According to the Centers for Disease Control and Prevention, lung cancer is the third-most common cancer in the United States and the leading cause of cancer deaths in both men and women. Approximately, 150,000 Americans die every year from this disease.
Dr. Linda Girgis
In fact, it has been shown that low-dose CT scan screening can reduce lung cancer deaths by 20%-30% in high-risk populations.
In the United States, low-dose CT scan screening for lung cancer has largely become the norm. In July 2021, CHEST released new clinical guidelines. These guidelines cover 18 evidence-based recommendations as well as inclusion of further evidence regarding the benefits, risks, and use of CT screening.
In doing the risk assessment of low-dose CT scan as a method of lung cancer screening, meta-analyses were performed on evidence obtained through a literature search using PubMed, Embase, and the Cochrane Library. It was concluded that the benefits outweigh the risks as a method of lung cancer screening and can be utilized in reducing lung cancer deaths.
Low-dose CT scan screening was recommended for the following patients:
- Asymptomatic individuals aged 55-77 years with a history of smoking 30 or more pack-years. (This includes those who continue to smoke or who have quit in the previous 15 years. Annual screening is advised.)
- Asymptomatic individuals aged 55-80 years with a history of smoking 20-30 pack-years who either continue to smoke or have quit in the previous 15 years.
- For asymptomatic individuals who do not meet the above criteria but are predicted to benefit based on life-year gained calculations.
Don’t screen these patients
CT scan screening should not be performed on any person who does not meet any of the above three criteria.
Additionally, if a person has significant comorbidities that would limit their life expectancy, it is recommended not to do CT scan screening. Symptomatic patients should have appropriate diagnostic testing rather than screening.
Additional recommendations from the updated guidelines include developing appropriate counseling strategies as well as deciding what constitutes a positive test.
A positive test should be anything that warrants further evaluation rather than a return to annual screening. It was also advised that overtreatment strategies should be implemented. Additionally, smoking cessation treatment should be provided.
CHEST suggested undertaking a comprehensive approach involving multiple specialists including pulmonologists, radiologists, oncologists, etc. Strategies to ensure compliance with annual screening should also be devised, the guidelines say.
USPSTF’s updated guidelines
It should be noted that the U.S. Preventative Task Force released their own set of updated guidelines in March 2021. In these guidelines, the age at which lung cancer screening should be started was lowered from 55 years to 50 years.
Also, the USPSTF lowered the minimum required smoking history in order to be screened from 30 to 20 pack-years. Their purpose for doing this was to include more high-risk women as well as minorities.
With the changes, 14.5 million individuals living in the United States would be eligible for lung cancer screening by low-dose CT scan, an increase of 6.5 million people, compared with the previous guidelines.
While only small differences exist between the set of guidelines issued by CHEST and the ones issues by the USPSTF, lung cancer screening is still largely underutilized.
One of the barriers to screening may be patients’ lacking insurance coverage for it. As physicians, we need to advocate for these screening tools to be covered.
Other barriers include lack of patient knowledge regarding low-dose CT scans as a screening tool, patient time, and patient visits with their doctors being too short.
Key message
Part of the duties of physicians is to give our patients the best information. We can reduce lung cancer mortality in high risk patients by performing annual low-dose CT scans.
Whichever set of guidelines we chose to follow, we fail our patients if we don’t follow either set of them. The evidence is clear that a low-dose CT scan is a valuable screening tool to add to our practice of medicine.
Dr. Girgis practices family medicine in South River, N.J., and is a clinical assistant professor of family medicine at Robert Wood Johnson Medical School, New Brunswick, N.J. You can contact her at fpnews@mdedge.com.