CORRELATION OF SERUM PROSTATE SPECIFIC ANTIGEN, GLEASON SCORE AND CLINICAL STAGE AMONG PATIENTS WITH ADENOCARCINOMA OF THE PROSTATE IN AHMADU BELLO UNIVERSITY TEACHING HOSPITAL (ABUTH) ZARIA: AN EIGHT (8) YEAR RETROSPECTIVE STUDY (JAN 2006 –DEC 2013)

Abstract

Introduction:During the past many years the availability of serum PSA as a screening tool has
encouraged its use to diagnose and estimate the prognosis of prostatic cancer. This
prognostication is usually done in conjunction with other prognostic indices like the Gleason
score and the clinical stage of the cancer. The aim of this study was to determine association
between serum prostatic specific antigen (PSA) concentration, the Gleason score and the clinical
stage among patients with prostate adenocarcinoma. Study Design: Retrospective, cross
sectional comparative study. Study Setting: Department of Pathology, Ahmadu Bello University
Teaching Hospital, Zaria. Study Period:January 2006 to December 2013.Methods: A total of
Two Hundred and Eleven (211) patients of age 35-100 years with biopsy proven prostatic
carcinoma were included. Histological slides of each patient were reviewed by using the Gleason
grading system. Pre-treatment serum prostatic specific antigen (PSA) concentration and Clinical
stage of the cancer were obtained from the patient’s case records in the Urology unit of the
hospital. Gleason score and clinical stage of each patient were correlated with his serum
prostatic specific antigen (PSA). Results: In this study, the mean age of the patients was 66.3
±10.54 years. Mean serum PSA was 45.48 ±32.39 ng/Ml. The mean Gleason score among the
patients studied was 7.15 ± 1.51. Gleason scores 8 and 7 were the most common among the
patients with 29.4% and 20.4% respectively, while only 2 patients (0.9%) had a Gleason score of
2.Majority of the patients (56.4%), presented with distant metastases (Stage D).The study
revealed a statistically positive correlation between the serum PSA value and the Gleason score
(Pearson’s correlation coefficient = 0.149, p= 0.031). The mean serum PSA concentrations also
tend to increase with decreasing (Gleason score based) degree of cancer differentiation (p=
0.037). So, serum PSA was positively correlated with Gleason grade. The study also revealed
atendency of the serum PSA value to increase with increasing clinical stage of the cancer (p ≤
0.05).Stage of cancer was also found to be positively correlated with the Gleason grade (Chi
square value 32.817, p value < 0.05). Conclusion:This study concluded that theserum prostatic
specific antigen (PSA) concentration has a statistically significant association with both the
Gleason grade and the clinical stage of the tumour in prostatic adenocarcinoma patients.
Therefore, patients with high prostate specific antigen are at increased risk of having a high grade
as well as an advanced stage tumour.