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Lung cancer trial results show mortality benefit with low-dose CT:

Twenty percent fewer lung cancer deaths seen among those who were screened with low-dose spiral CT than with chest X-ray

The National Cancer Institute (NCI) is today releasing initial results from a large-scale test of screening methods to reduce deaths from lung cancer by detecting cancers at relatively early stages.

The National Lung Screening Trial (NLST), a randomized national trial involving more than 53,000 current and former heavy smokers ages 55 to 74, compared the effects of two screening procedures for lung cancer -- low-dose helical computed tomography (CT) and standard chest X-ray -- on lung cancer mortality and found 20 percent fewer lung cancer deaths among trial participants screened with low-dose helical CT. The NLST was sponsored by NCI, a part of the National Institutes of Health, and conducted by the American College of Radiology Imaging Network (ACRIN) and the Lung Screening Study group. A paper describing the design and protocol of the NLST, “The National Lung Screening Trial: Overview and Study Design” by the NLST research team, was published yesterday by the journal Radiology and is openly available at http://radiology.rsna.org/cgi/content/a ... l.10091808.

“This large and well-designed study used rigorous scientific methods to test ways to prevent death from lung cancer by screening patients at especially high risk,” said Harold Varmus, M.D., NCI Director. “Lung cancer is the leading cause of cancer mortality in the U.S. and throughout the world, so a validated approach that can reduce lung cancer mortality by even 20 percent has the potential to spare very significant numbers of people from the ravages of this disease. But these findings should in no way distract us from continued efforts to curtail the use of tobacco, which will remain the major causative factor for lung cancer and several other diseases.”

National lung Screening Trial LogoThe NCI’s decision to announce the initial findings from the NLST was made after the trial’s independent Data and Safety Monitoring Board (DSMB) notified the NCI director that the accumulated data now provide a statistically convincing answer to the study’s primary question and that the trial should therefore be stopped. A fuller analysis, with more detailed results, will be prepared for publication in a peer-reviewed journal within the next few months. Participants in the NLST are being notified individually of the findings by the study’s investigators. The participant notification letter, as well as the DSMB letter, can be viewed at http://www.cancer.gov/clinicaltrials/no ... rials/nlst.

Starting in August 2002, the NLST enrolled about 53,500 men and women at 33 trial sites nationwide over a 20 month period. Participants were required to have a smoking history of at least 30 pack-years and were either current or former smokers without signs, symptoms, or history of lung cancer. Pack-years are calculated by multiplying the average number of packs of cigarettes smoked per day by the number of years a person has smoked.

Participants were randomly assigned to receive three annual screens with either low-dose helical CT (often referred to as spiral CT) or standard chest X-ray. Helical CT uses X-rays to obtain a multiple-image scan of the entire chest during a 7 to 15 second breath-hold. A standard chest X-ray requires only a sub-second breath-hold but produces a single image of the whole chest in which anatomic structures overlie one another. Previous efforts to demonstrate that standard chest X-ray examinations can reduce lung cancer mortality have been unsuccessful.

The trial participants received their screening tests at enrollment and at the end of their first and second years on the trial. The participants were then followed for up to another five years; all deaths were documented, with special attention given to the verification of lung cancer as a cause of death. At the time the DSMB held its final meeting on October 20, 2010, a total of 354 deaths from lung cancer had occurred among participants in the CT arm of the study, whereas a significantly larger 442 lung cancer deaths had occurred among those in the chest X-ray group. The DSMB concluded that this 20.3 percent reduction in lung cancer mortality met the standard for statistical significance and recommended ending the study.

“This is the first time that we have seen clear evidence of a significant reduction in lung cancer mortality with a screening test in a randomized controlled trial. The fact that low-dose helical CT provides a decided benefit is a result that will have implications for the screening and management of lung cancer for many years to come,” said Christine Berg, M.D., NLST project officer for the Lung Screening Study at NCI.

An ancillary finding, which was not the main endpoint of the trial’s design, showed that all-cause mortality (deaths due to any factor, including lung cancer) was 7 percent lower in those screened with low-dose helical CT than in those screened with chest X-ray. Approximately 25 percent of deaths in the NLST were due to lung cancer, while other deaths were due to factors such as cardiovascular disease. Further analysis will be required to understand this aspect of the findings more fully.

The NCI and its partners conducted this trial to obtain the most reliable results possible about the potential benefits of lung cancer screening. Others will begin to use the extensive data from this trial to conduct further analyses and to propose clinical guidelines and policy recommendations for lung cancer screening.

“The results of this trial provide objective evidence of the benefits of low-dose helical CT screening in an older, high-risk population and suggest that if low-dose helical CT screening is implemented responsibly, and individuals with abnormalities are judiciously followed, we have the potential to save thousands of lives,” said Denise Aberle, M.D., NLST national principal investigator for ACRIN. “However, given the high association between lung cancer and cigarette smoking, the trial investigators re-emphasize that the single best way to prevent lung cancer deaths is to never start smoking, and if already smoking, to quit permanently.”

The possible disadvantages of helical CT include the cumulative effects of radiation from multiple CT scans; surgical and medical complications in patients who prove not to have lung cancer but who need additional testing to make that determination; and risks from additional diagnostic work-up for findings unrelated to potential lung cancer, such as liver or kidney disease. In addition, the screening process itself can generate suspicious findings that turn out not to be cancer in the vast majority of cases, producing significant anxiety and expense. These problems must, of course, be weighed against the advantage of a significant reduction in lung cancer mortality.

It should also be noted that the population enrolled in this study, while ethnically representative of the high-risk U.S. population of smokers, was a highly motivated and primarily urban group that was screened at major medical centers. Thus the results may not accurately predict the effects of recommending low-dose helical CT scanning for other populations.


Copies of the DSMB and NLST participant letters can be found on the NLST site at http://www.cancer.gov/clinicaltrials/no ... rials/nlst.

For a Q&A on the NLST, please go to http://www.cancer.gov/newscenter/qa/2002/nlstqaQA.

For a Fact Sheet on the NLST, please go to http://www.cancer.gov/newscenter/pressr ... TFastFacts.

For more information on lung cancer and screening, please go to http://www.cancer.gov/cancertopics/types/lung.

“The National Lung Screening Trial: Overview and Study Design" has been published by Radiology. This paper is openly available at http://radiology.rsna.org/cgi/content/a ... l.10091808.

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  • 2 weeks later...

"Long-awaited results from a big federal study show that screening smokers and former smokers with CT scans cuts the risk of dying from lung cancer by 20%. But many questions remain about how these findings should be applied to more than 90 million Americans who smoke or once did."

Researchers saw a 20% relative difference in lung cancer death rates. However, the absolute difference iin death rates was much less than two percent, because of the small number of few lung cancer deaths in either the spiral CT (354 or 1.32%) or x-ray (442 or 1.65%) group compared to the size of the total trial population (53,500).

Putting a spotlight on relative differences in rates usually magnifies the effects of an intervention. Absolute numbers - and the number of people that need to undergo the intervention in order for at least one to benefit - should get at least equal billing in order to put trial results into perspective.

Heavy smokers in this trial who were offered CT scans had a 20% lower rate of death from lung cancer than those offered chest x-rays (354 vs 442). But, because so many smokers were in this trial, the lung cancer death rate in each group was less than 2%. The absolute difference is 1.32% vs 1.65%).

The National Cancer Institute reported that 300 smokers would have to undergo screening in order for one life to be extended, at $300 to $1,000 a scan. And screening can lead to additional tests and treatments. Like alone, the false positive rate in the study was a highly 25%. Who know how many repeat CT scans, lab test and thoracotomies were generated as a result.

While CT scans are painless, they expose patients to radiation that can potentially cause new cancers. It is possible that a person scanned frequently for lung cancer could develop breast cancer as a result. The screening could lead to more potentially dangerous surgeries.

And screenings don't diagnose cancer. While screenings can detect potential problems, doctors need to retrieve actual cells to confirm cancer. Making an incision through the ribs to perform a lung biopsy is a serious operation and poses significant risks of its own.

http://acspressroom.wordpress.com/2010/ ... it-begins/

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Sloan-Ketterings' Dr. Peter Bach wrote a column (CT Scam: Don't believe the hype about lung-cacer screenings") in Slate on the evidence, the harms, the costs and the marketing that has exploded all over the country after this National Lung Screening Trial results were published.


David Sampson, the American Cancer Society's director of medical and scientific communications, wrote on the ACS blog:

"It's only been a few days since researchers released preliminary results of a major trial of early detection of lung cancer in heavy smokers using CT scans. At the time, the American Cancer Society and others (including the authors themselves) expressed cautious optimism, with emphasis on the cautious, saying that although enormously promising, the data was not enough to call for routine use of this screening test, even in heavy smokers. But as we've discussed here, not everyone could resist the pull of touting the "good news" with little balance.

But our greatest fear was that forces with an economic interest in the test would sidestep the scientific process and use the release of the data to start promoting CT scans. Frankly, even we are surprised how quickly that has happened.

Last night, as he worked quietly in his home office, our Chief Medical Officer sat wide-eyed as he listened to an advertisement on an Atlanta radio station touting the results of the study to promote a local hospital's lung cancer screening program.

This morning, we were made aware of a press release from a group of doctors in Los Angeles promoting these scans. It actually appeared the day the news came out. It says:

"...this study should once and for all settle the controversy regarding the utility of screening CT of the lungs in saving lives."

As Dr. Len Lichtenfeld discussed in his blog, there is still much to discuss and learn about the test. And if you are someone who meets the criteria similar to people who participated in this study, then a scan might be worth considering. But before you do that, it would be wise to have a conversation with your health professional and consider whether screening is right for you. But oversimplifying these difficult issues in the pursuit of a compelling story or of paying clients is a disservice to public health.

http://www.cancer.org/AboutUs/DrLensBlo ... -Leap.aspx

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any insight on other types of early detection? I keep hearing talk about blood tests and also had been hearing about a type of Sputum or saliva test??

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One of the most promising approaches that may deal with early detection of cancer is Proteomics (protein expression analysis), the study of proteins (or fingerprints of proteins) in the cells, tissues and body fluids. Then there is a branch of proteomics called phosphoproteomics that identifies, catalogs and characterizes proteins containing a phosphate group as a post-translational modification. Phosphoproteins could be cancer markers useful to cancer diagnostics. It may be possible to mine the tumor phosphoproteome for potential biomarkers.

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  • 3 months later...

The realm of cancer early detection is just in the image scanning realm. Dr. Robert Nagourney of Rational Therapeutics, described a novel application of the cell search technology developed by Veridex, LLC (a subsidiary of Johnson & Johnson) that may provide an extemely sensitive tool for the early detection of cancer. Four major cancer centers in the United States are conducting an analysis to determine the accuracy of this method for early diagnosis.

Over recent years, it has been recognized that cancer patients circulate small numbers of tumor cells in their blood. Using microbead technology, these tumor cells can be isolated from the blood stream and characterized. The original application of the technology was a prognostic marker by which patients with breast, colorectal or prostate cancers and high levels of circulating tumor cells, fell in the “high-risk” groups. This provides a new opportunity for early diagnosis.

As we speculate on the ramifications of this discovery, certain questions are raised. The most immediate being: What to do with the data? It has previously been suggested that many cancers arise 20 or 30 years before they are clinically detected. Malignant populations measuring in the hundreds of thousands, millions or even hundreds of millions, may still lie below the radar screen of modern diagnostic tools.

If we have the capacity to identify patients 10 or 20 years before their cancers can be clinically detected, would we then begin therapy decades before clinical disease arises? If so, what treatments will we administer? Will the early detection of cancer cells be associated with the further characterization of tumors, such that targeted agents can be utilized to eliminate these clones at their earliest inception?

It will be interesting to see how we answer the questions that arise.

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