ATLANTAIn patients with T1c prostate cancer undergoing radical prostatectomy, a PSA level of 2.6 to 4.0 ng/mL may be associated with more favorable pathology than a score of 4.1 to 6.0 ng/mL, according to a study presented at the 101st Annual Meeting of the American Urological Association (abstract 474).
Since the PSA test was introduced, controversy has surrounded the proper use of cut-points for recommending biopsy in men with normal digital rectal exams. "A traditional cut-point of 4.0 was set during the early use of the test; however, now we know that there is no PSA level at which we can guarantee the absence of prostate cancer," said study author Danil V. Makarov, MD.
Lowering the cut-point carries the risk of increasing the likelihood of diagnosing clinically insignificant cancers. Dr. Makarov and colleagues at John Hopkins undertook a study to determine the clinical benefit of treating men with "low" vs "slightly elevated" PSA levels.
The investigators evaluated outcomes in 2,896 men with PSA levels of 2.5 to 4.0 ng/mL (n = 784) vs 4.1 to 6.0 ng/mL (n = 2,112) who were treated with radical prostatectomy between 1985 and 2004 for stage T1c prostate cancer. A total of 1,534 men had follow-up data available.
At 10 years after surgery, there was a nonsignificant trend toward greater PSA-free survival among men with a lower baseline PSA. Analysis of Kaplan-Meier survival estimates showed non-overlapping 95% confidence intervals at 10 years, suggesting a possible benefit for treating patients at a lower PSA.
In the study, men with lower PSA values tended to be younger and tended to be diagnosed more recently than men with higher PSA values. They were significantly less likely to have a Gleason score of 7 or higher (P = .004) positive surgical margins (P = .002) or extra-prostatic extension (P = .001). PSA level did not correlate with seminal vesicle invasion or lymph node metastases.
Dr. Makarov posed the question"Do the potential modest benefits from a lowered PSA cut-point justify the problems caused by lowering the cut-pointie, more biopsies, greater costs, detection of more insignificant cancers and treatment?" Future studies are needed to address this important question, he said.