PROSTATE-SPECIFIC ANTIGEN DETECTED PROSTATE-CANCER - PATHOLOGICAL CHARACTERISTICS OF ULTRASOUND VISIBLE VERSUS ULTRASOUND INVISIBLE TUMORS

Most studies examining the issue of 'early detection of prostate cance r' advocate the combined use of serum prostate-specific antigen (PSA) and digital rectal examination (DRE). As a result, a significant numbe r of new prostate cancers are diagnosed on the basis of an elevated se rum PSA when the DRE is unremarkable. The purpose of this study is to determine if the PSA-detected tumors that are visible on transrectal u ltrasound (TRUS) have the same pathological characteristics as PSA-det ected tumors that are invisible on TRUS. One hundred and ninety-four p atients with an elevated serum PSA concentration and nonpalpable prost ate cancer who underwent radical retropubic prostatectomy (RRP) at our institution between March 1988 and December 1991 were reviewed. The p atients were divided into two groups: 97 (50%) had no identifiable les ion on TRUS, and 97 (50%) had at least one hypoechoic area consistent with adenocarcinoma of the prostate. The pathological characteristics of the RRP specimens from the two groups were compared. There was no s ignificant difference in the age (p = 0.14) or the preoperative serum PSA values (p = 0.18) between the groups. Also, there was no significa nt difference between the groups with regard to tumor volume (p = 0.89 ), focality of the cancer (p = 0.43), Gleason score (p = 0.81), DNA pl oidy status (p = 0.96), pathological stage (p = 0.92), surgical margin involvement (p = 0.27), and tumor location (p = 0.64). These findings suggest that the clinical TNM staging system for prostate cancer may be simplified by eliminating the distinction between PSA-detected canc ers visible on TRUS and PSA-detected cancers not visible on TRUS. As a result, all nonpalpable, PSA-detected cancers could be classified as stage T1c in the TNM system, irrespective of TRUS findings. In the Whi tmore-Jewett staging system, all PSA-detected cancers are classified a s stage B-0.