The combination of a novel autoantibody diagnostic test for the early detection of lung cancer followed by a chest computed tomography (CT) scan of high-risk individuals can decrease late-stage lung cancer diagnoses, according to a study presented during the Presidential Symposium of the 2019 World Conference on Lung Cancer, held September 7-10 in Barcelona, Spain.
Frank M. Sullivan, MD, professor of primary care medicine at the University of St. Andrews’ Sir James Mackenzie Institute for Early Diagnosis Population and Behavioural Science Division in Scotland presented the much anticipated findings of a 12,209 participant randomized clinical trial.
Dr. Sullivan stated that 41% of participants in the patient cohort who received the combined tests were diagnosed within 24 months with stage 1 or 2 lung cancer, compared with 27% of the control arm of the study, who were monitored with normal clinical practice. The autoantibody diagnostic test identified 41% of lung cancers with a specificity of 90%. Chest CT identified 67% of lung cancers with a specificity of 49%. During the study period, 127 lung cancers were diagnosed.
The Detection in Blood of Autoantibodies to Tumour Antigens as a Case-finding Method in Lung Cancer Using the Early CDT-Lung Test (ECLS) randomized, parallel assignment clinical trial was launched in August 2013 to evaluate the effectiveness of an autoantibody diagnostic test combined with diagnostic imaging in detecting lung cancer at earlier stages, as compared with standard clinical monitoring of high-risk individuals in Scotland. Dr. Sullivan and colleagues wanted to determine if lung cancer could be detected early in high-risk patients, potentially and potentially reduce mortality outcomes associated with stage III and IV lung cancer.
The study recruited patients affiliated with general practices in economically deprived communities of Scotland who were 50 to 75 years old, and who had at least a 2% risk of developing lung cancer within two years. Participants included current or former cigarette smokers with at least a 20 pack-year history, or with a less significant history of smoking but a family history of lung cancer. Participants also had to be healthy enough to undergo pulmonary resection or have stereotactic radiotherapy treatments if diagnosed with the disease.
All participants underwent a clinical visit that included a blood draw. Blood of participants in the interventional arm was tested with an EarlyCDT®-Lung Test (Oncimmune, Nottingham, UK), which measures blood levels of seven autoantibodies to tumor-associated antigens that are linked to lung cancer. Individuals with positive test results had a chest radiograph and/or a noncontrast thoracic CT scan. A contrast-enhanced CT scan was subsequently performed if a suspicious opacity was identified. If the initial CT scan(s) revealed no evidence of lung cancer, subsequent chest CT scans were performed every six months for the next two years.
Dr. Sullivan, the study’s principal investigator, reported that 9.8% of the intervention group had a positive autoantibody diagnostic test, and that 18 patients (3.4% of this subgroup) developed lung cancer within 24 months. A total of 56 cases of lung cancer were diagnosed in the interventional arm and 71 cases in the control arm. “However, only 33 patients in the interventional group were diagnosed with late-stage lung cancer, compared to 52 patients in the control group,” said Dr. Sullivan.
“The study was not powered to detect a difference in mortality after two years; however, there was a non-significant trend suggesting fewer deaths in the intervention arm compared to the control (87 versus 108 respectively),” he said. “Similar results were noted relating to lung cancer-specific mortality (17 versus 24).”
Lung cancer development and mortality outcomes for all study participants will be monitored using Scottish Information Services Division data for an additional five years.
Dr. Sullivan has high hopes for an autoantibody diagnostic test allowing stratification of individuals according to their risk of developing lung cancer. “This could permit a targeted approach to CT scanning for early lung cancer detection, which may be a more cost-effective and potentially less harmful approach to population screening,” he said.
WCLC 2019: Autoantibody test plus + chest CT may reduce lung cancer mortality. Appl Radiol.