News Release: Research, School of Medicine

Dec. 4,  2008

Emory Researchers Caution Against Widespread CT Screening for Lung Cancer

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While screenings for cancers of the breast, colon and prostate have saved many lives, the complexity of lung cancer makes such screenings thus far unreliable and inconclusive in terms of reducing overall mortality, caution Emory University researchers.

Lung cancer is the top cause of cancer deaths in the United States for both men and women, with more than 160,000 deaths from lung cancer in the United States last year. Each year more than 5,000 Georgia residents are diagnosed with lung cancer, and approximately 4,250 of them die -- an almost 85 percent mortality rate.

Typically, those who have a history of moderate-to-heavy smoking, those who have been exposed to heavy second-hand smoke, or those who have been exposed to cancer-causing agents at work are at highest risk for lung cancers,

"Unfortunately, while the use of CT scans has helped to more quickly identify some forms of cancer, there is no evidence to date that screening of high risk individuals for lung cancer with a CT scan reduces the mortality of lung cancer," says Kay Vydareny, MD, professor of radiology in the Emory School of Medicine.

"A large recent trial in which Emory participated and that was sponsored by the National Cancer Institute will hopefully shed light on the effectiveness of CT lung scans," she says. 

This study is a 'controlled' study in which participants who enrolled were randomly chosen to have either a chest X-ray or a CT scan each year for three years and were then followed-up for five additional years.

Another recent national study that has received considerable attention, the International Early Lung Cancer Action Program (IELCAP), has many biases that could distort the findings. As part of the study, all patients receive a CT scan so that there is, in effect, no control group, says Vydareny.

"Most scientists believe that only a controlled study can truly answer this important question," she says. "Since the answer to this question is not known in high risk individuals who have smoked or who have spent a lot of time in close quarters with smokers, and who represent 90 to 95 percent of those with lung cancer, there is absolutely no indication at this time for persons to be voluntarily screened if they do not fall into one of these categories."  

According to Dan Miller, MD, Kamal A. Mansour Professor of Surgery in the Emory School of Medicine and director of the Thoracic Oncology Program, many smokers may ask why they should not get a CT scan to find out if they have lung cancer or are at greater risk.

"Very few of these patients will be told they have nothing to worry about," Miller says. "A few patients will be told that they have something that is very suspicious for lung cancer and that further tests should be performed. However, the vast majority will likely be told that they have small nodules in their lungs, which can't be called definitely either malignant (cancerous) or benign (non-cancerous)."

In this situation, he says the patient is typically followed for a period of two years with up to six CT scans to see if the nodules stay unchanged in size (and are therefore benign) or grow (and are therefore suspicious for cancer). Some of these patients, he says, will elect to have these nodules removed surgically. In either case, most of the nodules will turn out to be benign and the patient and his/her physician will have worried or undergone surgery needlessly.

"It is certainly an individual's choice whether they want to be screened for lung cancer with a CT scan if they have no symptoms," notes Miller. "However, it is important to make certain that such individuals have complete information and be well-informed before having such a scan. If a patient has symptoms, such as a persistent cough, weight loss, persistent hoarseness or trouble breathing, he or she should see a physician as soon as possible. Often these symptoms are due to something other than lung cancer, but more tests should be performed to make certain." 

What should a person at high-risk for lung cancer do? The answer that all physicians agree on is to stop smoking right now, the sooner the better. Or even better … don't start smoking ever, further reducing the chances of getting cancer or suffering from a stroke or heart attack as well.

"All physicians hope that there will be a test that can screen for early lung cancer and that the dismal prognosis of those with lung cancer will improve. Perhaps it will be screening with CT scans. Perhaps it will be a blood test," says Vydareny.  "That day hopefully will come, but it has not yet arrived."

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The Robert W. Woodruff Health Sciences Center of Emory University is an academic health science and service center focused on missions of teaching, research, health care and public service. Its components include schools of medicine, nursing, and public health; Yerkes National Primate Research Center; the Emory Winship Cancer Institute; and Emory Healthcare, the largest, most comprehensive health system in Georgia. The Woodruff Health Sciences Center has a $2.3 billion budget, 17,000 employees, 2,300 full-time and 1,900 affiliated faculty, 4,300 students and trainees, and a $4.9 billion economic impact on metro Atlanta.

Learn more about Emory’s health sciences:
Blog: http://emoryhealthblog.com
Twitter: @emoryhealthsci
Web: http://emoryhealthsciences.org

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