PROSTATE-SPECIFIC ANTIGEN AND AGE - IS THERE A CORRELATION - AND WHY DOES IT SEEM TO VARY

Objectives: To determine whether there is a significant correlation be tween age and prostate-specific antigen (PSA) and to explain the wide literature variations in its value. Methods: Two different groups were studied; the first (n = 403) consisted of patients undergoing prostat ectomies for symptomatic benign prostatic hypertrophy (BPH) and the se cond (n = 192) of patients with no evidence of prostate cancer who req uired no treatment. Results: The correlation coefficient found in the surgical group was low (0.09) and was statistically insignificant whil e in the second group it was much higher (0.36) and had a high statist ical significance (p < 0.001). This reflected the age difference betwe en the two groups rather than the difference in clinical characteristi cs as proved by the gradual decrease in the value of the coefficient b y the gradual exclusion of the younger age groups. The correlation bec ame statistically insignificant for those older than 60 years. Conclus ions: It is concluded that the correlation between age and PSA is a va riable one showing a gradual decline in its coefficient with the gradu al increase in the age of the population studied. This implies a relat ively orderly rise in PSA with age up to a limit of 60 years. Beyond t his age, the relationship between age and PSA becomes disorderly. This pattern of relationship can easily be explained by the known rate of growth of BPH and would explain the literature variations.