PATIENTS WITH ABNORMAL ULTRASOUND OF THE PROSTATE BUT NORMAL DIGITAL RECTAL EXAMINATION SHOULD BE CLASSIFIED AS HAVING CLINICAL STAGE T2 TUMORS

Abstract

The current TNM staging system classifies prostate tumors with abnormal transrectal ultrasound but normal digital rectal examination as clinical stage T2. However, most urologists consider these tumors as clinical stage T1c due to the perceived inaccuracy of transrectal ultrasound in clinical staging. To determine the role of transrectal ultrasound in the clinical staging of prostate cancer we evaluated the pathological stage and disease-free survival of patients undergoing radical prostatectomy who had tumor detected by needle biopsy because of elevated serum prostate specific antigen with or without transrectal ultrasound abnormalities. Between 1991 and 1996, 738 patients underwent radical retropubic prostatectomy as monotherapy for clinically localized prostate cancer. Patients were classified into group 1-normal digital rectal examination and transrectal ultrasound (138), group 2-normal digital rectal examination but abnormal transrectal ultrasound (366) and group 3 -abnormal digital rectal examination (234). We compared pathological parameters and disease-free-survival among the 3 groups. Tumors were organ confined in 61%, 42% and 41% of patients in groups 1, 2 and 3, respectively (p = 0.0001). Overall disease-free survival was 80% with a mean followup of 68 months. Disease recurred in 8%, 22% and 25% of patients in groups 1, 2 and 3, respectively (p = 0.007). Group 1 had better disease-free survival compared to groups 2 and 3 (p = 0.003 and p = 0.002, respectively), and there was no difference in disease-free survival between groups 2 and 3 (p = 0.39). We provide evidence to support the use of transrectal ultrasound findings in the clinical staging system for prostate cancer. Patients with normal digital rectal examination, elevated serum prostate specific antigen and abnormal transrectal ultrasound should be considered as having clinical stage T2 disease.