Predictability of PSA, DRE and TRUS for Detection of Prostatic Cancer in Considering the Non-surgical Treatment of BPH Patients

Kim, Tae Han; Lee, Jeong Gu; Cho, Jae Heung

Abstract

Recently, some forms of non-surgical treatment modalities for BPH such as microwave or laser induced hyperthermia have been available and its demand by patient is increasing. The advantage of these treatment is its out-patient basis of treatment(no admission & no anesthesia). However, it leaves no surgical specimens for the pathological examination and detection of stage A prostate cancer may be impossible. Therefore, early detection of prostatic cancer prior to the non-surgical treatment of BPH is considered important if there are any suspicious signs of prostate cancer from the results of prostate specific antigen (PSA), digital rectal examination (DRE), or transrectal ultrasound(TRUS). The aims of our study is to compare the predictability of the DRE, PSA, and TRUS in the detection of prostate cancer before planning to take non- surgical treatment of BPH. One hundred thirty three patients between 50 to 85 years old (mean age 67.9) with symptoms of prostatism were examined serum PSA, DRE and TRUS prior to the treatment of BPH and predictability for the detection of prostatic cancer by each test were analyzed. Of the 133 cases, 3 were diagnosed as inflammations, 1 as tuberculosis, 1 as infarct, 110 as nodular hyperplasia, 18 as prostate cancers. Positive predictability of each test were as followed: 59.3% of the patients with abnormal DRE, 57.7% of the patients with abnormal TRUS and, 34% of the patients with abnormal PSA level( > 10 ng/ml). For the 44 patients with abnormal PSA level( > l0 ng/ml) and, coexisting abnormalities on either TRUS or DRE, positive predictability was 72%. However, in the 26 patients with abnormal PSA( >10ng/ml) with normal findings at DRE and TRUS, only 2 patients have prostate cancer. Of the 17 patients showing abnormal findings at DRE and TRUS irrespective of PSA level, 15 patients(positive predictability of 90%) have prostate cancer. Of the 12 patients having abnormal DRE and TRUS with elevated PSA level(more than 10.0 ng/ml), all patients had cancer. Conclusively, cancer predictability of single application of these screening test was low. Positive predictability of the elevated PSA level above 10 ng/ml was low if there were no abnormalities at DRE and TRUS. However, if there were abnormalities at DRE and TRUS, predictability of cancer became high. It is suggested that, if there were no abnormalities found at DRE and TRUS, prostate needle biopsy seem to be necessary despite the normal level of PSA( < 4 ng/ml). For the gray zone of the PSA level( 4-10 ng/ml) with no suspicious findings at DRE and TRUS, careful observation with follow up PSA measurement could be suggested.