B14-06 A Cluster Randomized Interventional Study of a Blood-Based Lung Cancer Screening Test in Primary Care Practices; The FIRSTLUNG Study, NCT06145750

Rationale

Lung cancer screening (LCS) remains underutilized in the United States, such that in 2022, only 18% of patients who were eligible received a Low Dose CT (LDCT) scan for LCS. We postulated that if a peripheral blood test which was highly sensitive for lung cancer were available, and more convenient for patients than a CT scan, it might augment the rate of LCS. With this aim, DELFI Diagnostics developed a blood-based genomic lung cancer screening test (pWGFrag-Lung, FirstLook) that could be obtained as a routine annual blood draw in a primary care setting. Here we present results of a cluster randomized trial to determine whether the availability of the blood test increased lung screening rates.

Methods

Primary care practices across multiple US health systems were block randomized 1:1 to Group A (usual care) or Group B (usual care plus access to the blood test). Patients eligible for analysis met 2021 USPSTF criteria for lung cancer screening and had never completed LCS or were past due for their annual screening. Outcomes were compared using time-to-event analyses. Multi-variable analyses adjusted for patient (age, sex, race/ethnicity, pack-year smoking history, current smoking status) and medical practice (network, rural/urban status) characteristics. Patients were followed up to 11 months. The primary outcome was completion of “any lung cancer screening” (LDCT or blood test); secondary outcome was completion of LDCT.

Results

28 primary care practices were randomized: 15 practices to usual care (Group A; 1662 eligible patients), and 13 practices to usual care plus access to the blood test (Group B; 1291 eligible patients). Primary outcome: Any lung cancer screening (LDCT or blood test) occurred more frequently in Group B practices (20.9%) than Group A practices (8.4%): multi-variable HR = 2.73 (95% CI: 1.91, 3.89; p = <0.001). Secondary outcome: LDCT screening was more common in Group B (13.4%) than Group A (8.4%): multi-variable HR: 1.47 (95% CI: 1.14, 1.89; p = <0.01).

Conclusions

Access to a lung screening blood test within primary care practices appeared to significantly increase completion rates of any form of lung cancer screening and completion of LDCT screening when compared to practices that did not have access to the blood test. Given the low rates of lung cancer screening via LDCT, access to a lung cancer screening blood test such as the pWGFrag-Lung could substantially increase LCS rates and reduce lung cancer mortality.

This abstract is funded by: Delfi Diagnostics Inc.