Correlation between Prostate Specific Antigen and Prostate Biopsy Gleason Score

Abstract

Background: Prostate Specific Antigen (PSA) is a commonly used marker in prostate cancer management. Gleason grading is one of the most powerful predictors of prostatic biological behaviour. PSA, when combined with the Gleason score and clinical stage, improves the prediction of the pathological stage for prostate cancer. Objectives: To assess the degree of correlation between PSA level and Gleason score as well as determine the likelihood of aggressiveness of prostate cancer using Gleason score as a parameter. Methods: A cross-sectional prospective study was conducted among 234 consecutive consenting patients presenting to the Urology Out-Patient Clinic between April 2015 and March 2018. Serum PSA was done and patients with values above 4ng/ml and/or abnormal Digital Rectal Examination (DRE) were selected to have a prostate biopsy. The sample was histologically analysed with Gleason score recorded for those with prostate cancer. Gleason score was then correlated with PSA levels. Results: The mean age for prostate cancer patients was 71.3±8.7 years. The mean PSA for patients with prostate cancer was 52.3±37.5ng/ml (Confidence Interval = 46.1-58.6) with p<0.001. About 18.2% of histologically confirmed prostate cancer cases had Gleason score 8-10 implying a high level of tumour aggressiveness. There is a positive correlation between PSA and Gleason score with R-value 0.590 indicating a good degree of correlation. Conclusion: There is a good degree of a positive correlation between PSA level and Gleason score, as well as a high level of aggressiveness of prostate cancer in Umuahia.