Early Experience of Transperineal Prostatic Biopsy under Transrectal Ultrasound Guidance

Park, Seong Woon; Oh, Kil Hyun

Abstract

To evaluate the role of digital rectal examination(DRE), prostate specific antigen(PSA), transrectal ultrasound(TRUS) and prostate specific antigen density(PSAD) and the effectiveness of TRUS-guided perineal prostatic biopsy in the diagnosis of prostate cancer, the clinical data were reviewed from the 78 patients who were suggested to have prostate cancer with DRE, PSA or TRUS, and pathologically confirmed by TRUS-guided six systematic biopsy between May 1993 and February 1995. Of 78 patients, 15 patients(19.2%) had prostate cancer, 60 patients(76.9%) BPH, 2 patients (2.6%) chronic prostatitis and 1 patient(1.3%) prostatic metastasis from transitional cell carcinoma of the bladder. Only 2 of 15 cancers (13.3%) were localized cancer, while 10 of 15 cancers(66.7%) had distant metastasis. Although 35 patients received TURP among 60 patients with BPH, and their specimens were investigated pathologically whether prostate cancer was present, there was no prostate cancer. Of 34 patients whose PSA levels were below 10ng/ml, none had prostate cancer regardless of the results of DRE and TRUS. PSA had the highest sensitivity(100%) and DRE the highest specificity (79.4%) among the modalities. The positive predictive value of DRE, PSA and TRUS was 48.0%, 22.1% and 36.1% respectively. DRE and TRUS had 54.5% and 44.8% Positive predictive value in patients with elevated PSA level in contrast to 0% positive predictive value in patients with normal PSA level. Because 3 patients of prostate cancer with negative DRE and positive TRUS had elevated PSA level(>20ng/ml), the addition of TRUS to PSA and DRE was not helpful in early detection of prostate cancer. Although PSAD of prostate cancer group and non-prostate cancer group was 1.312+/-0.155(S.E.) and 0.279+/-0.036 respectively(p<0.05), we could not found any superiority of PSAD to PSA in early diagnosis of prostate cancer. In conclusion, these results suggest that PSA and DRE should be used as the first line modality in early diagnosis of prostate cancer, TRUS-guided prostatic biopsy may be considered as a confirmative modality in patients with elevated PSA level or abnormal DRE and the clinical.trials for standardization of the upper normal limit of PSA should be followed.