CT scan screening has no proven benefit in patients who are not at high risk for lung cancer, regardless of age, smoking history or other risk factors. Low dose chest CT screening has been found to reduce lung cancer mortality in a well-defined population of patients at high risk for lung cancer, defined by age 55-74, at least a 30-pack year history of tobacco use, and smoking within the last 15 years. However, screening is also associated with several harms, including false-negative and false-positive results, incidental findings, overdiagnosis (detecting indolent and clinically insignificant tumors that would not have been detected in the patient’s lifetime without screening), and cumulative exposure to radiation (which can cause cancer). Screening also leads to unnecessary anxiety and invasive procedures, which carry their own complications. Accordingly, it should not be used in patients who do not meet these strict criteria, nor in patients with a health problem that substantially limits life expectancy or the ability or willingness to have curative therapy.
Sources:
Canadian Task Force on Preventive Health Care, et al. Recommendations on screening for lung cancer. CMAJ. 2016 Apr 5;188(6):425-32. PMID: 26952527.
Moyer VA, et al. Screening for lung cancer: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2014 Mar 4;160(5):330-8. PMID: 24378917.
National Lung Screening Trial Research Team, et al. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med. 2011 Aug 4;365(5):395-409. PMID: 21714641.
O’Dowd EL, Baldwin DRBach PB, et al. Lung cancer screening-low dose CT for lung cancer screening: recent trial results and next steps. Br J Radiol. 2018 Oct;91(1090):20170460. PMID: 28749712.
Patz EF Jr, et al. Overdiagnosis in low-dose computed tomography screening for lung cancer. JAMA Intern Med. 2014 Feb 1;174(2):269-74. PMID: 24322569.