Sometimes, even a tiny cut can have serious and unexpected consequences. New research reveals that even a minor flesh wound can cause previously dormant cancer cells to develop into tumors.

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]

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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.

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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]

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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.

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Smoke is in the air again. Well, smoking, rather. The newest report by the Surgeon General (yes, they’re still doing those) came out this week, and the 30th installment of this institutional dispatch ratcheted up the message. It’s not just a lot of smoking that will kill you; the Surgeon General’s office is now pushing the idea that even one cigarette is one too many—serious damage can start immediately, says the report.

Thursday’s report says there’s no doubt that tobacco smoke begins poisoning immediately — as more than 7,000 chemicals in each puff rapidly spread through the body to cause cellular damage in nearly every organ. “That one puff on that cigarette could be the one that causes your heart attack,” said Surgeon General Regina Benjamin. [AP]

It’s not exactly a revelation that smoking is risky and get riskier the more you do it. However, this is the first in the long line of these reports to really press the points that have turned up in recent research, like epigenetic changes or immediate risk to the cardiovascular system.

The root of the problem is that even small amounts of the chemicals in cigarette smoke cause rapid inflammation in the endothelium, or lining, of blood vessels and in the lungs. Inflammation is increasingly blamed by researchers as a key promoter of blood vessel plaques and clots and in obstructive lung diseases like emphysema. “The evidence on the mechanisms by which smoking causes disease indicates that there is no risk-free level of exposure to tobacco smoke,” the report concludes. [WebMD Health News]

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Is plain old aspirin the best medicine to ward off cancer? A new study in The Lancet says that it could definitely help, but researchers urge caution before anybody goes on a low-dose aspirin regimen for this reason.

The study, led by Oxford’s Peter Rothwell, is actually a review of eight previous studies that compared people on regular doses of low-dose aspirin to those on a placebo. The researchers who initially performed the studies were investigating questions like whether the aspirin regimen was effective in lowering the risk of heart disease. But in doing so, they kept detailed records on the more than 25,000 people who were involved in the studies—including their causes of death.

Deaths from esophageal cancer were reduced by 60% in the aspirin-takers (who took the drug for at least five years), compared with the placebo group. Lung cancer deaths were reduced by 30%, colorectal cancer deaths were cut by 40% and prostate cancer deaths were lowered by 10%, compared with the patients who got placebo. What’s more, the longer people took aspirin, the greater their reduction in cancer risk. [TIME]

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After two years of work developing new guidelines to tell us how much vitamin D and calcium is enough, the Institute of Medicine released its report this week with the basic message: Relax, you’re all doing pretty well.

Yet confusion still reigns in headlines about the report, as there are several different facets to the new standards (and the reaction to them). The new report also seem to contradict earlier, alarming studies that found vitamin D deficiencies in most Americans. So, what’s going on?

Most people are doing just fine

IOM looked at both Vitamin D and calcium intake for different age groups, and slogged through hundreds of studies of the levels of those nutrients versus health. The only group that was found deficient was adolescent girls, whom the researchers said should intake a little bit more calcium.

The panel said its findings challenged the notion that, when it comes to dietary nutrients, “more is better” — a belief that has inspired a multibillion-dollar market for dietary supplements in the United States. Americans spent $1.2 billion last year on calcium supplements and $430 million on pills containing vitamin D, according to the Nutrition Business Journal. [Los Angeles Times]

Ohio State oncologist Steven K. Clinton, a coauthor of the report, says most people have enough variety in their normal diet to get adequate amounts of both nutrients.

New findings? Not convincing enough

The reason that gigantic supplement market exists is that a number of studies have suggested vitamin D—found in some foods but mostly produced in your skin by the action of ultraviolet radiation—could help to prevent diseases like cancer, heart disease, diabetes, and more. But in its meta-review of vitamin D studies, IOM wasn’t convinced. Its report reinforced the traditional wisdom that vitamin D is crucial for skeletal health, but wouldn’t go further in determining healthy levels.

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As the backlash continues against the TSA’s full body scanning and increasingly aggressive pat-downs of those who opt out, the agency has bent a little in one area. The head of TSA today questioned the need to use the added security on pilots. The pilots organization had already told its members to opt out of the scans to avoid extra radiation exposure. Now, the TSA says that as of 2011 pilots will only need to have their airline-issued IDs checked by computer.

“This one seemed to jump out as a common-sense issue,” Transportation Security Administration (TSA) chief John Pistole told Bloomberg News on Friday. “Why don’t we trust pilots who are literally in charge of the aircraft?” That’s exactly the point commercial airline pilots have been making for years. [Christian Science Monitor]

What Pistole did not do, however, was back off the policy of using the scanners on the rest of us. And yesterday on its blog, the TSA tried to launch a PR counter-offensive to the tidal wave of bad press this week. (Though you might not be terribly satisfied with their answer to the question of whether pat-downs are invasive, about which Ars Technica quips, “Nowhere in the “Fact” response does the TSA directly answer the allegation of invasiveness, probably because the pat-downs are invasive.”)

Since the TSA appears disinclined to change its mind about scanning or getting touchy-feely with the general public, lawmakers are beginning to make some noise. In New York, councilman David Greenfield proposed rules to bar TSA from using the x-ray scanners in the city’s airports.

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It’s not like this week was the first appearance of the full-body X-ray scanners in American airports. Yet, thanks to the looming holiday travel season, leaked X-ray images that were supposed to be kept private, and high-profile rebellion by pilots’ organizations and disgruntled passengers, anger is rising against the Transportation Security Administration’s new airport rules. Under the policy, those chosen for extra screening face the dilemma of having their naked bodies revealed to TSA scanners or opting out and having agents feel them up in search of explosives.

But behind the outrage at being asked to surrender even more of our dignity just to get on a plane, there’s another full-body scanning issue simmering: the health dangers of radiation.

How much radiation, and where?

This was the main concern of the Allied Pilots Association. Pilots are already exposed to higher levels of radiation than nearly all professionals because they spend so much time at altitude and receive radiation from space; asking them to take an X-ray every time they get on a plane (even one that the TSA says is thousands of times less intense than a hospital chest X-ray) was asking too much. Popular Mechanics posted more details on pilot exposure.

So what about the rest of us, who fly perhaps only a few times per year? Back in May, professors at the University of California, San Francisco, led by John Sedat sent a letter to the Food and Drug Administration with a litany of red flags about using back-scatter X-ray with such frequency—mostly that the safety has not be independently proven. The FDA finally replied with a lengthy letter citing study after study that show full-body scanning is safe, the agency says.

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The results were so staggering that they stopped the study ahead of schedule to get the word out: A giant study by the National Cancer Institute of more than 50,000 heavy smokers has found a 20 percent reduction in deaths among patients who received a CT scan to catch potential cancer as opposed to a simple X-ray.

“This is huge,” said Dr. Reggie Munden, a University of Texas M.D. Anderson diagnostic radiologist who led the research conducted at the Houston cancer center, one of 33 sites nationally. “It’s a massive ray of hope that we can now offer a scientifically proven test to people at risk of lung cancer and pick up tumors before they’re considered lethal.” [Houston Chronicle]

Participants in the study, which began in 2002, had smoked about a pack a day for at least 30 years (or the equivalent—two packs for 15 years). They received a screening via either CT scan or X-ray three times a year. While the X-ray group lost 442 people to lung cancer, the CT group saw only 354 lung cancer deaths.

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Hallucinogenic drugs are making a comeback–not among the restless youth of today, but among medical researchers. Doctors are increasingly testing illegal drugs like LSD, psychedelic mushrooms, and the party drug ketamine for beneficial effects, and are suggesting that these discredited drugs could have a place in modern medicine. The latest study, published in the Archives of General Psychiatry, found that the active ingredient in hallucinogenic mushrooms helped alleviate depression and anxiety in terminal cancer patients.

“This is a landmark study in many ways,” said Dr. Stephen Ross, clinical director of the Center of Excellence on Addiction at New York University‘s Langone Medical Center, who was not involved in the research. “This is the first time a paper like this has come out in a prestigious psychiatric journal in 40 years.” [Los Angeles Times]

The small pilot study included only a dozen volunteers, so the findings are far from conclusive. The volunteers ranged in age from 36 to 58; all had been diagnosed with advanced-stage cancer and had considerable anxiety as a result of their disease. Each patient had one session in which they were given psilocybin, the active ingredient of magic mushrooms, and another session when they were given a placebo that caused a physiological reaction–still, in most cases the patients could figure out if they’d been dosed or not. In all the sessions the patients were kept under supervision for six hours and were encouraged to lie in the dark while listening to music (no word from the researchers on whether Pink Floyd was provided).

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Girls around the country are starting puberty ever younger, says a new study out in Pediatrics.

Researchers led by Frank Biro studied more than a thousand girls between six and eight years old from New York, Cincinnati, and San Francisco. Their findings: By the age of 7, about 23 percent of black girls, 15 percent of Hispanic girls, and 11 percent of white girls showed enough breast development to be considered pubescent. Those numbers are even more extreme than the findings of a similar 1997 study that seemed to show the age entering puberty was dropping fast.

Says Biro:

“In 1997, people said, ‘That can’t be right; there must be something wrong with the study’. But the average age is going down even further” [Los Angeles Times].

The starkness of Biro’s statistics has drawn plenty of attention. But just what it means is a difficult question, because there’s no “ideal” age for entering puberty.

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When you hear mention of BPA, or bisphenol-A, plastic bottles and food containers likely come to mind. Now, a report presented by activists at the Environmental Working Group says the chemical is also in some paper store receipts.

In the study, which has not been peer reviewed, the environmental group looked for BPA in 36 sales receipts. They found that about forty percent used thermal paper (which has a chemical coating that changes colors when heated) that contained 0.8 to nearly 3 percent pure BPA by weight, 250 to 1,000 times greater than the amount of BPA typically found in a can of food or a can of baby formula. Other research, their report says, shows that BPA can transfer from receipts to a person’s skin, but how much BPA transfers or if it penetrates into the bloodstream remains uncertain. A chemical-industry trade group says the amount transferred is low:

“Available data suggests that BPA is not readily absorbed through the skin,” a spokeswoman from [The American Chemistry Council] said. “Biomonitoring data from the U.S. Centers for Disease Control shows that exposure to BPA from all sources, which would include typical exposure from receipts, is extremely low.”[Washington Post]

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A little stress can do a mouse good, a new cancer study suggests.

Matthew During wanted to see whether stressing out mice by messing with their environment would affect the rate of tumor growth. So, for a study that now appears in Cell, he and his team divided up their mice into two groups. Some mice lived quiet, peaceful lives in cages shared between five mouse roommates, while the other group lived in a stressful cluttered cacophony, where the cages held 18 to 20 animals plus numerous distractions and challenges like toys, mazes, and wheels.

Mice were then injected with tumor cells, which led to malignancies in all of the control animals within 15 days… The rate of tumor formation in animals living in the enriched environment was significantly delayed, and 15 percent had not developed tumors after nearly three weeks; when tumors were visible, they were 43 percent smaller than the lesions on control animals [Scientific American].

Because the “enriched environment” gave those mice so much more to do, an obvious conclusion would be that it’s the uptick in physical activity—not the effect of added stress—that kept tumors at bay. So During’s team tested the mice to see if just giving them more time on the running wheel, independent of the other factors, was enough to see the effect. It wasn’t.

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The latest entry into the cellphones-radiation-health debate is a British study of thousands of children, which investigated whether the proximity of pregnant women to cellphone towers had any effect on whether their kids developed tumors or leukemia. The result: a big no.

Researchers from Imperial College London identified 1,397 children under five who were diagnosed with leukaemia or a tumour of the brain or central nervous system between 1999 and 2001. They compared each child with four children of the same gender who were born on the same day but had not developed cancer [The Guardian].

They then cross-compared all those children to how much radiation their mothers likely received during pregnancy, based on a survey of more than 80,000 cell towers and their radiation output. No matter how they ran the numbers, the team couldn’t find a significant effect.

For instance, the mothers whose children were diagnosed with cancer lived an average of 1,173 yards from a cellphone tower while they were pregnant — statistically indistinguishable from the 1,211 yards that separated the other pregnant women from their nearest cellphone towers. Tallying up the total power output of all cellphone towers within 766 yards of each pregnant woman’s home, they found that both groups had nearly the same exposure — 2.89 kilowatts for the mothers of cancer victims and 3.00 kilowatts for the other mothers [Los Angeles Times].

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