Prostate-specific antigen and digital rectal examination in long-term follow-up of stage A1 prostatic carcinoma.
Twenty-six individuals with Stage A1 carcinoma of the prostate (less than or equal to 5%, Gleason score less than or equal to 4) diagnosed from 1969 to 1980 were evaluated with digital rectal examination (DRE) and prostate-specific antigen (PSA). This unique cohort, sixty-one to eight-two years of age (median 72 years), had a mean interval from diagnosis of thirteen years (median 12.5 years). Abnormal findings on DRE were found in 6 individuals, whereas only one elevated PSA was detected. Ninety-six percent of the PSA levels were less than 3.0 ng/mL and nearly 60 percent of the group had 1.0 ng/mL or less. These levels compare favorably with healthy control subjects under forty years of age and with the limited data available for PSA in healthy men over seventy years of age (87% and 26%, respectively). While biopsy showed persistent or recurrent carcinoma in 2 of 5 individuals, further evaluation disclosed only localized disease. Though the PSA provided little additional information to DRE in the individual patient, it appears from an overview of this group that a low level of PSA in Stage A1 prostatic carcinoma may be associated with long-term survival.