PSA Screening History and Severity of Prostate Cancer at Diagnosis

Chicago—In 2012, the US Preventive Services Task Force gave the use of prostate-specific antigen (PSA) screening to detect prostate cancer a Grade D recommendation. Studies conducted recently in the United States have demonstrated associations between declines in PSA screening and concomitant increases in advanced prostate cancer at diagnosis. A retrospective study conducted by Jennifer Cullen, MPH, PhD, was designed to examine the association between screening for PSA and aggressiveness of prostate cancer. Study results were reported during a poster session at the 2017 ASCO Annual Meeting. The poster was titled History of PSA Screening on Prostate Cancer Aggressiveness.

The study cohort was a racially diverse, military cohort with equal access to health care. The study assessed prostate cancer patients undergoing radical prostatectomy from 1994 to 2015 at Walter Reed National Military Medical Center in Bethesda, MD. The researchers classified whole-mounted prostatectomy specimens using the 2014 International Society of Urological Pathology Gleason grading system.

Excluding the diagnostic PSA, screening history was categorized as: six or more six PSAs prior to prostate cancer diagnosis (uppermost quartile); or one to five PSAs (lower quartiles) versus no screening history. National Comprehensive Cancer Network (NCCN) risk stratum and Gleason upgrade from biopsy to radical prostatectomy were examined using multivariable logistic regression. Multivariable Cox proportional hazards were used to model time to biochemical recurrence. The multivariable models accounted for age at radical prostatectomy, race, family history, and obesity (body mass index >30 vs ≤30 kg/m2). The Gleason upgrade and biochemical recurrence models also accounted for NCCN risk classification.

Among the 1772 eligible patients, median follow-up was 7.0 years and median age at radical prostatectomy was 59.8 years. Prior to diagnosis of prostate cancer, 42% of the men had one to five PSA screenings and 19% had more than six PSA screenings. Multivariable logistic regression showed greater odds of intermediate- or high- versus low-risk disease for men with PSA screening history of none versus one to five screenings (odds ratio [OR], 1.33; 95% confidence interval [CI], 1.03-1.70; P=.028) but not for none versus six or more prior screenings (P=.44); as well as increased odds of Gleason upgrade for none versus six or more (OR, 1.81; 95% CI, 1.23-2.7; P<.001).

Multivariate Cox proportional hazards models indicated incrementally poorer biochemical recurrence-free survival as screening history decreased (hazard ratio [HR]none vs ≥6=2.27; 95% CI, 1.54-3.33; P<.001); HRnone vs 1-5=1.49; 95% CI, 1.15-1.92; P=.002).

In conclusion, the researchers said, “In this radical prostatectomy cohort, higher risk stratum, increased Gleason upgrade, and poorer biochemical recurrence-free survival were associated with no PSA screening history. Biochemical recurrence-free survival was incrementally worsened by less PSA screening. A complete absence of PSA screening may lead to more aggressive disease at presentation and poorer clinical outcomes.”

Source: Cullen J, Gerald T, Burke A, et al. History of PSA screening on prostate cancer aggressiveness. Abstract of a poster presented during the 2017 American Society of Clinical Oncology Annual Meeting, June 5, 2017, Chicago, Illinois.