities of bone scan use and positivity stratified by clinical parameters found that the probability of bone scan use was 43%, 58%, and 93% for cT1, cT2, and ≥cT3 disease, respectively. The corresponding probabilities of positivity were 2%, 7%, and 29%, respectively. Bone scan use was 40% for patients with Gleason score ≤6, for a 1% probability of it being positive. Bone scan use was 81% for patients with Gleason score ≥8, for a 26% probability of it being positive. For a PSA >20ng/ml, bone scan use was 89% and positivity rate was 23%.

These data confirm that bone scans are overused in the clinical setting.

Palvolgyi R, Daskivich TJ, Chamie K, Kwan L, Litwin MS


Urology. 2011 Jun;77(6):1330-6

PubMed Abstract
PMID: 21492911

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