In a study reported in JAMA Oncology,1 Nicholas A. Pickersgill, MD, of the Department of Surgery (Urology Service) at Memorial Sloan Kettering Cancer Center, New York, and colleagues found that individuals without prostate cancer undergoing annual prostate-specific antigen (PSA) testing often exhibited a PSA level below biopsy threshold in the year following an elevated test result. Sigrid V. Carlsson, MD, PhD, MPH, of the Division of Clinical Epidemiology of Early Cancer Detection, German Cancer Research Center (DKFZ), Heidelberg, Germany, is the corresponding author of this article in JAMA Oncology.
Nicholas A. Pickersgill, MD
Sigrid V. Carlsson, MD, PhD, MPH
The study involved data on men between the ages of 54 and 75 from the screening arm of the PLCO trial, who underwent annual PSA testing for 6 years between 1995 and 2006 without a prostate cancer diagnosis. The primary outcome measure was the proportion of PSA measurements above biopsy thresholds of 2.5, 3.0, and 4.0 ng/mL that decreased below the threshold at the following annual test.
Key Findings
Among 11,176 eligible patients, 2,700 were included at a biopsy threshold of 2.5 ng/mL; 1,928 were included at a biopsy threshold of 3.0 ng/mL; and 952 were included at a biopsy threshold of 4.0 ng/mL on at least one measurement. Among PSA measurements ≥ 2.5 ng/mL in 1 year, 22% (95% confidence interval [CI] = 21%–23%) decreased below 2.5 ng/mL at testing the following year. The rates were 25% (95% CI = 24%–27%) for the 3.0 ng/mL threshold and 30% (95% CI = 27%–32%) for the 4.0 ng/mL threshold.
At the patient level, 54% (95% CI = 53%–56%) of patients with at least one PSA level ≥ 2.5 ng/mL had a subsequent level below this threshold. Rates were 58% (95% CI = 56%–60%) for the 3.0 ng/mL threshold and 62% (95% CI = 59%–65%) for the 4.0 ng/mL threshold.
In a scoring system incorporating current and prior PSA levels during the study, it was found that patients with PSA levels persistently above a threshold had a less than 10% probability of PSA levels decreasing below the threshold.
The investigators concluded: “In this study, significant intraindividual variability in PSA levels was observed in this large screening cohort, with many elevated values falling below the threshold at the next yearly measurement. These findings suggest the utility of guideline recommendations to confirm elevated PSA results in most patients before performing further diagnostic evaluation and that patients with a prior PSA score above a given biopsy threshold, and no recent PSA scores below that threshold, could proceed to further diagnostic evaluation without repeat [PSA] testing.”
DISCLOSURE: The study was supported by the National Cancer Institute. Dr. Pickersgill reported no conflicts of interest. For full disclosures of the other study authors, visit jamanetwork.com.
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