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A blood test so sensitive that it can spot a single cancer cell among billions of healthy ones is moving one step closer to being available at physicians' offices.

A blood test so sensitive that it can spot a single cancer cell among billions of healthy ones is moving one step closer to being available at physicians' offices. Boston scientists who invented the test and healthcare giant Johnson & Johnson (New Brunswick NJ) announced that they are joining forces to bring it to market. Four big cancer centers also will start studies using the experimental test this year. Stray cancer cells in the blood mean that a tumor has spread or is likely to, many doctors believe. A test that can capture such cells has the potential to transform care for many types of cancer, especially breast, prostate, colon and lung. Initially, doctors want to use the test to try to predict what treatments would be best for each patient's tumor and find out quickly if they are working. "This is like a liquid biopsy" that avoids painful tissue sampling and may give a better way to monitor patients than periodic imaging scans, said Dr. Daniel Haber, chief of Massachusetts General Hospital's cancer center and one of the test's inventors.

Ultimately, the test may offer a way to screen for cancer besides the mammograms, colonoscopies and other less-than-ideal methods used now. "There's a lot of potential here, and that's why there's a lot of excitement," said Dr. Mark Kris, lung cancer chief at Memorial Sloan-Kettering Cancer Center in New York. He had no role in developing the test, but Sloan-Kettering is one of the sites that will study it this year. Many people have their cancers diagnosed through needle biopsies. These often do not provide enough of a sample to determine what genes or pathways control a tumor's growth. Or the sample may no longer be available by the time the patient gets sent to a specialist to decide what treatment to prescribe. Doctors typically give a drug or radiation treatment and then do a CT scan two months later to look for tumor shrinkage. Some patients only live long enough to try one or two treatments, so a test that can gauge success sooner, by looking at cancer cells in the blood, could give patients more options.

The only test on the market now to find tumor cells in blood--CellSearch, made by J&J's Veridex unit--just gives a cell count. It doesn't capture whole cells that doctors can analyze to choose treatments. Interest in trying to collect these cells soared in 2007, after Haber and his colleagues published a study of Mass General's test. It is far more powerful than CellSearch and traps cells intact. It requires only a couple of teaspoons of blood and can be done repeatedly to monitor treatment or determine why a drug has stopped working and what to try next. "That's what got the scientific community's interest," Kris said. Doctors can give a drug one day and sample blood the next day to see if the circulating tumor cells are gone, he explained. The test can find one cancer cell in a billion or more healthy cells, said Mehmet Toner, a Harvard University bioengineer who helped design it.

People with breathing problems that disrupt their sleep were less tired after three weeks of treatment with a breathing device compared to those treated with a placebo, US researchers said. The findings show that regular use of treatment with continuous positive airway pressure (CPAP) masks reduces fatigue caused by obstructive sleep apnea, a chronic disorder that affects 12 million Americans. Sleep apnea raises the risk of high blood pressure, heart attack, stroke, irregular heartbeat and diabetes. It occurs when soft tissue in the back of the throat collapses during sleep, blocking the airway and causing the brain to rouse the sleeper, who gasps for air--a cycle that can occur as many as 30 times in an hour. CPAP disrupts this cycle by providing a steady stream of air through a mask that keeps the airway open during sleep. Companies that make CPAP treatments include Graymark Healthcare (Oklahoma City OK) and ResMed Inc. (Poway CA).

"These results are important as they highlight that patients who comply with CPAP therapy can find relief from fatigue and experience increases in energy and vigor after a relatively short treatment period," said Lianne Tomfohr of San Diego State University and the University of California, San Diego, whose study appears in the journal Sleep. Several studies have shown that CPAP treatment can reduce other health risks, such as lowering the risk of stroke, but few have studied the impact on fatigue, which can reduce work performance and increase the risk of accidents.

The blood thinner warfarin prevents strokes and saves money, but the drug is only used by a little more than half the elderly patients with abnormal heart rhythms who might benefit from it, a new study has found. An estimated 2.3 million Americans have atrial fibrillation--electrical disturbances in the heart that cause the organ to beat erratically. The abnormal beating can lead to blood clots that block vessels in the brain, causing so-called ischemic strokes. A form of the condition, called non-valvular atrial fibrillation, or NVAF, is particularly dangerous. NVAF accounts for between 15% and 20% of strokes in the United States each year. Warfarin (sold as Coumadin, Jantoven, Marfarin and others) prevents ischemic strokes by keeping clots from forming. The anticoagulant drug is temperamental, though: too much can cause life-threatening bleeding and even strokes resulting from leaking blood vessels, known as hemorrhagic strokes. "Physicians are very concerned in the elderly population about significant bleeding events and may overestimate this risk and underestimate the relative benefit in terms of preventing ischemic stroke and other clot-related complications," said Dr. James V. Freeman, a cardiology fellow at Stanford University who was not involved in the study.

Taken together, the direct costs of treating strokes from atrial fibrillation exceed $2.5 billion a year, the authors write in the journal Stroke. They calculated the healthcare system would save roughly $1.1 billion of that amount if all patients with atrial fibrillation who are candidates for warfarin received well-controlled treatment with the drug. The study was funded by Boehringer Ingelheim GmbH (Ingelheim DEU), which received FDA approval in October for its blood thinner Pradaxa, a potential alternative to warfarin for preventing strokes linked to nonvalvular atrial fibrillation. Unlike warfarin, Pradaxa does not require blood testing and can be taken on a twice-daily regimen.

Doctor Andrew Wakefield, the-now disgraced British doctor who published studies linking vaccines with autism, committed an "elaborate fraud" by faking data, the British Medical Journal said last Wednesday. The journal's editors said it was not possible that Wakefield made a mistake but must have falsified the data for his study, which convinced thousands of parents that vaccines are dangerous and which is blamed for ongoing outbreaks of measles and mumps. The journal supported its position with a series of articles by a journalist who used medical records and interviews to show that Wakefield falsified data. For instance, the reports found that Wakefield, who included data from only 12 children in his report, studied at least 13 and that several showed symptoms of autism before having been vaccinated. Fears that vaccines might cause autism have not only caused parents to skip vaccinating their children, but have forced costly reformulations of many vaccines. "Who perpetrated this fraud? There is no doubt that it was Wakefield," BMJ editor Dr. Fiona Godlee and colleagues wrote in a commentary.

In 1998, The Lancet medical journal, a rival to the BMJ, published a study by Wakefield and colleagues linking the combined measles, mumps and rubella (MMR) vaccine with autism. The other researchers later withdrew their names from the study and The Lancet formally retracted the paper in February. Wakefield denied the allegations. "The study is not a lie. The findings that we have made have been replicated in five countries around the world," Wakefield said. A disciplinary panel of Britain's General Medical Council said last February that Wakefield had presented his research in an "irresponsible and dishonest" way and had brought the medical profession into disrepute. Godlee and colleagues said the work was based not on bad science but on a deliberate fraud. "Clear evidence of falsification of data should now close the door on this damaging vaccine scare," they added.
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Date:Jan 10, 2011
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