In an ongoing observational study appearing Thursday in the New England Journal of Medicine, researchers report that lung cancer can be detected at its very earliest stage in 85% of patients using annual low-dose computed tomography (CT) screening.
Researchers believe that such screening would dramatically decrease the number of deaths from lung cancer, the No. 1 cause of cancer deaths in the U.S.
The study was launched by a team of researchers at NewYork-Presbyterian Hospital/Weill Cornell Medical Center (New York) in 1993 and has expanded into an international collaboration of 38 institutions in seven countries.
The International Early Lung Cancer Action Project (I-ELCAP) is the largest, long-term study to determine the usefulness of annual screening by CT, the institutions said.
"We believe this study provides compelling evidence that CT screening for lung cancer offers new hope for millions of people at risk for this disease and could dramatically reverse lung cancer death rates," said Claudia Henschke, MD, PhD, lead author and principal investigator, chief of the chest imaging division at New York-Presbyterian/Weill Cornell, and professor of radiology and cardiothoracic surgery at Weill Cornell Medical College .
The medical center said that Stage I lung cancer is the only stage at which cure by surgery is likely. While survival rates have been climbing for other forms of cancer, survival rates for lung cancer have continued to be "dismal," it said.
About 95% of the 173,000 people diagnosed each year die from the disease — more than breast, prostate and colon cancer combined. A key reason: More often than not, lung cancer is diagnosed at an advanced stage, when patients are least likely to respond to treatment.
Among the 31,567 people in the study, CT screening detected 484 people who were diagnosed with lung cancer, 412 of whom were Stage I. All the patients in that group who chose not to be treated died within five years.
Overall, the estimated 10-year survival rate for the 484 participants in lung cancer was 80%. The participants were 40 and older and at risk for lung cancer due to a history of cigarette smoking, occupational exposure to asbestos, beryllium, uranium or radon, or exposure to secondhand smoke.
The method for scanning used in the study — spiral CT, which is low-dose CT scan that can gather many images in seconds — ranges from $200 to $300 in cost, the medical center said. Treatment of Stage I lung cancer is "less than half" the cost for those receiving treatment for late-stage cancer, it said. It said estimates of the "cost-effectiveness" of CT screening for lung cancer are "similar or better" than those for mammography screening for breast cancer.
Asked concerning the major impact of the study, Henschke told Medical Device Daily: "Well, I hope that there is a discussion between people who think they're at risk of lung cancer and their doctor[s] and [they are] being guided as to whether they should have a CT scan."
Henschke also hopes there will be centers established that are "designated and knowledgeable in all aspects of the screening, just like there are for mammography — where they are good at reading film, they know how to do the workup properly and the treatment."
The human touch is also important, she said, for those at high risk who may be seeking screening and possibly treatment by "keeping the people who are going through this and reassuring them while they are going through this that there is nothing to worry about, or saying you really need to have further diagnostic procedures."
Robert Smith, PhD, director of screening for the American Cancer Society 's (ACS; Atlanta), called the study findings "encouraging and add to the knowledge base that is building related to the value of screening for lung cancer."
He called the work by Henschke and others "a solid, well-established program that has a long track record of international leadership in developing the algorithms for screening and management of small lung lesions detected on CT."
"The study shows that use of a powerful imaging tool, spiral CT, finds lung cancers when they are very small, and when prognosis is measurably better than when tumors are larger and advanced."
However, he said in an ACS statement that the study has "some limitations," for instance, as an observational study of volunteers vs. a randomized study. This means that less than might be desired is known about the subjects, such as how well they represent a high risk population most needing regular screening.
"If they are healthier on average, then those results could be more favorable than we ultimately would expect if screening were to be recommended to all adults with a significant smoking history," he said.
Rick Kellerman, MD, president of the American Academy of Family Physicians (AAFP; Leawood, Kansas), told MDD that while the study does add to the "body of knowledge" in screening for lung cancer, the lack of a control group is a "flaw."
"We're learning to be more skeptical in medicine," Kellerman said, noting that observational studies on estrogen and hormone replacement therapy suggested such therapy be given to women, but that in later randomized, controlled studies, HRT was shown to have significant health dangers.
"I think it's an interesting study, but I think we're going to have to wait for further studies to really change practice patterns. Patients need to be aware of both sides of the issue."
Another concern he cited is that the skill at reading CT scans and the resolution available on CT scanners may vary around the country and that in a study like I-ELCAP, investigators typically "have the highest quality scans and are skilled at reading the scans."
The "bottom line," he said, is: "People shouldn't smoke, and I think one of the fallacies that's going to come out of this is people will say, 'Well, I can go ahead and smoke because now we can detect lung cancer early,' without thinking smoking is not just lung cancer. It's also emphysema, it's heart disease, it's throat cancer."
Those in the business of selling CT devices welcomed the study.
"I think the findings that were reported are very encouraging, and they add to the clinical value of the evidence [already available], and that's exactly what we were waiting for," said Bob Beckett, global product manager, MI & CT Diagnostic Oncology Applications, GE Healthcare (Waukesha, Wisconsin).
Beckett noted that it is a multi-center trial, and that the findings could be duplicated across institutions, making it "so powerful."
Beckett said those at high risk for lung cancer will be "more aggressive" with their doctors in asking for the procedure, and family practitioners will have to "be prepared to address the patients' knowledge of this [study] information."
Both Beckett and Praveen Nadkarni, MD, clinical business manager for SiemensMedical Solutions (Malvern, Pennsylvania), said the study overcomes the historical concern of false positives in lung scanning by providing protocols for additional CT scans, at specific intervals, following discovery of a suspicious lung node.
Last week, Siemens, which assisted researchers in the I-ELCAP study, reported that it received the approval letter from the FDA for its syngo Lung CAD device, which Nadkarni said cuts down on the time that radiologists must spend reading scans for lung cancer.
The system, he said, aids radiologists in detecting location and size of nodules, which can be benign, and can be used both for disease detection and monitoring of chemotherapy for patients already diagnosed.