In a study reported in JAMA Oncology, Pickersgill et al 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.
Study Details
The study involved data on men aged 54 to 75 years 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 at 3.0 ng/mL; and 952 at 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 < 10% probability of PSA decreasing below the threshold.
The investigators concluded: “In this study, significant intra-individual 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.”
Sigrid V. Carlsson, MD, PhD, MPH, of the Department of Surgery (Urology Service) and the Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, is the corresponding author for the JAMA Oncology article.
Disclosure: The study was supported by the National Cancer Institute. For full disclosures of all study authors, visit jamanetwork.com.
