• Low-dose CT screening recommended to reduce deaths from lung cancer

    February 2014

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    Yearly low-dose computed tomography (LDCT) screenings for those most at risk for lung cancer – older current and previous heavy smokers – are now recommended by the U.S. Preventive Services Task Force as a means of reducing the number of deaths from lung cancer, the nation’s leading cause of cancer-related death.

    Patient being prepared for CT scan.

    Patient being prepared for CT scan. 

    The Preventive Services Task Force released its recommendations in the December 2013 issue of the Annals of Internal Medicine. The move may help reduce the number of people dying from lung cancer by as much as 16 percent by finding the cancer earlier, when it is more easily treated. That was the finding of a large national study that provided the bulk of evidence reviewed by the task force.

    The task force, created in 1984, is an independent panel of volunteer national experts in prevention and evidence-based medicine tasked with improving the health of Americans through evidence-based screening and health promotion. Under the Patient Protection and Affordable Care Act, the task force must report annually to Congress and related agencies on priority preventive services.

    Lung cancer’s toll

    An estimated 160,000 people died from lung cancer in 2012, according to the American Cancer Society; about 200,000 are diagnosed with lung cancer each year. The lung CT screening is done with an X-ray machine that scans the body, using low doses of radiation to create a series of images that provide more details than a traditional chest X-ray image.

    Evidence suggests that the most common type of lung cancer – non-small cell – can be cured if it’s found early enough. But 90 percent of people with lung cancer die from the disease, largely because it’s generally found at an advanced stage, when it’s untreatable.

    The vast majority of lung cancer cases – as many as 85 percent – are caused by smoking. The risk increases according to how much and how long a person smokes. Aging also increases the risk for lung cancer – most lung cancers occur in people 55 and older. The best ways to reduce the risk for lung cancer are to not smoke and to avoid exposure to tobacco smoke. Those who quit smoking reduce their risk of developing and dying from lung cancer.

    “It’s clear that the longer and the more a person smokes, the greater their risk is for developing lung cancer,” said task force co-vice chair Michael LeFevre, MD, MSPH. “When clinicians are determining who would most benefit from screening, they need to look at a person’s age, overall health, how much the person has smoked, and whether the person is still smoking or how many years it has been since the person quit.”  

    8,000 studies reviewed

    Before making its recommendations, a Preventive Services Task Force systematically reviewed more than 8,000 studies. The largest study (as reported in an earlier Advances & Insights, January 3, 2011) was the National Lung Screening Trial (NLST) conducted at 33 U.S. sites. That study found annual LDCT screening resulted in a 16 percent reduction in deaths from lung cancer and a 6.7 percent reduction in death from all causes.

    The NLST looked at 53,454 former and current heavy smokers ages 55 to 74 who had no symptoms of disease when the study began in 2002. Participants had smoked at least 30 “pack years”: those who smoked one pack a day for 30 years, two packs a day for 15 years, or three packs a day for at least 10 years. Former smokers were included if they were 30 pack-year smokers who had stopped smoking within the previous 15 years.

    Participants were randomly assigned to undergo annual screening for three years with either LDCT scans or traditional chest X-rays. After the three rounds of screening, the participants were to be followed for five years. The trial was stopped early because the findings were so conclusive.

    The task force concluded that low-dose “CT scans more accurately identify early stage cancer than other screening tests” such as chest X-rays and sputum cytology and that “many lung cancer deaths can be prevented y screening high-risk people every year.” The task force noted that the benefits outweigh the potential harm of annual LDCT screenings.

    The risks of annual scans are that the tests can sometimes suggest a person has cancer, when in fact, there is no cancer. This is known as a “false positive.” Such findings cause worry and anxiety and may lead to unnecessary tests and procedures. Also, LDCT scans are specialized X-rays, so people are exposed to radiation; radiation from repeated scans over time may cause cancer in healthy people.

    Task force recommendations

    The Preventive Services Task Force recommends annual low-dose CT scans to screen for lung cancer in people who:
       • Are 55 to 80 years old, and
       • Have a 30 pack-year smoking history, and
       • Currently smoke or have quit within the past 15 years.

    Screening should be stopped once a person has not smoked for 15 years or has developed a health problem that limits life expectancy or the ability to undergo lung surgery.

    Similar recommendations

    Other highly regarded organizations have recently made similar recommendations for yearly LDCT scans, including the American College of Chest Physicians, the American Society of Clinical Oncology, the American Thoracic Society, the American Association for Thoracic Surgery, the American Cancer Society and the National Comprehensive Cancer Network.

Page last updated: 8/7/2015 1:07:37 PM
  • What the news means for you

    Finally, a tool for finding lung cancer early

    Ronald McGarry, MD, PhD
    Radiation Medicine

    McGarry, Ronald C., MD, PhDWe’ve long sought a way to find lung cancer early, when we have a greater chance of a cure with surgery alone. But traditional chest X-rays and other tests were not sensitive enough to pick up signs of early disease. It wasn’t until the National Lung Screening Trial (NLST) announced its findings in 2010 that we finally could say we have a test sensitive enough to find lung cancer before it has a chance to spread.

    “We have a test sensitive enough to find lung cancer before it’s had a chance to spread.” 

    After reviewing the NLST data and other research, the Preventive Services Task Force says the value of annual screening far outweighs any risk associated with radiation doses or concerns about unnecessary testing or false-positive findings (those that didn’t turn out to be cancer). This is good news, especially here in Kentucky where we have the highest incidences of lung cancer and of smoking in the country. This is the place where screening can make the difference.

    Treating lung cancer

    The gold standard of treatment is surgery to remove the lobe of the lung where the cancer is located followed by chemotherapy and radiation, if needed.

    If we can remove an early, small stage I cancer with surgery, we have a good chance for a cure. Unfortunately, about 90 percent of people who have lung cancer die from the disease largely because it’s found after the cancer has already spread (stages III and IV). That’s why finding a reliable screening tool such as low-dose CT scans is critical to saving lives.

    Lung cancer isn’t one of those cancers like cancer of the prostate where “watchful waiting” is advised; there is no such thing as a benign lung cancer. The only time lung cancer can be treated successfully is when it’s small; the three-year survival rate for untreated stage I lung cancer is only 10 percent. When someone is diagnosed with stage III lung cancer, there is only a 10-15 percent five-year survival rate.

    “While screening may save lives, the most effective action we can take to prevent lung cancer is to never start smoking, or, if already smoking, quit.” 

    For those who may not be surgical candidates, such as older patients or those who have other health problems, we offer a curative noninvasive treatment called stereotactic body radiation therapy (SBRT). This treatment is effective in medically inoperable stage I non-small cell lung cancer. The UK Markey Cancer Center is the Commonwealth’s only National Cancer Institute-designated cancer center and is one of only 10 centers nationwide participating in several clinical trials of this emerging form of treatment. We are the only center in the country studying the use of SBRT on patients with stage III lung cancer.

    Who should be screened?

    Talk to your doctor about the new screening guidelines to determine if you should be screened. If you are or were a heavy smoker and are between the ages of 55 and 80, you may benefit from a yearly annual CT scan. It’s important that you go to a reputable diagnostic center for your CT scan and that your physician is familiar with the diagnostic protocols for determining if an abnormality is actually cancer.

    With the Preventive Services Task Force’s recommendation, the cost should soon be covered by insurance companies and Medicare under the Affordable Care Act.

    As we move forward, the task force may expand its recommendations to include a wider range of people who might benefit from annual screening. Keep in mind that not all lung cancers found with screening will be early stage, and that the vast majority of abnormal findings turn out not to be cancer (false positives).

    Most importantly, while screening may save lives, the most effective action we can take to prevent lung cancer is to never start smoking, or, if already smoking, quit.

    Dr. McGarry is a radiation oncologist and a pioneer in use of stereotactic body radiation therapy (SBRT) for treatment of inoperable lung cancer. He is also clinical professor of medicine and vice chair of radiation medicine in the UK College of Medicine.

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