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Old 03-06-2007, 05:19 PM
Dross Dross is offline
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Default Study shows no survival benefit for CT screening for lung cancer

The first report of an international study looking at computed tomography (CT) to screen current or former smokers for lung cancer found that screening did not reduce deaths from lung cancer. Although CT screening found nearly three times as many lung cancers as predicted, the researchers found that early detection and treatment did not lead to a corresponding decrease in advanced lung cancers or a reduction in deaths from lung cancer. The multi-center study, led by researchers at Memorial Sloan-Kettering Cancer Center, found no advantage to using CT screening on current or former smokers -- the population at highest risk for developing lung cancer. The findings appear in the March 7, 2007 issue of the Journal of the American Medical Association.

"Ours is the first study to ask whether detecting very small growths in the lung by CT is the same as intercepting cancers before they spread and become incurable. We found an answer and it was, 'NO'," said Peter B. Bach, M.D., M.A.P.P., a lung physician and epidemiologist at Memorial Sloan-Kettering and the study's first author. "Early detection and additional treatment did not save lives but did subject patients to invasive and possibly unnecessary treatments."

Beginning in 1998, 3246 asymptomatic men and women with a median age of 60 who had smoked or still smoked for an average of 39 years were screened for lung cancer with state-of-the-art multi-detector CT at either the Mayo Clinic in Minnesota, the H. Lee Moffitt Cancer Center & Research Institute in Florida, or the Instituto Tumori in Italy. Each study provided an initial CT scan and then at least three subsequent annual exams. The researchers followed the volunteers to see how many had cancers detected by screening and how many had surgery to remove them. They then used government death records to follow the study participants for five years to see if they died of lung cancer. The researchers compared what they saw to what statistical models predicted would happen without screening. The models were developed for this purpose by Dr. Bach and Colin B. Begg, Ph.D., Chairman of the Department of Epidemiology and Biostatistics at Memorial Sloan-Kettering, and have been shown to be accurate in study populations like the ones analyzed.

Over the course of the studies, screening found more than three times as many lung cancers as the number that would have been diagnosed without screening, and there were ten times as many surgeries performed for lung cancer compared to what was expected. This meant that as a direct result of the test, an additional 99 people were diagnosed with lung cancer and an additional 98 had lung surgery. However, the early detection and treatment did not change the death rate. There were 38 deaths due to lung cancer, and 39 would have occurred without screening.

"The purpose of large-scale screening is to save lives, but after five years of follow-up, our data provides no evidence that CT screening prevented deaths from lung cancer," said Dr. Begg, the paper's senior author. "Our findings are consistent with the results of earlier studies of lung cancer screening with chest x-rays, which showed no benefit to this type of screening for current and former smokers."

CT screening is not without risk. The radiation can become significant when the scans are repeated every year. Because the test is not very specific, it is known to have false positive results, which can lead to additional CT scans at full radiation doses and invasive procedures like lung biopsies. This study also suggests CT screening can lead to additional major surgeries to remove very small growths that look like lung cancer but do not pose a meaningful threat to the patient's health.

"With lung cancer the number one cause of cancer deaths in the United States, the medical profession continues to seek an effective and safe approach to prevent deaths from this disease. According to our study, CT screening may not be it," said Dr. Bach.

Dr. Kenny Lin
Former US Preventive Services Task Force staffer

The risk of developing cancer from the CT scan itself isn't trivial. An analysis published in the Archives of Internal Medicine found that a typical chest CT scan exposes patients to the radiation equivalent of more than 100 chest X-rays, and that at age 60, an estimated 1 in 1000 women or 1 in 2000 men would eventually develop cancer from that single scan. Although some imaging centers now use lower radiation doses, repeating these lower-dose CT scans annually still adds up. It hasn't been long enough since the conclusion of the NCI's lung cancer screening study to measure how much these scans increased the participants' risk for other cancers.


False alarms are extremely common. In the NCI's study, more than 96 percent of all positive results turned out to be false positives, and in a previous CT screening study, 1 in 3 patients had at least one false-positive result after undergoing only two CT scans. Of those patients, 1 in 14 needed an invasive lung biopsy to be sure they were cancer-free. Such diagnostic procedures for lung cancer can themselves be life-threatening.


A CT scan for lung cancer could find some other unrelated abnormality that will require further investigation; in the NCI's study, this occurred in about 1 in every 13 patients. You might think this is a good thing, but most of these abnormalities (known as "incidentalomas") turn out to be false alarms, too. In fact, in 2008 this very same Task Force decided against endorsing CT screening for colorectal cancer due to concerns that invasive testing to definitively diagnose all of the abnormalities that CT scans turn up could easily outweigh the cancer-prevention benefits.


Even if screening catches a true lung cancer early, there's no guarantee your prognosis will be better. This is due to "overdiagnosis," or the unnecessary diagnosis of a condition (typically cancer) that will never cause symptoms in a patient's lifetime, either because it's so slow-growing or the patient dies from some other cause. (Statistics show that most lifelong smokers will die from heart disease, not lung cancer.) An estimated 1 in 3 breast cancers detected by screening mammograms is overdiagnosed, and a 2007 study published in the journal Radiology suggested that the proportion of lung cancers overdiagnosed by CT scans could be as high or higher, especially in women. But because there's no way of knowing at the time of diagnosis if a lung cancer will be fatal, inevitably most of these patients will be needlessly subjected to the side effects of treatment - making the "cure" worse than the disease.


Last edited by gdpawel : 07-30-2013 at 11:45 AM. Reason: additional info
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Old 12-11-2013, 02:00 AM
gdpawel gdpawel is offline
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Default Overdiagnosis in Low-Dose Computed Tomography Screening for Lung Cancer

About 18% of lung cancers caught by low-dose CT screening were slow-growing tumors that wouldn't have affected patients during their lifetime, an analysis of the National Lung Screening Trial (NLST) showed.

That trial showed a mortality advantage to screening, but for every one lung cancer death prevented per 320 patients with screening in the trial, 1.38 cases of overdiagnosis would be expected, Edward F. Patz Jr., MD, of Duke University Medical Center, and colleagues found.

"These overdiagnosis cases represent an important potential harm of screening because they incur additional cost, anxiety, and morbidity associated with cancer treatment," they wrote online in JAMA Internal Medicine.

Patz and colleagues recommended that physicians include the risk of overdiagnosis in describing the risks of low-dose CT screening for lung cancer to patients.

While the findings may help shape patient expectations, they wouldn't likely shift the risk-benefit ratio much for individual patients, Patz suggested in an interview with MedPage Today.

Nor is the recent U.S. Preventive Services Task Force recommendation to screen high-risk patients annually likely to be affected, he argued.

"I don't think this will shift recommendations at all," he said. "It's just part of this entire puzzle we're trying to piece together, how we can best offer a mass screening program as public policy."

The American College of Radiology agreed, in a statement calling the overdiagnosis rate "modest" and in line with the projected rate with other types of cancer screening.

"Lung cancer screening using low-dose CT is the only test ever shown to reduce mortality in high-risk smokers, the leading cause of cancer death in the U.S. It does so cost effectively compared to other screening tests," the statement said. "Overdiagnosis is an expected part of any screening program and does not alter these facts."

Preparations for the lung cancer screening programs rolling out across the country should proceed as the medical community continues to address the issue of overdiagnosis, the ACR recommended.

The organization said it plans to proceed with its efforts to support those programs, which include forming appropriateness criteria and making a structured reporting and data collecting system to standardize methods.

Most programs appear to be following the NLST or modified versions of its criteria.

The trial randomized 53,454 men and women ages 55 to 74 with at least a 30 pack-year history of smoking to screening using low-dose CT or chest radiography.

During the median 6.4 years of follow-up, CT-based screening picked up 1,089 lung cancers compared with 969 in the chest x-ray arm.

Since the actual cancer rate was likely the same between the two well-matched groups, those extra cancers detected could have represented overdiagnosis, the researchers explained.

The excess cancer rates were 18.5% when calculated as a probability that the CT-detected cancer wouldn't have become clinically apparent during the screening phase if CT wouldn't have been done and 11% when calculated more from a public health perspective as the fraction of all lung cancer cases diagnosed in the study that wouldn't have been diagnosed then without CT screening.

The overdiagnosis rate was 31% when compared with no screening.

The probability that a tumor represented an overdiagnosis versus chest x-ray screening was also higher at 22.5% for non-small cell lung cancer and at 78.9% for bronchoalveolar lung cancer.

"These data raise the question as to the necessity and type of therapy required if a diagnosis of minimally invasive adenocarcinoma is established and challenge the diagnostic community to develop a classification scheme that could accurately phenotype all lung tumors," Patz's group wrote.

The 4 to 5 years of follow-up after screening "may not have been long enough to account for the lead time of all low-dose CT-detected cancers, particularly because tumor growth rates are quite variable and do not consistently follow classical expected exponential growth curves," the researchers cautioned.

Because CT screening found smaller, earlier stage tumors than chest x-ray, that arm would likely have had additional cancer rate "catch up" over time, so the overdiagnosis estimates "provide an upper bound on the true overdiagnosis rate associated with low-dose CT screening relative to chest radiology screening," they explained.

The key to reducing the harm of overdiagnosis will be to find biomarkers to separate out the indolent lung cancers, Patz suggested.

The research was supported by the National Institutes of Health through grants and contracts.

The researchers reported having no conflicts of interest to disclose.

Source: JAMA Internal Medicine

Reference: Patz EF Jr, et al "Overdiagnosis in low-dose computed tomography screening for lung cancer" JAMA Intern Med 2013; DOI:10.1001/jamainternmed.2013.12738.


Citation: "CT Screening Overdiagnoses Lung Cancer" MedPage Today December 9, 2013
Gregory D. Pawelski
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Old 05-02-2014, 11:53 AM
gdpawel gdpawel is offline
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Default Medicare advisory panel says no to Medicare coverage for Lung Cancer Screening

The Medicare Evidence & Coverage Advisory Committee (MEDAC) voted against recommending national Medicare coverage for annual screening for lung cancer with low-dose computed tomography (CT) in high-risk individuals.

The panel, composed mostly of clinicians, was asked to vote on a scale of 1 to 5 on whether they were confident that the benefits of such screening outweigh the harms in the Medicare population (persons older than 65 years). The mean score of the vote was 2, which shows low to intermediate confidence, according to press reports of the meeting.

Evidence considered by the panel included results from the National Lung Screening Trial, which show that CT screening significantly reduces lung cancer deaths (by 20% compared with chest x- rays). The results have been hailed as a great step forward for lung cancer and have led to many medical societies recommending screening, including the National Comprehensive Cancer Network (NCCN) and the American Cancer Society, among others. Last year, the United States Preventive Services Force (USPSTF) issued a grade B recommendation for annual CT screening for lung cancer.

Under the Affordable Care Act (ACA), any procedure that receives a grade B recommendation from the USPSTF has to be covered by private insurers without a copay. However, the ACA does not specify that Medicare has to do so.

But the Medicare population is exactly the population that could benefit from lung cancer screening, which is recommended for indivuduals aged 55 to 80 years who have a history of smoking (30 pack/year) and who are currently smoking or who quit within the last 15 years.

The Centers for Medicare & Medicaid Services (CMS) received and accepted 2 formal requests to initiate national Medicare coverage for lung cancer screening, which was followed by an open comment period. The formal requests came from Peter Bach, MD, director of the Center for Health Policy and Outcomes at the Memorial Sloan-Kettering Cancer Center in New York City, and Laurie Fenton Ambrose, president and CEO of the Lung Cancer Alliance.

In addition, a collection of more than 40 medical societies, including the Lung Cancer Alliance, the Society of Thoracic Surgeons, and the American College of Radiology (ACR), has petitioned the CMS to provide national Medicare coverage of lung cancer screening.

The latest development, yesterday's decision by the MEDAC panel to vote against recommending Medicare coverage for lung cancer screening, has come as a bit of a surprise and has already been condemned by the ACR, which warns that "lives may be lost" as a result.

However, the MEDAC panel recommendation is not binding.

The CMS is expected to issue a proposed decision on the issue by November 2014, and a final decision in February 2015.

Refusing Medicare coverage for lung cancer screening "penalizes many seniors and may result in lives lost," the ACR warns in a statement.

"Without national Medicare coverage for CT lung cancer screening, seniors face a 2-tier coverage system in which those with private insurance will be covered for these exams and many of their lives saved, while Medicare beneficiaries are left with lesser access to these exams and placed at increased risk of dying from lung cancer," commented Ella Kazerooni, MD, chair of the ACR Lung Cancer Screening Committee.

"We strongly urge CMS to act on the evidence and the USPSTF recommendations and provide full national coverage of CT lung cancer screening for high risk patients," the ACR said in a statement.

Citation: Panel Says No to Medicare Coverage for Lung Cancer Screening. Medscape. May 01, 2014
Gregory D. Pawelski
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Old 01-30-2017, 11:13 PM
gdpawel gdpawel is offline
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Default Lung Cancer Screening Program Finds A Lot That's Not Cancer

Richard Harris
January 30, 2017

Screening for lung cancer using low-dose CT scans can save lives, but at a cost: Tests frequently produce anxiety-producing false alarms and prompt unnecessary procedures.

A study from the Veterans Health Administration lays out the considerable effort required by both patients and doctors to undertake screening.

"I have heard people say 'what's the big deal, it's just a CT,' " says Dr. Linda Kinsinger, who ran the study at the VA. "But I think what we tried to show is it's a lot more than just a CT."

Federal officials and other medical groups recommend low-dose CT scans to look for lung cancer among people at risk, generally those over the age of 55 who have smoked at least the equivalent of two packs a day for 15 years. The tests typically cost $300, and they aren't always covered by insurance.

Screening does identify cancers, but in the vast majority of cases the test produces false alarms.

In the VA study, which was published Monday in JAMA Internal Medicine, 4,246 patients were eligible for screening. About half of them declined to take the test, even though it was offered at no cost.


Of those who took the test, about 55 percent of them were told that they had lung nodules, which often involved follow-up appointments and further scans. But very few of those nodules were actually real problems. In the end, the screeners identified 31 cases of lung cancer, about 20 of which were in the early, most treatable stage.

The study involved eight of the 150 or so VA hospitals, and was designed to assess the overall benefits and potential harms of setting up a screening program in a large medical institution.

So is it a good idea? "I think it's a close call," Kinsinger says.

There was a benefit to the 20 or so patients out of this large initial population who had their cancer detected while it was likely to be treatable. "But that has to be weighed against the amount of effort on the part of both patients and staff, and the anxiety, the worry, that a false alarm will cause among patients," she says.

"I think a lot of people have a much rosier view of screening in general than the facts bear out," says Dr. Rita Redberg, editor of JAMA Internal Medicine and a cardiologist at the University of California, San Francisco who wrote an editorial accompanying the study. "Very few people are actually helped by screening, and a lot of time there are a number of harms."


Another study published in the same issue found that many people getting CT screens are actually at low risk for lung cancer. Dr. Jinhai Huo and colleagues at the MD Anderson Cancer Center compared screening rates before and after 2011, the year of a key study that supported the idea of low-dose CT screening for lung cancer.


"Once a [radiology] center has the ability to do this screening, they like to use their technology to do as many people as possible," Redberg says, "and it seems that low-risk people who are really unlikely to get any benefit and are much more likely to get harmed are getting screened in higher numbers than in the high-risk people who are supposed to be screened."

Dr. Jorge Gomez, a spokesman for the American Lung Association and an oncologist at Mt. Sinai Hospital in New York, says that while screening low-risk people doesn't make sense on a population basis, it sometimes makes sense for individual patients.

And as for the experience at the VA, Gomez says medical teams that have learned to interpret the results of scans can generally weed out false-positive results without resorting to biopsies or other invasive follow-up tests.

"There is a concern for unnecessary procedures at institutions where they don't have the expertise in reading these scans," he says. And he acknowledges not everybody has the luxury of going to the top-of-the-line institutions that do this best.
Gregory D. Pawelski
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