The use of age-specific reference ranges for serum prostate specific antigen in men 60 years old or older

Several investigations have determined that the serum prostate specific antigen (PSA) concentration is dependent upon patient age and, as a result, reference ranges wider than 0.0 to 4.0 ng./ml. have been suggested for men 60 years old or older. To determine the clinical usefulness of the age-specific reference ranges--0.0 to 4.5 ng./ml. for men 60 to 69 years old and 0.0 to 6.5 ng./ml. for men 70 years old or older--the medical records of 2,988 men 60 years old or older who presented to a single urological practice were examined. All patients were evaluated with a serum PSA determination, digital rectal examination and transrectal ultrasound. A total of 1,686 prostate biopsies was performed (biopsy rate 56%) and 608 cancers were diagnosed (cancer detection rate 20%). By using the age-specific reference ranges as compared to the 0.0 to 4.0 ng./ml. reference range, the sensitivity of PSA for detecting early prostate cancer decreased by 9%, while the specificity and positive predictive value increased by 11% and 5%, respectively. If the age-specific reference ranges had been used 92 prostate biopsies (5.5%) performed could have been avoided, while 19 men in the study population (0.6%) would not have had prostate cancer diagnosed. Of the nondetected cancers 13 (67%) occurred in men 70 years old or older and 18 (95%) were small tumors of favorable pathological status unlikely to be of clinical consequence in these older men. These preliminary findings support the clinical usefulness of the wider age-specific reference ranges in men 60 years old or older. A prospective randomized clinical trial is currently underway to confirm the appropriateness of age-specific reference ranges compared to the reference range of 0.0 to 4.0 ng./ml.