Correlation Of Transrectal Ultrasound Findings With Histology In The Detection Of Prostatic Lesions

Abstract

Introduction: Prostate cancer is the most common male cancer, and the third leading cause of cancer death in men. The presence of this common disease among Kenyan men is well recognised. Over the past five decades, there has been a continued increase in mortality due to prostate cancer, despite all the different options of treatment at the disposal of the Urologist. The current approach to effective therapy for prostate cancer, is early diagnosis of the disease, still localised within the prostate. This can be achieved through a cancer screening test that remains faithful to the main goal of reduction of mortality. It is still yet to be established whether the present screening techniques, including digital rectal examination (ORE), prostate specific antigen (PSA), transrectal ultrasound (TRUS), and random ultrasonically guided multiple prostatic biopsies, are proved to provide real benefit in reduction of mortality. The value of TRUS in imaging the prostate gland, and its use in guiding prostate biopsies, is widely accepted as an effective examination for men to undergo, for early detection of prostate cancer. Objectives: This study aimed to demonstrate the transrectal sonographic diagnosis in patients referred for the examination, due to abnormal clinical findings and serum PSA values. The study will also evaluate the number of TRUS lesions appearing to be malignant, that confirm as such on histological assessment. Methodology: This was a prospective study, conducted at the Aga Khan University Hospital. It was carried out for a period of eight months on all male patients, referred to the Department of Diagnostic Radiology, with clinical suspicion of Cancer of prostate (CAP) due to abnormal ORE and/or abnormal PSA values. These patients underwent a TRUS-guided prostate biopsy, and the cores of gland tissue were subjected to histological analysis at the AKUH Histology department. Prior to carrying out the biopsy, the prostate gland was interrogated by a 7MHz transrectal probe. The imaging features and sonographic impression, including the histological diagnosis were documented on a data sheet. Results: A total of eighty-seven (87) patients were recruited. Fifty-eight patients were found to have BPH at histoloqical analysis of the TRUS-guided biopsy samples. Twenty-seven patients were found to have CAP. The age range was from 50 to 91 years; with a mean of 66.9 and median of 67. Majority of the patients (39.1 %), were in the 61-70 years age bracket. Cancer of prostate was found to increase with advanced age. The peak age for CAP was 61 to 70 years. The peak age for BPH was 50 to 60 years. The majority of patients (61.6%), had serum PSA levels of over 10ng/ml. Levels for the majority (92.6%) of cases found to have CAP at histology, were above 10ng/ml. Transrectal sonographic features suggestive of CAP comprised 75% of cases with serum PSA levels above 10ng/ml. Forty-six (78%) cases with sonographic features of BPH confirmed as such at histology. Among patients with sonographic features of CAP, 19 (67.9%) confirmed as such at histology. Conclusions: The majority of patients referred for TRUS-guided biopsy of the prostate due to clinical suspicion of CAP, turned out to have BPH as confirmed by histology. Transrectal ultrasound has a moderate sensitivity in the detection of malignant prostatic lesions, with a significant rate of false-negative detection for CAP.