A randomised controlled trial of the detection in blood of autoantibodies to tumour antigens as a case-finding method in lung cancer using the EarlyCDT-Lung test in Scotland (ECLS).

Conference: 
SAPC ASM 2015 - Oxford - Evidence and innovation in primary care
Talk Code: 
EP3D.7

The problem

Since the majority of lung cancer cases are detected at a late stage the prognosis is poor leading to a nihilistic approach in many cases. In the USA the National Lung Screening Trial (NLST) reported 20% reductions in lung cancer mortality in 2011. As a primary screening modality CT is expensive and leads to significant morbidity in individuals whose tests are false positives however. The EarlyCDT-lung test detects autoantibodies to proteins in the earliest stages of the disease with a specificity of 93%. Our research question is: does using the EarlyCDT-Lung test reduce the incidence of patients with late-stage lung cancer (3 & 4) or unclassified presentation (U) at diagnosis, compared with standard practice?

The approach

An RCT of 10-12 000 participants in areas of Scotland within the lowest quintile of deprivation. Adults aged 50 to 75 who are at 1.2% risk over the next 2 years are eligible to participate. They should be healthy enough to undergo curative interventions. We are undertaking a randomised comparison of the EarlyCDT-lung test and follow-up imaging with standard clinical practice. The primary outcome is the difference, after 24 months, between the rates of patients with stage 3, 4 or unclassified lung cancer at diagnosis. Participants who develop lung cancer will be followed-up via electronic record-linkage to the Scottish Cancer Registry and other Scottish Morbidity Register databases to assess both time to diagnosis and stage of disease at diagnosis in the long-term.The secondary outcomes are cost-effectiveness, and a range of psychological measurements. There is a nested qualitative study of the psychological effects test of results on participants.

Findings

In the first 13 months of recruitment 8 172 patients have been recruited and 9.5% of those tested have had a positive blood test with six early cancers and 12 abnormalities undergoing further investigation detected to date in the intervention arm. The current estimated sensitivity of the test is 67% with a specificity of 91% and a Positive Predictive Value of 1.8 and a Negative Predictive Value of 99.9.

Consequences

: The study will determine the EarlyCDT-Lung test’s clinical and cost effectiveness. It will also assess potential morbidity arising from the test and potential harms and benefits of a negative EarlyCDT-Lung test result.

Credits

  • Frank Sullivan, University of Dundee, Dundee, UK
  • Stuart Schembri, University of Glasgow, Glasgow, UK
  • Frances Mair, University of Aberdeen, Aberdeen, UK
  • Colin McCowan, University of Aberdeen, Aberdeen, UK
  • Lewis Ritchie, University of Nottingham, Nottingham, UK
  • Denise Kendrick