A prospective cohort evaluation of the sensitivity and specificity of the chest X-ray for the detection of lung cancer in symptomatic adults

• Published in: European journal of radiology 2021-11, Vol.144, p.109953, Article 109953
• Main Authors: Bhartia, Bobby S.K., Hatton, Nathaniel Luke Fielding, Aslam, Rehima, Bradley, Stephen H., Darby, Michael, Hamilton, William T., Hurst, Emily, Kennedy, Martyn P.T., Mounce, Luke T.A., Neal, Richard D., Shinkins, Bethany, Callister, Matthew E.J.
• Format: Article
• Language: English
• Subjects: Chest Radiograph; Diagnostic Accuracy; Lung Cancer
• ISSN: 0720-048X; 1872-7727
• DOI: 10.1016/j.ejrad.2021.109953

•The diagnostic accuracy of the CXR in detecting symptomatic lung cancer.•A positive CXR strongly increases the probability of lung cancer being present.•A negative CXR leads to a limited reduction of the probability of lung cancer.•The findings allow the risk of lung cancer following a negative test to be estimated. The accuracy of the chest x-ray (CXR) in the identification of lung cancer amongst symptomatic individuals is uncertain. To determine the diagnostic accuracy of the CXR for the detection of non-small cell carcinomas (NSCLC) and all primary intrathoracic malignancies. A prospective cohort study of consecutive CXR reports obtained within a primary care open access initiative. Eligibility criteria were symptoms specified by National Institute for Clinical Excellence as indicative of possible lung cancer and age over 50-yrs. A positive test was a CXR which led directly or indirectly to investigation with CT. The reference standards were malignancies observed within a one- or two-year post-test period. 8,948 CXR outcomes were evaluated. 496 positive studies led to a diagnosis of 101 patients with primary intrathoracic malignancy including 80 with NSCLC. Within two-years, a cumulative total of 168 patients with primary intrathoracic malignancies including 133 NSCLC were observed. The sensitivity and specificity for NSCLC were 76% (95 %CI 68–84) and 95% (95 %CI 95–96) within 1-year and 60% (95 %CI 52–69) and 95% (95 %CI 95–96) within 2-years. The 2-yr positive and negative likelihood ratios were 12.8 and 0.4. The results did not differ for NSCLC compared to all primary malignancies. Within this symptomatic population a negative test reduced the 2-year risk of lung cancer to 0.8%. A positive test strongly increases the probability of malignancy whereas a negative test does not conclusively exclude the disease. The findings allow the risk of malignancy following a negative test to be estimated.