September 11, 2019 -- Pairing a microRNA blood test with low-dose computed tomography (CT) scans helps assess risk for lung cancer and guide screening efforts, according to an Italian study of heavy smokers presented during a presidential symposium on September 9 at the World Conference on Lung Cancer (WCLC) in Barcelona, Spain.
Volunteers in the prospective BioMILD screening study who scored at low risk for lung cancer on both tests subsequently had a low rate of lung cancer and lived longer, despite having less frequent screening, researchers reported at the meeting, which is hosted by the International Association for the Study of Lung Cancer.
The trial enrolled 4,119 people at the Fondazione IRCCS Istituto Nazionale dei Tumori cancer center in Milan. The median smoking history among the participants was 42 pack-years, and 79% were current smokers. They underwent low-dose CT and blood test screening at baseline to determine their risk for lung cancer. The participants were directed to low-dose CT screening at three-year intervals if they had negative results on both tests, signifying low risk, and more frequent screening if they had one or two positive results.
Those with two negative tests accounted for the majority of the trial population (58%), and they turned out to have a very low rate of lung cancer over time. On the other hand, lung cancer incidence was 5.96 times higher for the 37% of participants with one positive test and 36.64 times higher for the small number (5%) with two positive tests, noted lead investigator Dr. Ugo Pastorino, director of thoracic surgery at the Istituto Nazionale dei Tumori. Pastorino was also the lead researcher of the previously reported Multicentric Italian Lung Detection (MILD) trial.
The findings were statistically significant, and a similar, significant pattern was observed for lung cancer mortality, the researchers found.
The rationale for the study was that particular microRNA profiles in blood samples are associated with more aggressive cancers. The goal with heavy smokers is not to identify lung cancer but to reduce mortality, Pastorino said during a September 9 press briefing at the meeting.
Used together, the microRNA and CT tests provide information about individual risk and can help reduce the number of unnecessary repeat CT studies in screening programs, he said.
"Personalized prevention is a real option now," Pastorino said.
In a similar vein, results from the Early Detection of Cancer of the Lung Scotland (ECLS) trial were also discussed at WCLC. In that study of 12,203 participants, researchers found that the EarlyCDT-Lung blood test (Oncimmune) provided information that was complementary to CT studies and helpful for making an earlier diagnosis. Mortality data are not yet mature and the researchers are tracking outcomes.