Evaluation of Serum Prostate Specific Antigen Levels to Differentiate Prostate Cancer from Benign Prostatic Hyperplasia

Abstract

The prostate gland is the male secondary sexual organ most commonly affected by benign or malignant neoplasm. Prostate cancer (Ca-P) is one of the most commonly diagnosed cancers in men and is now the third commonest cause of cancer death in western countries. The aim of the study was to evaluate the use of serum prostate-specific antigen levels in differentiating prostate cancer from benign prostatic hyperplasia. This study was carried out with 288 patients-benign prostatic hyperplasia (BPH) = 192 and carcinoma prostate-96) and the study population included the male patients above 50 years of age, who attended at the Department of Urology, Rajshahi Medical College Hospital (RMCH), Rajshahi, and different private clinics in Rajshahi City complaining irritative or obstructive lower urinary tract symptoms (LUTS) suspected as clinically prostate cancer or benign prostatic hyperplasia. Prostatic carcinoma was observed to be significantly higher from 80 years onwards, while BPH was common between 60 - 80 years (p = 0.00001). Data shows the validity or accuracy of the free/total ratio of serum PSA as a diagnostic test in differentiating prostatic carcinoma from BPH in patients with total PSA PSA levels between 4-10 ng/ml. The percentage of false positives was significantly higher when total PSA ratio was used to diagnose the disease compared to when free to total PSA ratio was used as a diagnostic tool (p<0.000001). The overall accuracy of total PSA was also significantly lower (61.45%) than that of free/total PSA (91.67%) (p<0.011526). Another study was conducted to investigate the prevalence of prostatic carcinoma is the outcome of several factors including improved awareness the general population of the significance of carcinoma of the prostate and progresses in diagnostic approaches. The PSA is a probable prostate cancer tumour marker, although it cannot distinguish prostate cancer from BPH solely. To assess the usefulness of ree, total, and free/total PSA ratios in differentiating BPH and prostate cancer has been studied under this research work. Here, 350 patients with symptoms of the lower urinary tract, such as frequent urination, urgency, reluctance, poor flow, incontinence and nocturia, excessively big or nodular prostate detected by digital rectal examination suspected for BPH or prostate cancer were studied in men aged 50 and older. Prostatic cancer was more prevalent in men aged 70-80, whereas BPH was more common in men aged 60-70 (p = 0.00032). Histopathology revealed 95 prostate cancer patients, 82 with PSA >4 ng/ml and 85 patients had f/t PSA ratio>0.16. BPH was found in 255 individuals. 139 BPH patients had total PSA >4 ng/ml and 245 BPH patients had f/t PSA ratio ≤0.16. Total PSA had sensitivity and specificity of 86.32% and 45.49%, respectively, lower than f/t ratio. The (positive predictive value) PPV and accuracy was significantly higher in f/t ratio than total PSA.