An expert panel of chest physicians has updated its guidelines for low-dose CT lung cancer screening based on a review of results from various trials. The group presented its proposal at the American College of Chest Physicians (CHEST) annual meeting last month in Toronto.
Led by Dr. Peter Mazzone of the Cleveland Clinic, the members analyzed more than 3,000 publications and pulled out 57 that addressed the benefits and harms of low-dose CT screening according to the population, intervention, comparator, and outcome (PICO) format. They used these studies to answer key clinical questions and develop six graded recommendations and nine ungraded statements.
The chief guidelines for who should consider annual low-dose CT lung cancer screening are as follows:
- Age 55 to 77 years
- Have not already shown symptoms of lung cancer
- Have a smoking history of 30 or more pack-years
To a large degree, this outline reflects the major recommendations provided by the landmark National Lung Screening Trial (NLST) and the U.S. Preventive Services Task Force (USPSTF), although with slight differences in age restrictions.
A considerable section of the proposal elaborated on when physicians should not use low-dose CT to screen for lung cancer. This includes screening for asymptomatic smokers or former smokers who do not meet the age and smoking history criteria, even if they are at high risk based on clinical risk prediction calculators. The panel also does not recommend screening for people with health complications that either limit their life expectancy or make screening and cancer treatment intolerable.
In addition to these criteria, the panel suggested that screening programs should develop a comprehensive approach for managing nodules and incidental findings, maximize patient compliance with annual screening, and provide effective counseling and shared decision-making before screening.
Rather than wholly depend on CT exams to detect lung cancer, the panel further urged screening programs to find other ways to identify patients with symptoms suggesting lung cancer so that these patients could receive diagnostic, as opposed to screening, exams. The group cited several potential disadvantages of low-dose CT lung cancer screening as well: overdiagnosis, invasive biopsies when testing for cancer, and procedural complications.
"Evidence suggests that low-dose CT screening for lung cancer results in a favorable but tenuous balance of benefit and harms," the panel wrote. "The selection of screen-eligible patients, the quality of imaging and image interpretation, the management of screen-detected findings, and the effectiveness of smoking cessation interventions, can impact this balance."
The proposed guidelines are still under peer review and are subject to change during the process, the group noted.
