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.