Assessment of ad hoc lung cancer screening at a safety net hospital

Lung cancer is the leading cause of cancer-related deaths in the United States. Low-dose computed tomography (LDCT) for lung cancer screening (LCS) can reduce lung cancer mortality among patients who meet screening criteria. We conducted a retrospective cohort study to evaluate patient characteristics and eligibility among patients referred by primary care and pulmonary providers for LDCT at a safety net hospital in San Francisco, which does not have a formal LCS program.

We extracted demographic and clinical data from individuals who had undergone LDCT between 2019 and 2023 (n=400), and from individuals referred for evaluation of suspicious pulmonary nodules between 2023 and 2024 (n=20).

Of the 400 patients who underwent LDCT, only 47.5% (n=190) had documentation supporting LCS eligibility at the time of chart review. Two lung cancers, both stage 1, were identified in those that met screening criteria; none were diagnosed among those that did not meet screening criteria. Among the 20 patients referred for pulmonary nodule evaluation, 15 met the United States Preventive Services Task Force (USPSTF) criteria for LDCT LCS, but only eight had previously undergone LCS.

The absence of a formal LCS program led to high rates of unnecessary screening for lung cancer and underutilization among those that could benefit from it. Of those that met screening criteria, the number needed to screen was 95 to detect one lung cancer, comparable to published data and highlighting the potential utility of an LCS program.