ANN ARBOR, MI—Does guideline concordance with annual postoperative prostate-specific antigen surveillance increase when PSA values exceed 4 ng/mL, even though that represents a screening threshold that is not relevant after surgery?

That was the question raised in an article in Cancer Medicine. A study team led by VA Ann Arbor, MI, Healthcare System and University of Michigan researchers pointed out that, although prostate-specific antigen testing is used for prostate cancer detection and posttreatment surveillance, thresholds in those settings differ.1

“The screening cutoff of 4.0 ng/mL may be inappropriately used during post-surgery surveillance, where 0.2 ng/mL is typically used, creating missed opportunities for effective salvage radiation treatment,” they explained.

The study used VHA data to perform a retrospective longitudinal cohort study of men diagnosed with nonmetastatic prostate cancer from 2005 to 2008 who underwent radical prostatectomy.

Results indicated that, among 10,400 men and 38,901 person-years of follow-up, annual guideline concordance decreased from 95% in Year 1 to 79% in Year 7. After adjustment, researchers determined that guideline concordance was lower for the youngest and oldest men, as well as men who were black and unmarried.

The study documented that guideline concordance significantly increased as PSA exceeded 4 ng/mL (adjusted odds ratio 2.20 PSA > 4-6 ng/mL vs. PSA > 1-4 ng/mL, 95% confidence interval 1.20-4.03; P=0.01).

“Guideline concordance with prostate cancer surveillance increased when PSA values exceeded 4 ng/mL, suggesting a screening threshold not relevant after prostate cancer surgery, where 0.2 ng/mL is considered treatment failure, is impacting cancer surveillance quality,” the authors concluded. “Clarification of PSA thresholds for early detection vs. cancer surveillance, as well as emphasizing adherence for younger and black men, appears warranted.”

1.    Chapman CH, Caram MEV, Radhakrishnan A, Tsodikov A, et. Al. Association between PSA values and surveillance quality afterprostate cancer surgery. Cancer Med. 2019 Nov 5. doi: 10.1002/cam4.2663. [Epubahead of print] PubMed PMID: 31691526.