Cancer Medicine (Dec 2019)
Association between PSA values and surveillance quality after prostate cancer surgery
Abstract
Abstract Background Although prostate‐specific antigen (PSA) testing is used for prostate cancer detection and posttreatment surveillance, thresholds in these settings differ. The screening cutoff of 4.0 ng/mL may be inappropriately used during postsurgery surveillance, where 0.2 ng/mL is typically used, creating missed opportunities for effective salvage radiation treatment. We performed a study to determine whether guideline concordance with annual postoperative PSA surveillance increases when PSA values exceed 4 ng/mL, which represents a screening threshold that is not relevant after surgery. Methods We used US Veterans Health Administration data to perform a retrospective longitudinal cohort study of men diagnosed with nonmetastatic prostate cancer from 2005 to 2008 who underwent radical prostatectomy. We used logistic regression to examine the association between postoperative PSA levels and receipt of an annual PSA test. Results 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, guideline concordance was lower for the youngest and oldest men, Black, and unmarried men. 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 = .01). Conclusions 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. Clarification of PSA thresholds for early detection vs cancer surveillance, as well as emphasizing adherence for younger and Black men, appears warranted.
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