BARCELONA – Adding a blood microRNA (miRNA) assay to low-dose computed tomography (LDCT)–based lung cancer screening in heavy smokers bolsters lung cancer prevention efforts, according to findings from the prospective bioMILD trial.
Dr. Ugo Pastorino
Specifically, the addition of the miRNA assay appears to reduce unnecessary repeat LDCT scans based on individual risk profiles without adversely affecting lung cancer detection or mortality, Ugo Pastorino, MD, director of thoracic surgery at the Istituto Nazionale dei Tumori Foundation, Milan, reported at the World Conference on Lung Cancer.
Of 4,119 volunteers with a median age of 60 years and a median of 42 pack-years who were enrolled between January 2013 and March 2016, 2,384 (58%) were assigned a 3-year LDCT repeat according to their double-negative baseline LDCT and miRNA profile, whereas 1,526 (37%) with a single-positive screen (either a positive miRNA or indeterminate/positive LDCT) and 209 (5%) with double positive (both a positive miRNA and indeterminate/positive LDCT) were assigned to annual or shorter LDCT repeat.
After four screening runs, a total of 115 lung cancers were diagnosed. The cumulative lung cancer rates “were enormously different” in the 3 groups, despite similar group composition with respect to age, gender, and tobacco consumption (0.6% for double-negative screening, 3.8% for single-positive screening, and 20.1% for double-positive screening), and lung cancer mortality was 0.1%, 0.6%, and 3.8% in the groups, respectively, Dr. Pastorino said at the conference, which is sponsored by the International Association for the Study of Lung Cancer.
However, no significant differences were seen in the proportion of stage I lung cancers, resection rates, or interval cancer incidence in subjects sent to 3-year LDCT repeat, he noted.
The bioMILD trial was designed in the wake of the National Lung Screening Trial (NLST), which showed that three annual LDCT rounds for lung cancer screening reduced lung cancer mortality, and the Multicentric Italian Lung Detection (MILD) trial, which provided additional evidence that intervention beyond 5 years with annual or biennial rounds enhanced the benefit of screening.
Dr. Pastorino, the lead author on the MILD trial, previously reported that miRNA expression profiles in tumors and in normal lung tissue indicate aggressive lung cancer development and that specific miRNA signatures can be identified in plasma samples up to 2 years before spiral-CT detection of the disease.
The bioMILD trial tested the additional value of an miRNA assay at the time of LDCT.
Subjects were current (79%) or former heavy smokers, and 39% were women.
The findings suggest that adding the miRNA assay to LDCT for lung cancer screening is a “valuable and safe tool to assess individual risk profile and reduce unnecessary LDCT repeats in lung cancer screening,” Dr. Pastorino said.
“But what is more important for us [is that] the knowledge of individual biologic risk can improve the efficacy of screening, but can [also] guide prevention strategies because the problem in a heavy smoker is not to just detect lung cancer, it’s to reduce mortality,” he said at a press conference highlighting the findings. “And so, personalized prevention is a real option now, and that means diagnosis, but also preventive measures [such as] smoking cessation and chemoprevention.”
Invited discussant Harry J. de Koning, MD, PhD, professor of public health and screening evaluation at Erasmus Medical Center, Rotterdam, the Netherlands, noted that no other studies have evaluated screening intervals longer than 2 years, but he agreed that “reducing regular follow-up scans based on additional risk information is a way forward.”
However, the approach would increase costs, he said, adding that large, prospective, randomized, controlled trials are needed to confirm the safety of such approaches in nationwide programs.
Dr. Pastorino and Dr. de Koning each reported having no disclosures.
SOURCE: Pastorino U et al. WCLC 2019, Abstract PL02.04