A study on staging bone scans in newly diagnosed prostate cancer.

OBJECTIVE

This study aimed to evaluate the role of bone scan as a staging investigation in newly diagnosed untreated prostate cancers.

MATERIALS AND METHODS

Bone scan results in patients with newly diagnosed prostate cancer were reviewed and correlated with clinical stage, prostate-specific antigen (PSA) and Gleason scores from the biopsy specimen.

RESULTS

In all, 124 patients fulfilled inclusion criteria with an age range of 51-94 (mean 72.3) years. Pre-biopsy PSA ranged from 2.2 to 5,864 with a median of 21.1 ng/ml. Clinical stage was T0-T1c 14.5%, T2a 41.9%, T2b 17.7%, T3 16.9%, and T4 9%. A Gleason score of 7 was found in 31%. Four patients' samples were not suitable for Gleason scoring. Twenty patients (16.1%) had a positive bone scan with a mean age of 79.4 years (median 83). Two patients with PSA<20 ng/ml were positive. Of the 44 scans performed in the patients with PSA<or=20 ng/ml, clinical stage<T4 and Gleason sum<or=7 (with the major Gleason<4), none was positive. The above criteria give a 100% negative predictive value for avoiding bone scans as a staging investigation.

CONCLUSIONS

Staging bone scan can be safely omitted in patients with a clinical stage of <T4, PSA level of <or=20 ng/ml and a Gleason score of <or=7 (with major Gleason pattern<4) unless the symptoms are suggestive of metastasis.