Chest X-rays Linked to Earlier Lung Cancer Detection and Improved Outcomes

New research shows that clinician groups in England that request more chest X-rays for patients with symptoms such as persistent cough are more likely to detect lung cancer at earlier, more treatable stages. Published in March in the British Journal of General Practice, the paper highlights the potential of this simple, cost-effective tool in early detection of lung cancer.

Stephen Bradley, Ph.D.

The study was led by Stephen Bradley, Ph.D., senior lecturer and researcher at the University of Sheffield School of Medicine and Population Health. The aim was to determine whether higher rates of chest X-ray referrals in general practice were associated with earlier detection and better outcomes for lung cancer patients.

To find out, the researchers analyzed records from more than 190,000 lung cancer patients in England between 2014 and 2018. This observational study linked cancer registry data to chest X-ray rates across 7,400 general practices in England.

The study found that practices with the highest rates of chest X-ray referrals were more likely to detect lung cancer at earlier, more treatable stages. Specifically, patients in these practices were less likely to be diagnosed at stage III or IV, with a significant reduction in late-stage diagnoses

Furthermore, patients attending practices with higher chest X-ray rates also experienced improved survival rates. The hazard ratio for death within one year was 0.92, and for five-year survival, it was 0.95. After adjusting for factors like smoking history, COPD, heart failure and ethnicity, these findings remained robust, though the association was weaker in the high, unadjusted chest X-ray category.

“I think the take-home here is that, despite legitimate concerns about relying on chest X-ray on its own, because it does 'miss' lung cancer in at least around a fifth of cases, the test is useful because most patients present with symptoms that are in themselves low risk,” Bradley told MHE in an email interview. “For example, cough is the most common symptom, but because cough is so common, the risk of lung cancer in someone who sees their doctor with a cough is less than 1%.”

“This study provides evidence that primary care providers who organize chest X-ray more frequently for their patients with symptoms diagnose people with lung cancer at earlier stages of disease, and they have improved survival,” Bradley says.

Chest X-ray is already the recommended first-line test in primary care in most countries worldwide, Bradley says, except for “the minority of patients who are coughing blood (hemoptysis) who have a much higher risk and require prompt imaging with CT.”

“The findings of the study support a strategy of promoting uptake of chest X-ray in people who have common symptoms, particularly if they have smoked,” he adds. “But clinicians and patients need to remember that the test isn't perfect, some will need a CT even if chest X-ray is normal, and many of these symptoms can indicate other serious illnesses even if lung cancer isn't present.”

Despite the strong results, the authors admit that the study had certain shortcomings. Chest X-rays are not foolproof; they can miss around 20% of lung cancer cases, particularly for early-stage tumors. Additionally, the study only focused on symptomatic patients in the UK, as opposed to asymptomatic individuals who may have more frequent screenings for lung cancer, as is the case in some countries, including the US. This contextual difference is important, Bradley says, “as the National Lung Cancer Screening Trial did not show a benefit of chest x-ray in higher-risk populations who had not presented with symptoms.”

This research, funded by Cancer Research UK, is the first study to link chest x-ray rates with England’s national cancer registry, according to a news release. Healthcare professionals are encouraged to consider this simple and effective test for people experiencing symptoms, while remaining mindful of its limitations and the need for further investigation in certain cases.