COPD tied to earlier lung cancer diagnosis

Chronic obstructive pulmonary disease (COPD) is associated with an earlier diagnosis of lung cancer, according to a cross-sectional, real-world study.

“People with COPD have a higher risk of lung cancer and worse outcomes compared with people without COPD,” said the researchers. “[However,] COPD is often undiagnosed, and people may not seek healthcare because of stigma related to smoking. This could delay lung cancer diagnosis.”

To determine whether lung cancer is more likely to be diagnosed in the early or advanced stages in individuals with COPD, the researchers conducted a population-based study using the Ontario Cancer Registry database. Participants were individuals who have been diagnosed with lung cancer between April 2008 and January 2020 (n=86,730; 55 percent with COPD). Of these, about three-quarters (72 percent) were diagnosed in the advanced stages (stage III/IV). [ATS 2022, abstract P162]

When stratifying by COPD status, compared with those who had no co-existing COPD, the odds of diagnosing lung cancer in the advanced stages on weighted multivariable analysis were lower for participants with COPD (odds ratio [OR], 0.70, 95 percent confidence interval [CI], 0.68–0.72), previously undiagnosed COPD (OR, 0.68, 95 percent CI, 0.66–0.70), and undiagnosed COPD (OR, 0.77, 95 percent CI, 0.73–0.82).

Between individuals with undiagnosed and previously diagnosed COPD, the likelihood of receiving a diagnosis of lung cancer in the advanced stages was greater among participants in the former versus the latter group (OR, 1.18, 95 percent CI, 1.12–1.24).

“[Nonetheless, these data imply that] regardless of whether it was previously diagnosed or undiagnosed, COPD was associated with early-stage [lung cancer] diagnosis,” said the researchers. The early-stage diagnosis may have been driven by factors such as living in a rural or high-income urban area in Ontario, Canada, higher healthcare utilization, or seeking treatment with a specialist. “Lung cancer could be detected earlier in those with COPD because of symptom overlap, established healthcare access, and routine assessments,” the researchers explained further.

After adjusting for sociodemographic factors and prior healthcare utilization, other factors associated with early-stage lung cancer diagnosis were asthma, another cancer (non-lung) in the previous 5 years, and certain types of non-small-cell lung cancer (NSCLC). For advanced-stage lung cancer diagnosis, the primary factors were male sex, previous pneumonia, diabetes, and SCLC.

Early detection important

Both lung cancer and COPD remain closely linked as they share several common pathways for activation. Screening COPD patients for cancer development could enable early detection and potentially improve treatment outcomes. [Lung Cancer 2015;90:121-127]

“Earlier diagnosis of COPD itself is critical to prevent delays in lung cancer detection among this high-risk population … Lung cancer diagnostics would benefit from enhanced partnerships with COPD healthcare providers,” said the researchers.