Can initial prostate specific antigen determinations eliminate the need for bone scans in patients with newly diagnosed prostate carcinoma? A multicenter retrospective study in Japan

BACKGROUND. The objective of the current study was to assess rigorously whether serum prostate specific antigen (PSA) determination can eliminate the need for bone scans in Japanese patients with newly diagnosed prostate carcinoma with serum PSA levels ≤ 10 ng/mL. METHODS. A retrospective assessment of 1294 patients with newly diagnosed, untreated prostate carcinoma was conducted at the authors' institutions. All patients underwent a bone scan, serum PSA measurement, and core needle biopsy of the prostate. The receiver operating characteristic curve for identifying a positive bone scan based on serum PSA levels and a decision tree were analyzed to determine the expected 10-year cumulative cost and disease specific survival rate. Two competing strategies were used: PSA alone and PSA plus baseline bone scan. For the PSA-alone strategy, a baseline bone scan was performed only when the patient had a serum PSA level > 10 ng/mL. RESULTS. The proportion of positive bone scans in patients with serum PSA levels ≤ 10.0 ng/mL was 1.33%. The area under the receiver operating characteristic curve was 0.870. Patients with a Gleason Grade ≥ 3 tumors or with a Gleason score ≥ 7 had a higher proportion of positive bone scans. The 10-year disease specific survival rates with the PSA-alone strategy and the PSA-plus-bone-scan strategy were the same. The PSA-alone strategy was minimally cost effective, with a savings of $16.00 (U.S.) in the cumulative net cost per patient over the PSA-plus-bone-scan strategy. CONCLUSIONS.The current results suggest that baseline bone scans can be eliminated in patients with newly diagnosed prostate carcinoma in Japan who have serum PSA levels ≤ 10 ng/mL. Apparently, it is possible to omit baseline bone scans for patients with a Gleason Grade ≤ 2 tumors or with a Gleason score ≤6.