Is it suitable to eliminate bone scan for prostate cancer patients with PSA ≤ 20 ng/mL?

PURPOSE: We evaluated the relationship between bone metastasis (BM) and clinical or pathological variables, including the serum prostate-specific antigen (PSA) concentration. METHODS: This retrospective study included 579 consecutive patients with newly diagnosed prostate cancer (Pca) who underwent a bone scan study at our institution between 2002 and 2010. We used receiver operating characteristics curves to evaluate accuracy of bone metastasis between serum PSA 10 and 20 ng/mL. RESULTS: A positive bone scan result was found in 83 men (14.3%) with PCa. However, 27 men (4.6%) with serum PSA between 10 and 20 ng/mL, 29/579 men (5.0%) with GS ≤ 7, and 21/83 (25.3%) with serum PSA ≤ 20 ng/mL and Gleason score (GS) ≤ 7 had positive bone scans. In the logistic regression analyses, clinical T stage (odds ratio [OR] = 3.26; 95% CI, 2.29–4.33; P = 0.021), GS (OR = 3.41; 95% CI, 2.91–4.63; P = 0.019), and serum PSA (OR = 8.37; 95% CI, 3.91–19.21; P < 0.001) were predictive factors of detecting the BM. When the serum PSA concentration ≤20 ng/mL and GS ≤ 7, AUC value of bone scans for the detection of BM was 0.640 (P = 0.020; 95% CI, 0.563–0.717). With serum PSA at 10 ng/mL and GS ≤ 7, the AUC values of bone scans were 0.828 (P < 0.001; 95% CI, 0.773–0.883). CONCLUSIONS: Bone scans might be necessary in men with serum PSA between 10 and 20 ng/mL. New guidelines for eliminating bone scans in patients with newly diagnosed Pca are needed, especially in Asians.