- Start Date: July 2024
- Funded by: National Cancer Institute (NCI)
- Principal Investigator: Nikki Carroll, MS Principal Investigator Email: Nikki.M.Carroll@kp.org
Estimating Overdiagnosis After Implementation of Lung Cancer Screening in Community-Based Healthcare Systems
GrantGrant Information
Low-dose computed tomography (LDCT) has been accepted as an efficacious population-based approach for lung cancer screening (LCS) based on findings from the National Lung Screening Trial (NLST) which demonstrated a 20% reduction in lung cancer deaths. These findings and subsequent recommendations from the US Preventative Services Task Force in December 2013 along with expanded guidelines in 2021, resulted in LCS via LDCT being implemented in a variety of community and academic settings starting in 2014. However, as with any screening program, there are concerns about the potential for LCS to lead to overdiagnosis of lung cancer. Overdiagnosis is the detection of cancers through cancer screening that never would have been diagnosed in the absence of cancer screening and would never lead to significant patient morbidity or mortality in a patient’s lifespan if left untreated. Any diagnosis of lung cancer generally causes the patient to engage in aggressive treatment and overdiagnosis may result in anxiety, serious physical harm, unnecessary losses in quality of life, and financial health-care costs. The variability, and uncertainty over the potential LCS-related harms, has led to extensive debate regarding the balance between harms and benefits of LCS. Although the strongest evidence for overdiagnosis comes from randomized control trials (RCTs) with long-term follow- up, patients participating in RCTs are generally not representative of those in community-based settings. Compared to NLST participants, individuals participating in community based LCS settings are more likely to be older, to currently smoke, and have a high comorbid burden. Specifically, participants receiving LCS care in community-based settings were more likely to have COPD, asthma, bronchiectasis, chronic bronchitis, diabetes, and hypertension compared to NLST participants, thus increasing the likelihood of death from another disease before the lung cancer progresses. These differences suggest that the magnitude of overdiagnosis may be very different from estimates derived from RCTs. Observational studies are needed to provide a source of robust evidence to inform the existence and magnitude of overdiagnosis in lung cancer for individuals receiving LCS care outside of an RCT. As LCS participation continues to evolve, this evidence is needed to inform future clinical and policy decision making. Therefore, the primary objective of this study is to produce a range of estimates of overdiagnosis among patients diagnosed with lung cancer who participated in the LCS process in community-based healthcare settings.