MicroRNA blood test enhances results of low-dose CT screening for lung cancer
BARCELONA — A microRNA blood test used in combination with low-dose CT screening reduced unnecessary repeat imaging and demonstrated value as a tool to assess individual lung cancer risk, according to results of the bioMILD trial presented during the presidential symposium of International Association for the Study of Lung Cancer World Conference on Lung Cancer.
“We know that CT screening can reduce mortality; the question is how to use it best in high-risk individuals,” Ugo Pastorino, MD, of the Istituto Nazionale dei Tumori Foundation, said during a press conference. “The bioMILD trial evaluated the utility of combined blood microRNA testing and low-dose CT screening to predict individual lung cancer risk. For a group of individuals of the same age and the same [smoking] exposure, can we find those who are going to develop lung cancer?”
Researchers also sought to assess the feasibility of longer screening intervals for those with double-negative baseline CT screens and microRNA, and to reveal the potential damage of postponing CT after 2 or 3 years in terms of stage I detection, resection rates and interval cancers.
The analysis included 4,119 individuals aged 50 to 75 years who had more than 30 pack-years of smoking history and who had stopped smoking 10 or fewer years prior.
Researchers classified participants into three groups according to their testing results: double negative, meaning they had a low-risk microRNA blood test result and a negative CT finding (58%); single positive, meaning they had a positive lesion on CT imaging or an intermediate- or high-risk microRNA blood test result (37%); or double positive, meaning both CT imaging and the blood test were positive (5%).
A lesion of at least 113 mm3 on CT defined a positive result, which Pastorino noted was a “pretty high” threshold.
“Usually the threshold cutoff is much lower but, in fact, the newly published Lung-RADS criteria use exactly the same cutoff,” he said.
Lung cancer incidence at 4 years appeared significantly higher among patients with single-positive results (HR = 5.96; 95% CI, 3.38-10.52) or double-positive results (HR = 36.64; 95% CI, 20.31-66.11) compared with the double-negative group.
“The lung cancer incidence is enormously different among these groups that have the same composition of age, sex and tobacco consumption,” Pastorino said.
Risk for mortality at 4 years followed the same pattern, with much higher risks observed for the single-positive (HR = 4.67; 95% CI, 1.26-17.24) and double-positive (HR = 32.34; 95% CI, 8.55-121.6) groups than the double-negative group.
“Of interest, incidence and mortality of the double-negative group at 4 years is very low, almost flat,” Pastorino said.
Overall, these results suggest that blood microRNA and low-dose CT screening together can improve the optimal screening intensity and reduce unnecessary low-dose CT repeat imaging, he added.
“What is even more important is that the knowledge of individual biologic risk by microRNA and low-dose CT improves the efficacy of screening and should guide future preventive strategies,” he said. “The problem in a heavy smoker is not just detecting lung cancer, it’s reducing their mortality. Personalized prevention is a real option now; that means diagnosis, but also preventive measures with smoking cessation and chemoprevention, etc.” – by Alexandra Todak
Pastorino U, et al. Abstract PL02.04. Presented at: International Association for the Study of Lung Cancer World Conference on Lung Cancer; Sept. 7-10, 2019; Barcelona.
Disclosures: Pastorino reports no relevant financial disclosures. Please see the abstract for all other authors’ relevant financial disclosures.