[Digital rectal examination, transrectal ultrasonography and prostate specific antigen for diagnosis of prostate cancer in clinical urological practice-detection of impalpable cancer].

OBJECTIVE: The clinical usefulness of multimodality detection for prostate cancer by digital rectal examination (DRE), transrectal ultrasonography (TRUS) and serum PSA determination (PSA) was evaluated in this retrospective study. PATIENTS AND METHODS: A total of 1344 symptomatic male patients who underwent DRE, TRUS and PSA in our outpatient clinic were studied. Prostate biopsies were performed when at least one diagnostic test was positive. RESULTS: Of 1344 patients, 436 (32.4%) had positive test results. Among 403 patients who underwent biopsy, 121 patients (30.0%) were found to have prostate cancer. The overall cancer detection rate was 9.0%. Among the 121 cancer patients, if examination had been carried out using only one or two tests, cancer would have not been detected in 22 patients (18.2%) by DRE alone, 27 patients (22.3%) by TRUS alone, 18 patients (14.9%) by PSA alone, 12 patients (9.9%) by a combination of DRE and TRUS, and 6 patients (5.0%) by a combination of DRE and PSA. Among the 121 patients with cancer, 22 (18.2%) had impalpable cancer. Impalpable cancer was more likely to be localized (77.3%) than palpable cancer (28.3%, p < 0.001) and more likely to be well or moderately differentiated (72.7%) than palpable cancer (41.4%, p = 0.008). CONCLUSION: This study confirmed the need for multimodality detection using DRE, TRUS and PSA as complementary methods in order to minimize decrease in cancer detection. In particular, impalbable cancers not detectable by DRE were detected and were revealed to be more likely to be localized and amenable to curative therapy. These results therefore underscore the importance of multimodality detection for early diagnosis of prostate cancer in urological practice.