• Low-Dose CT Scan May Be Effective Screening Tool for Lung Cancer in People at High Risk

    Lung cancer is the leading cause of cancer deaths. As with most cancers early discovery may be a key factor in decreasing mortality and improving long-term survival. The earlier the cancer is found the more likely the treatment will be able to stop or delay the spread of cancer or prevent extensive local damage. Unfortunately, outward signs of lung cancer may not develop until it is in later stages. An effective screening program to find lung cancer in its early stages may help reduce mortality rates or increase the length of survival. Because of the strong link between smoking and lung cancer many lung cancer-screening programs focus on people with long history of smoking.
    Researchers on the National Lung Screening Research Team investigated if a low-dose computed tomography (CT) scan could effectively screen for lung cancer in long-term smokers. A CT scan is type of x-ray that can take cross-sectional images of the inside of the body. The scan can make clearer images of organs than standard x-rays. The study, published in New England Journal of Medicine, found that screening with the CT scan decreased the rate of death overall and the rate of death due to lung cancer compared to screening with a standard chest x-ray.

    About the Study

    The randomized trial included 53,454 patients between ages 55-74 years with at least a 30-pack year history of smoking. Pack years is a tool physicians use to estimate lifetime exposure to tobacco. It takes into account number of cigarettes smoked per day and the number of years of smoking. The pack year history in this trial is considered a high risk for the development of lung cancer. The participants were randomized to three annual screenings with either low-dose CT scan or single view chest x-ray. They were followed for 6.5 years for the development of lung cancer and death. About 93%-95% of participants in both groups completed all three screenings.
    Results from scans include
    • abnormalities (positive screen) found in initial screen in 27.3% with CT scan vs. 9.2% with x-ray
    • positive screens over all 3 rounds in 24.2% with CT scan vs. 6.9% with x-ray
    • false positive (scan indicated something when there was nothing) rate 96.4% with CT scan vs. 94.5% with x-ray
    • lung cancer diagnosed in 1,060 patients with CT scan vs. 941 patients with x-ray
    Despite the higher incidence of diagnosed cancers, CT scans were associated with lower rates of death from lung cancer and death overall:
    • lung cancer deaths occurred in 1.33% of patients with CT scan vs. 1.66% of patients with x-ray (statistically significant difference)
    • death from any cause occurred in 7.02% of patients with CT scan vs. 7.48% of patients with x-ray (statistically significant difference)
    The trial was stopped early because the CT scan was found to be significantly better during an interim analysis.

    How Does This Affect You?

    Large randomized trials are generally considered a very reliable form of research. More trials will be done to assess the benefits and risks of lung cancer screening but CT scan appears to be a more reliable form of screening than plain chest x-ray in high-risk patients. The benefits found in this trial can only be applied to the types of participants in this trial, high-risk smokers aged 55-74 years. Earlier trials assessing chest x-rays found that frequent chest x-rays were not associated with decreased mortality. Since the CT scan was compared to chest x-rays it may have overestimated the benefits of CT scans. Further trials comparing to other screening methods will help clarify CT scan benefits.
    Although there is still some research to be done, the CT scan appears to be an effective screening option for people at high-risk. The CT scan in general has been used for several health issues and is generally considered safe despite some radiation exposure. The American Lung Association adjusted their screening guidelines based on this trial. The advisory suggests that people aged 55-74 years with at least 30 pack-year smoking history can undergo low-dose CT scanning to help detect lung cancer early. If you fit into this group, discuss the risks and benefits of screening with your doctor.

    RESOURCES

    American Lung Association http://www.lung.org/

    National Cancer Institute http://www.cancer.gov/

    References

    The National Lung Screening Trial Research Team. Reduced Lung-Cancer Mortality with Low-Dose Computed Tomographic Screening. N Engl J Med 2011; 365:395American Lung Association. ALA Provides Guidance on Lung Cancer Screening. Available at: http://www.lung.org/lung-disease/lung-cancer/lung-cancer-screening-guidelines/. Accessed May 8, 2012.

    Revision Information

  • Join WellZones today.

    Make a Change For LifeLearn more

    Wellmont LiveWell is creating a new tradition of wellness in the mountains by providing individuals with tools and encouragement to live healthier lifestyles.

  • HeartSHAPE Spotlight

    At risk for a heart attack? Learn more

    Fight heart disease early and prevent heart attacks with HeartSHAPE® - a painless, non-invasive test that takes pictures of your heart to scan for early-stage coronary disease.

  • Calories and Energy Needs

    Calorie NeedsLearn more

    How many calories do you need to eat each day to maintain your weight and fuel your physical activity? Enter a few of your stats into this calculator to find out.

  • Ideal Body Weight

    Ideal Body WeightLearn more

    Using body mass index as a reference, this calculator determines your ideal body weight range. All you need to do is enter your height.

  • Body Mass Index

    Body Mass IndexLearn more

    This tool considers your height and weight to assess your weight status.


  • Can we help answer your questions?

    Wellmont Nurse Connection is your resource for valuable health information any time, 24 hours a day, seven days a week. Speak to a Nurse any time, day or night, at (423) 723-6877 or toll-free at 1-877-230-NURSE.