Which patients with newly diagnosed prostate cancer need a computed tomography scan of the abdomen and pelvis? An analysis based on 588 patients

Objectives. Although a computed tomography (CT) scan of the abdomen and pel vis is often recommended as part of the staging evaluation for newly diagno sed prostate cancer, most scans are negative for metastases. We hypothesize d that biopsy Gleason score, serum prostate-specific antigen (PSA) levels, and clinical stage could predict for a positive CT scan and that a low-risk group of patients could be identified in whom CT might be omitted. Methods, All patients who had both pathologic review of their prostate canc er biopsies and abdominopelvic CT scans at our institution between January 1990 and May 1996 were studied. Gleason score, PSA, and stage were evaluate d by univariate (chi-square) and multivariate (logistic regression) analyse s for their ability to predict for a positive CT. Results, Of 588 patients, 41 (7%) had a positive CT scan. Multivariate anal ysis showed Gleason score, PSA, and clinical stage to be significant indepe ndent predictors of a positive CT scan, all P < 0.001. The odds ratios for a positive CT scan were 6.17 (95% confidence interval [CI] = 1.58 to 24) fo r Gleason score 8 to 10 versus 2 to 6; 2.25 (CI = 1.24 to 4) for PSA greate r than 50 versus 0 to 15 ng/mL; 2.08 (CI = 1.70 to 3.21) for Stage T2c-T4 v ersus T2b or lower. All 244 patients with Gleason score 2 to 7, PSA 15 ng/m L or less, and clinical Stage T2b or less had negative CT scans. Of the oth er 174 patients with a Gleason score of 2 to 7, 8 (5%) had a positive CT sc an. Of the 126 patients with a Gleason score of 8 to 10, 28 (22%) had a pos itive CT scan. Conclusions. Gleason score, PSA, and clinical stage were independent predic tors for a positive CT scan of the abdomen and pelvis in patients with newl y diagnosed prostate cancer. In this cost-conscious era, we can decrease ex penditure by obviating the need for a CT scan in low-risk patients (clinica l Stage T2b or less, Gleason score 2 to 7, and PSA 15 ng/mL or less). A CT scan should be considered in all other patients. (C) 1999, Elsevier Science Inc.