The Risks of Prostate Cancer Detection by Transrectal Ultrasound Guide Biopsy in Thai Men with Abnormal Prostatic-Specific Antigen or Abnormal Digital Rectal Examination
SUNAI LEEWANSANGTONG, M.D.*, SAMRERNG RATANARAPEE, M.D.**, SUCHAI SOONTRAPA, M.D.* ANUPAN TANTIWONG, M.D.*, CHAIYONG NUALYONG, M.D.*,
Affiliation : *Division of Urology, Department of Surgery, **Department of Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand.
Objective : To determine the risks of prostate cancer detection in Thai men with
abnormal prostatic-specific antigen (PSA) or abnormal digital rectal examination (DRE).
Materials and Methods : One hundred and forty four Thai men with abnormal PSA or
abnormal DRE or both were biopsied at the prostate gland with the use of transrectal
ultrasound guide biopsy (TRUSBX). The risks of prostate cancer detection were evaluated.
Results : Mean age was 65.7 years old (S.D. = 9.88). The risks of positive biopsy
according to the PSA levels of 0-4 ng/ml, 4.1-10 ng/ml, I 0.1-20 ng/ml, 20.1-50 ng/ml,
50.1-100 ng/ml and more than 100 ng/ml were 6.25 per cent, 6.67 per cent, 10.8 per cent,
33.3 per cent, 60 per cent and 100 per cent, respectively. The risks of positive biopsy
according to DRE appearances of total hard consistency, nodule, induration and benign
prostatic hyperplasia were 57.1 per cent, 23.5 per cent, 34.6 per cent and 10 per cent,
respectively. Of 144 men, 32 had adenocarcinoma of prostate. Radical prostatectomy was
performed on 15 patients with clinically localized disease. Ten patients (66.6%) had free
margin on their pathological specimens and 6 ( 40%) had organ confined disease.
Conclusion : PSA testing alone or DRE alone is not a perfect test to diagnose
prostate cancer since prostate cancer may present in men with normal PSA or men with
no suspicious cancer DRE. For early detection of prostate cancer, both PSA testing and
DRE need to be performed. When either PSA testing or DRE or both is abnormal, TRUSBX
should be carried out.
Keywords : Prostate, Prostatic Carcinoma, Prostatic-Specific Antigen
