|Year : 2010 | Volume
| Issue : 2 | Page : 59-61
Transrectal ultrasound findings in patients with advanced prostate cancer
M Ahmed, HY Maitama, A Bello, GD Kalayi, HN Mbibu
Division of Urology, Department of Surgery, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria
|Date of Web Publication||24-Mar-2011|
Division of Urology, Department of Surgery, Ahmadu Bello University Teaching Hospital, Zaria, Kaduna State
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Objectives : The objective is to determine transrectal ultrasound (TRUS) findings and their relevance in the diagnosis of prostatic cancer among patients with abnormal digital rectal examination (DRE) and elevated PSA.
Materials and Methods : This was a prospective study of 131 patients suspected to have advanced prostate cancer based on clinical presentation, abnormal DRE and elevated PSA (>10 ng/ml), who were evaluated with TRUS prior to prostatic biopsy and the findings correlated with the histologic outcome.
Results : The mean prostate size by TRUS was 66.8 g with a range of 15-219 g. The majority of patients with hypoechoic nodules 56.3% (45 of 80) had a malignant histology and the yield was higher among those with both hypoechoic nodules and prostatic capsule invasion 25 (31.3%). Cancer detection in those with mixed echogenicity was next in frequency 33.8% (27 of 80). All the prostates with hyperechoic pattern and most of those with isoechoic appearance had benign histology.
Conclusion : Though TRUS findings generally have a low specificity for prostate cancer, the specificity of TRUS findings is probably higher in advanced prostate cancer.
Keywords: Prostate, Advanced cancer, transrectal, ultrasound
|How to cite this article:|
Ahmed M, Maitama H Y, Bello A, Kalayi G D, Mbibu H N. Transrectal ultrasound findings in patients with advanced prostate cancer. Ann Nigerian Med 2010;4:59-61
|How to cite this URL:|
Ahmed M, Maitama H Y, Bello A, Kalayi G D, Mbibu H N. Transrectal ultrasound findings in patients with advanced prostate cancer. Ann Nigerian Med [serial online] 2010 [cited 2021 Jan 24];4:59-61. Available from: https://www.anmjournal.com/text.asp?2010/4/2/59/78274
| Introduction|| |
Transrectal ultrasound (TRUS) is one of the modalities for the evaluation of a patient with suspected carcinoma of the prostate. ,, TRUS is like an extension of the urologist's finger. It should be noted that ultrasonography is operator dependent. The knowledge and experience of the operator significantly affects the outcome.  Currently, the most widely used probe is a 7-MHz (range 4-8 MHz) transducer within an endorectal probe, which can produce images in both the sagittal and axial planes.  Scanning begins in the axial plane, and the base of the prostate and seminal vesicles are imaged first; some amount of urine in the bladder facilitates the examination. Carcinoma of the prostate is commonly hypoechoic (71%), but may be isoechoic (28%) or hyperechoic (1%). ,, These features are non-specific and may occur in benign prostatic diseases. , Cancer may also be suggested by asymmetry and capsular distortion. Some cancers can only be detected on systematic biopsies in an apparently normal looking prostate. ,,
The limitations of TRUS in prostate cancer detection are the following. Most hypoechoic lesions found on TRUS do not have cancer, and 50% of nonpalpable cancers <1 cm in greatest dimension are not visualized by ultrasound. , The potential roles of TRUS in the diagnosis of carcinoma of the prostate include: to identify prostatic lesions suspicious of harboring cancer, to ensure accurate wide area sampling of prostatic tissue, accurate measurement of prostatic volume, local staging and diagnosis of other prostatic diseases (prostatitis, tuberculosis, schistosomiasis and calculi) and diagnosis of concurrent intravesical lesions. 
| Materials and Methods|| |
This was a prospective study that was carried out over a period of 1 year in the Division of Urology, Department of Surgery of Ahmadu Bello University Teaching Hospital, Zaria, Nigeria. Approval for the study was obtained from the hospital ethical and scientific committee before the commencement of the study. Only the patients who willingly consented after being duly informed were included in the study. This study was based on a routine investigative procedure for all patients with suspected carcinoma of the prostate.
Patients seen at the urology outpatient clinic with the suspicion of advanced carcinoma of the prostate, based on clinical presentation, abnormal DRE findings and elevation of PSA >10 ng/ml, were included. They all had TRUS using ATL, APOGEE 800-PLUS ultrasound machine with a 7.5-MHz transrectal multiplanar probe. Data obtained were analyzed using Statistical Package for Social Sciences (SPSS) computer software. The results were displayed in tables and charts.
| Results|| |
A total of 131 patients met the inclusion criteria and were enrolled in the study. The mean age was 66.3 years with a range of 49-91 years. The age interval 60-69 years accounted for most of the patients 59 (45%). The age distribution is shown in [Figure 1].
The commonest reason for presentation was due to lower urinary tract symptoms (LUTS) in 87 (66.4%) patients. The other symptoms were as shown in [Table 1].
The mean PSA was 33.9 ng/ml (range 10.2-120 ng/ml), with a standard deviation (SD) of 19.33. All the patients had TRUS. The mean size of prostate measured by TRUS was 66.8 g with a range of 15-219 g and showed variable features as shown in [Table 2]. It was found that majority of patients with hypoechoic nodules 56.3% (45 of 80) had a malignant histology and the yield was higher among those with both hypoechoic nodules and breached prostatic capsule 25 (31.3%). Cancer detection in other echopatterns was as shown in [Table 3].
All the prostates with hyperechoic pattern and most of those with isoechoic appearance had benign histology.
| Discussion|| |
Prostate cancer is now increasingly diagnosed at an early stage following the introduction of the biomarker Prostate specific antigen and the possibility of accurate biopsy guided by state of the art TRUS facility. ,, In the developing countries, late clinical disease is still the commonest mode of presentation. ,2,
In this study, majority of the patients (45%) were mainly in their seventh decade (60-69 years) of life with a mean age was 66.3 years. This is similar to the mean age reported by DN Osegbe (68 years) and by Dawam and colleagues (66.3 years) in their studies on Nigerians. , The mean prostate size was 66.8 g with a range 15-219 g; this may not contribute much in differentiating benign from malignant prostate. The ultrasound features were mostly of mixed echogenicity (39.7%), followed by hypoechoic nodules (22.1%).  Cancer was detected more often in patients with TRUS findings of hypoechoic nodules (56.3%). Though this result may suggest a higher positive predictive value for cancer using TRUS findings, studies have shown that they generally lack specificity with a low positive predictive value of <28%. ,, The recruitment of patients thought to have advanced disease in this study probably accounts for the high specificity found. All the prostates with hyperechoic and most of those with isoechoic appearance had benign histology, but this is not surprising because findings from other studies show that they account for only 1-14% of prostate caner.  Ellis and co-workers  noted that 37.6% of the cancers were diagnosed in isoechoic areas of the prostate, while Flanigan and associates  found that only 18% of 855 sonographically suspicious quadrants actually contained cancer on biopsy, whereas 65% of normal looking quadrants contained cancer and 17% of hypoechoic areas yielded cancer. This has made TRUS findings an unreliable tool in prostate cancer screening, while on the other hand, it has markedly improved prostate biopsy guidance.
| Conclusion|| |
Though TRUS findings generally have a low specificity for prostate cancer, the finding from this study of higher cancer yield among patients with hypoechoic nodules and prostate capsular invasion suggests a higher yield with advanced disease. Thus, the specificity of TRUS findings is probably higher in advanced prostate cancer.
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[Table 1], [Table 2], [Table 3]