CT lung screening recommended for older smokers

The American Cancer Society has issued new guidelines recommending that people ages 55 to 74 who have a history of heavy smoking undergo annual CT lung scans.

The recommendations, published online late last week in CA: A Cancer Journal for Clinicians, specify that smokers within that age range, if they meet certain conditions, should consult with their physicians about testing. That criteria includes:

  • No signs or symptoms of lung cancer.
  • Current of former smoker with a 30-pack-year history.
  • Active smokers should be strongly urged to enter a smoking cessation program.
  • Former smokers must have quit within the past 15 years.
  • The patient should be generally healthy.

ACS further recommends that the physician should tell patients about the benefits, limitations and potential harm--such as a false-positive result--of screening, and should direct that the procedure should be done in a facility that has experience in lung cancer screening.

The ACS recommendations are based on studies about low-dose CT screening, including the National Lung Screening Trial. The trial included more than 53,000 current or past heavy smokers who met the criteria described above. A report published in the New England Journal of Medicine in August 2011 found that annual low-dose lung CT screening reduced deaths from lung cancer by 20 percent over chest X-rays.

Last May, the American College of Chest Physicians, the American Society of Clinical Oncology and the National Comprehensive Cancer Network also recommended lung CT screening for heavy smokers ages 55 to 74.

Richard Wender, M.D., chair of family and community medicine at Thomas Jefferson University Medical College, and 19 other colleagues from other leading U.S. academic centers, wrote in their recent recommendations that there are many questions that still remain about establishing a lung cancer screening guideline. For instance, they wondered, at what age should screening begin and end? And what are considered to be optimal screening intervals and issues concerning the performance characteristics of screening?

But, "despite these unresolved issues," they wrote, "the NLST demonstrated that there is an opportunity to reduce deaths from lung cancer in a high risk group of current and former smokers." Whether or not eligibility criteria in screening guidelines are broadened in the future will depend, they said, on "additional research and the development and validation of new risk assessment tools."

"Now that there is rigorous evidence supporting the value of screening for lung cancer with LDCT, it is important that the implementation of lung cancer screening proceeds in a manner that is focused on maximizing benefits and minimizing harms," the authors concluded. "At this time, there is sufficient evidence to support screening provided that the patient has undergone a thorough discussion of the benefits, limitations, and risks, and can be screened in a setting with experience in lung cancer screening."

Ella Kazerooni, M.D., professor of radiology at the University of Michigan in Ann Arbor, told AuntMinnie.com that it's a soft recommendation toward screening a high-risk population.

"It's not a definite recommendation that the NLST-type people should go out and get screened," she said. "It's more like a recommendation that's trying to balance waiting for the NLST cost-effectiveness analysis to come forward, yet trying to do something to help those who may potentially benefit from screening to go out and learn more so that they may potentially want to get screened."

For more:
- read about the recommendations
- read about the National Lung Screening Trial
- see the August 2011 NEJM report about the NLST
- read the article on AuntMinnie.com