The potential impact of chronic obstructive pulmonary disease in lung cancer screening: implications for the screening clinic

ABSTRACT

Introduction: Following the findings of the National Lung Screening Trial (NLST), lung cancer screening is now recommended in the United States. However, post-hoc analyses of the NLST suggest that reducing lung cancer mortality through screening is highly dependent on the underlying characteristics of the screening participants, in particular, the presence of chronic obstructive pulmonary disease (COPD).

Areas covered: In this review, we outline how outcomes in lung cancer screening are significantly affected by the presence of airflow limitation, as caused by COPD, and how this might impact the assessment of eligible smokers in a lung cancer screening clinic.

Expert opinion: There is growing evidence showing that CT-based screening for lung cancer reduces lung cancer mortality. The benefits of screening exceed those seen in the NLST when screening is carried out in lower risk populations, for a longer duration, and when outcomes are compared with usual care control cohorts. In this article, we review data from a post-hoc analysis of the NLST. We suggest that whilst worsened airflow limitation is associated with greater lung cancer risk, there is also more aggressive lung cancer, reduced lung cancer operability, and for advanced COPD, reduced benefits from screening. We advocate an ’outcomes-based’ approach to screening over a ‘risk-based’ approach.

KEYWORDS:

• Lung cancer
• computed tomography
• screening
• comorbidity
• operability
• competing risk
• chronic obstructive pulmonary disease
• shared-decision making

Article Highlights

• Benefiting from lung cancer screening is dependent on a complex relationship between individual risk factors and lung cancer biology.

• Lung cancer risk does not correlate with the benefit of lung cancer screening in a simple linear relationship.

• Risk of lung cancer correlates closely with the presence of chronic obstructive pulmonary disease (COPD).

• In a post-hoc analysis of NLST data, we found the presence of COPD is associated with more aggressive lung cancer, lower operability and shorter life expectancy, which collectively may undermine the benefits of screening.

• We found subgroups of eligible smokers who do better with screening and these include women, those with no airflow limitation and those with undiagnosed COPD.

• An ‘outcomes-based’ approach to screening recognizes subgroups of eligible smokers who are most likely to benefit from screening as well as those for whom the benefits may be marginal.

• Eligible smokers who are at intermediate risk of lung cancer appear to gain the most from lung cancer screening through the combination of elevated risk, lower comorbid disease, and greater life expectancy.

• In the future, biomarkers may help identify eligible smokers who get the most from CT screening by combining personal clinical characteristics with bio-data that reflect lung cancer biology.

• We suggest shared-decision making should include the assessment of eligibility, lung cancer risk and the likely benefit achieved from screening.

Declaration of interest

RJH has no significant conflicts of interest with respect to the subject matter discussed in this correspondence. RPY is a founder, shareholder, and advisor to Synergenz BioScience Limited who hold patents for gene-based risk assessment in lung cancer.

Reviewers Disclosure

A reviewer on this manuscript has disclosed being a part-time employee and shareholder of VisionGate, Inc. Peer reviewers on this manuscript have no other relevant financial relationships or otherwise to disclose.

Additional information

Funding

Findings reported in this article derive from a post-hoc analysis of data from the National Lung Screening Trial (NLST) generously funded in part through an academic grant from Johnson and Johnson (USA).