What’s the News: Scientists have developed a new carbon nanotube device (pictured above) that’s capable of detecting single cancer cells. Once implemented in hospitals, this microfluidic device could let doctors more efficiently detect the spread of cancer, especially in developing countries that don’t have the money for more sophisticated diagnostic equipment. Any improvement in detecting cancer’s spread is important, says MIT associate professor of aeronautics and astronautics Brian Wardle, because “of all deaths from cancer, 90 percent are … from tumors that spread from the original site.”
What’s the Context:
Not So Fast: The process of commercializing a technology like this takes quite a while; the previous version from four years ago is being tested in hospitals now and is may be commercially available “within the next few years.”
Next Up: The scientists are currently tweaking the device to try to catch HIV.
Reference: Grace D. Chen et al. “Nanoporous Elements in Microfluidics for Multiscale Manipulation of Bioparticles.” Small. DOI: 10.1002/smll.201002076
Image: Brian Wardle/MIT
What’s the News: Scientists have identified three gene mutations that lead to acute myeloid leukemia, a cancer that afflicts white blood cells, which may lead to better cancer drugs in the future. As Wellcome Trust Sanger Institute hematologist George Vassiliou told the BBC, his team’s study “found critical steps that take place when the cancer develops. Identifying the biological steps … means we can look for new drugs to reverse the process.”
How the Heck:
What’s the Context:
Not So Fast: Researchers caution that it could take decades before new cancer-fighting drugs based on this study come on the market. This present study only used mice as subjects.
Reference: George S Vassiliou et al. “Mutant nucleophosmin and cooperating pathways drive leukemia initiation and progression in mice.” Nature Genetics. doi:10.1038/ng.796
Image: Wikimedia Commons / Bruce Wetzel
They’re about three and a half feet tall and their origins are mysterious, but an isolated group of Ecuadorians with a genetic mutation causing dwarfism are making news for another reason: They hardly ever get cancer or diabetes. Medical researchers say the villagers’ genetic protection from these diseases could lead to preventative treatments for the general population–and could therefore increase human longevity.
The villagers’ condition is called Laron syndrome, which is caused by an insensitivity to growth hormone.
Laron syndrome results from a mutation in the gene that codes for growth hormone receptor (GHR), a protein that binds with the human growth hormone and ultimately results in the production of the insulin-like growth factor 1 (IGF1), causing cells to grow and divide. When a person has two of these mutated and non-working genes, they can develop the disease. [LiveScience]
Jaime Guevara-Aguirre, the leader of the study about the Ecuadorians appearing in Science Translational Medicine, has been looking into their condition and extraordinary resistance to age-related diseases for more than two decades, since his serendipitous discovery of the people while riding horseback in Ecuador.
“I discovered the population in 1987,” Dr. Guevara-Aguirre said in an interview from Ecuador. “In 1994, I noticed these patients were not having cancer, compared with their relatives. People told me they are too few people to make any assumption. People said, ‘You have to wait 10 years,’ so I waited. No one believed me until I got to Valter Longo in 2005.” [The New York Times]
The study, published in the Proceedings of the National Academy of Sciences, focuses on basal cell carcinoma, a variety of skin cancer associated with hair follicle cells. Basal cell carcinoma is the most common type of skin cancer, and while it rarely metastasizes or kills it’s still considered malignant.
Biochemists Sunny Wong and Jeremy Reiter, from the University of California, San Francisco, wanted to see how tumors develop from cancerous mutations. To do that, they genetically modified mice so that their hair follicle stem cells expressed the human basal cell carcinoma gene. After giving some of the mice a small cut, and leaving others alone, they discovered that tumors only formed on the hurt mice.
When skin is cut, hair-follicle stem cells migrate to the injury. Wong says pre-cancerous cells can lie dormant in the body until a trigger, such as radiation or a build up of mutations, pushes them into forming a tumour. “In this case, wounding got cancerous cells out of their resting phase,” he says. [New Scientist]
For a century, one of the standard procedures for treating women with breast cancer has been the painful removal of the lymph nodes from under the arm, with the belief that this would hamper the cancer’s ability to spread, and extend patients’ lives. A study out in the Journal of the American Medical Association, however, is turning heads by suggesting that—in some cases—this common wisdom be overturned.
For women who meet certain criteria — about 20 percent of patients, or 40,000 women a year in the United States — taking out cancerous nodes has no advantage. It does not change the treatment plan, improve survival or make the cancer less likely to recur. And it can cause complications like infection and lymphedema, a chronic swelling in the arm that ranges from mild to disabling. [The New York Times]
The “20 percent of patients” are those who fit the same criteria as the breast cancer patients in this study: women with early-stage tumors and no noticeable swelling of the lymph nodes, and whose cancer hadn’t spread. All 891 women in the study had a lumpectomy, meaning not all but part of the breast was removed to get the tumor. Of the 891 women, 445 had their lymph nodes removed while 446 didn’t.
[The researchers] found no significant difference in the patients’ chances of surviving five years after their diagnosis. The five-year “disease-free” survival rate was 83.9 percent in those who did not have the more aggressive surgery compared with 82.2 in those who did, the researchers reported. [Washington Post]
The overall survival rate was 91.8% for women who had nodes removed and 92.5% for those who didn’t—again, not a statistically significant difference.
The latest diagnostic tool for oncology comes on four paws and is defined by its very effective nose. In a small study, Japanese researchers found that a dog could detect cases of colorectal cancer by sniffing patients’ breath or stool samples. Previous experiments have shown that dogs can sniff out cases of skin, lung, bladder, and breast cancers; researchers think the tumors give off chemical signals that the dog can detect in bodily substances.
The cancer expert in this case was an eight-year-old black Labrador named Marine who was trained to search for disease traces at the St. Sugar Cancer Sniffing Dog Training Center in Chiba, Japan. She must have been a good student. The research, published in the journal Gut, showed that she had a high success rate:
The Labrador retriever was at least 95 percent as accurate as colonoscopy when smelling breath samples, and 98 percent correct with stool samples, according to the study…. The dog’s sense of smell was especially effective in early-stage cancer, and could discern polyps from malignancies, which colonoscopy can’t. [Bloomberg]
Lead researcher Hideto Sonoda says it would be impractical to use dogs for routine bowel cancer screenings, but adds that further research into dogs’ diagnostic ability could lead to the development of an electronic nose.
Dr Sonoda told the BBC: “The specific cancer scent indeed exists, but the chemical compounds are not clear. Only the dog knows the true answer. It is therefore necessary to identify the cancer specific volatile organic compounds [smells] detected by dogs and to develop an early cancer detection sensor that can be substituted for canine scent judgement. To complete the sensor useful in clinical practice as a new diagnostic method is still expected to take some time.” [BBC]
80beats: In Controversial Scent Lineups, a Dog’s Nose Picks Out the Perp
80beats: New Research Points Toward Artificial Nose Based on Human Smell Sensors
80beats: Sniffing Out Sickness: Mouse Noses Respond to the Urine of Diseased Mice
DISCOVER: Lassie–Get the Oncologist!
DISCOVER: 20 Things You Didn’t Know About… Dogs
Image: flickr / pmarkham
Already, researchers have imagined and built ways to detect one-in-a-billion cancer cells in a person’s bloodstream in order to catch cancer in the act of spreading. Now, that technology is a little closer to moving out of the lab.
Mehmet Toner and colleagues from Massachusetts General Hospital, the brains behind the tech, announced an agreement with a subsidiary of Johnson & Johnson to begin commercial development of their “liquid biopsy.”
The microchip is dotted with tens of thousands of tiny posts covered with antibodies designed to stick to tumor cells. As blood passes over the chip, tumor cells separate from the pack and adhere to the posts. Scientists are wagering that this type of test, if successful, might also detect cancer early in its course, predict the odds for a recurrence, and assess a patient’s general prognosis. [Healthday News]
Toner’s team developed the prototype of the test back in 2007, and for the last several years have refined the extreme sensitivity needed to catch stray cancer cells roaming the bloodstream.