microRNA plus LDCT guides optimal lung cancer screening intensity
medwireNews: Combining low-dose computed tomography (LDCT) with a blood microRNA test can help establish the most appropriate screening frequency among heavy smokers at risk for lung cancer, study data show.
Ugo Pastorino, from Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy, told delegates at the IASLC World Conference on Lung Cancer 2019 in Barcelona, Spain, that targeting LDCT intervals based on this approach did not detrimentally affect lung cancer detection or mortality.
Pastorino explained that the National Lung Screening Trial previously demonstrated that lung cancer screening with three annual rounds of LDCT reduced lung cancer mortality, while the MILD trial showed that extending the intervention beyond 5 years enhanced the benefit of screening.
The current bioMILD trial evaluated whether adding a blood microRNA test to the screening program can reduce unnecessary LDCT repeats.
The study included 4119 volunteers aged 50–75 years (median 60 years, 39% women) who had at least 30 pack–years of smoking (median 42 pack–years). Of these, 79% were current smokers and 21% had stopped smoking within the previous 10 years.
At baseline, all participants underwent LDCT and blood microRNA screening. Individuals with negative findings on both tests (58%) were assigned to repeat LDCT after 3 years, while those with either positive microRNA or indeterminate/positive LDCT (37%) and those with both positive microRNA and indeterminate/positive LDCT (5%) were rescreened by LDCT within 1 year.
After four rounds of screening 115 lung cancers were diagnosed, giving a cumulative incidence of 2.8%.
Pastorino reported that cumulative lung cancer incidence differed significantly among the three groups, at 0.6% for people with a double negative result on initial screening, 3.8% for those with a single positive result, and 20.1% for those with a double positive screening result at baseline.
There were also significant between-group differences in the incidence of lung cancer mortality, at 0.1%, 0.6%, and 3.8%, with two negative, one positive, and two positive results, respectively.
Further analysis showed that individuals with one positive screening result were six times more likely to develop lung cancer and 4.7 times more likely to die from lung cancer than those with a negative microRNA and LDCT result, while people with two positive results were 36.6 and 32.2 times more likely, respectively.
By contrast, there were no significant differences among the three groups in interval cancer incidence, the proportion of stage I lung cancers detected, and the number of lung cancers resected.
Pastorino concluded: “Knowledge of individual biologic risk by microRNA and LDCT improves the efficacy of screening and should guide future preventive strategies.”
By Laura Cowen
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