Nonadherence to protocol screenings in a screening trial for multiple cancers was associated with higher overall mortality, excluding deaths from cancers observed in the trial, according to a secondary analysis published in JAMA Internal Medicine.
A pair of investigators from the National Cancer Institute in Maryland conducted a secondary analysis to determine the link between nonadherence to cancer screening tests and death in the Prostate, Lung, Colorectal and Ovarian Cancer Screening trial (PLCO; ClinicalTrials.gov Identifier, NCT00002540), not including death from the cancers studied in the trial.
Of the 77,443 intervention arm participants who underwent chest radiography and flexible sigmoidoscopy, prostate-specific antigen tests and digital rectal examinations (men only), and cancer antigen 125 test and transvaginal ultrasonography (women only), 64,567 (29,537 women; 35,030 men; average age, 62.3 years) were included in the secondary study. Nearly 85% of participants (n=55,065) were adherent, 3.9% (n=2548) were partially adherent, and 10.8% were nonadherent (n=6954) with baseline screening protocol.
The hazard ratio for mortality, excluding cancers in the study, within 10 years of follow-up was 1.73 for nonadherent participants compared with fully adherent participants, and 1.36 for partially adherent participants compared with fully adherent participants. The hazard ratio for nonadherent participants compared with fully adherent participants dropped to 1.46 after medical risk factor and behavioral-related factor mortality adjustments.
“Although the present study had several limitations, to our knowledge, it is among the first to investigate the association between adherence to cancer screening and mortality from unrelated causes,” the authors wrote.
“Future studies should investigate this association in clinical care settings outside of a research trial context,” concluded the investigators.
Pierre-Victor D, Pinksy PF. Association of nonadherence to cancer screening examinations with mortality from unrelated causes: a secondary analysis of the PLCO cancer screening trial [published online December 28, 2018]. JAMA Intern Med. doi:10.1001/jamainternmed.2018.5982