In a Finnish study reported in JAMA Oncology, Vettenranta et al found that statin use did not appear to markedly affect the benefits of prostate-specific antigen (PSA) screening for prostate cancer.

As stated by the investigators, “PSA screening for prostate cancer has resulted in a slight reduction in prostate cancer mortality but also a concomitant overdiagnosis of low-risk tumors. PSA levels [can be lowered] by use of cholesterol-lowering statin drugs, but the association of statin use with PSA screening performance is unknown.”

Study Details

The study was a post hoc subgroup analysis of a cohort from the population-based Finnish Randomized Study of Prostate Cancer Screening. Men aged 55 to 67 years were randomly assigned to receive three invitations for PSA screenings at 4-year intervals from 1996 to 2007 or to routine care. Follow-up was through December 2015. Information on statin purchases from 1996 to 2009 was obtained from a national prescription registry. 

Key Findings

The analysis included 78,606 men with available statin purchase data. Among these, 12,059 (38%) in the screening group and 19,567 (41%) in the control group were statin ever-users.

PSA screening was associated with increased diagnosis of prostate cancer among statin nonusers, with rates of 11.2 vs 8.6 per 1,000 person-years in the screening vs control group (rate ratio [RR] = 1.31, 95% confidence interval [CI] = 1.24­–1.38). Among statin users, no significant increase in incidence was observed between the screening and control groups (6.9 vs 5.9/1,000 person-years, RR = 1.02, 95% CI = 0.95–1.10; P < .001 for interaction).

The screening group had increased risk of Gleason ≤ 6 tumors compared with the control group, regardless of statin use, but the difference was smaller among statin users; rate ratios were 1.70 (95% CI = 1.58–1.82) among nonusers and 1.29 (95% CI = 1.15–1.44) among ever-users.

The screening group had an increased risk of localized tumors among nonusers but not among ever-users: risk ratios were 1.37 (95% CI = 1.30–1.45) among nonusers and 1.04 (95% CI = 0.96–1.13) among ever-users.

Statin use did not modify the association of screening with Gleason 8 to 10 tumors, with rate ratios of 0.91 (95% CI = 0.82–1.04) among nonusers and 0.85 (95% CI = 0.72–1.02) among ever-users. Findings were similar for advanced tumors, with rate ratios of 0.83 (95% CI = 0.70–0.99) among nonusers and 0.85 (95% CI = 0.66–1.11) among ever-users.

Screening was associated with lower incidence of metastatic tumors, irrespective of statin use. Metastatic tumors accounted for 6% of all cases among ever-users and 8% among nonusers in the screening group vs 9% and 13%, respectively, in the control group.

The investigators concluded, “In this post hoc subgroup analysis of a cohort from a population-based randomized clinical trial, PSA screening among statin users was associated with a decreased incidence of advanced prostate cancer that was similar among statin nonusers, but with less increase in detection of low-grade localized tumors in statin users than in nonusers. These findings suggest that statin use does not materially compromise benefits of PSA-based screening.”

Arla Vettenranta, MD, of Tampere University, is the corresponding author for the JAMA Oncology article.

Disclosure: The study was funded by the Competitive State Research Financing of the Expert Responsibility area of Tampere University Hospital, Finnish Cancer Society, and Academy of Finland. For full disclosures of the study authors, visit jamanetwork.com.