28 February 2018
WEDNESDAY, Feb. 28, 2018 (HealthDay News) — Bacteria that commonly live on your skin’s surface just might be protecting you from cancer. Researchers from the University of California, San Diego, said that one particular strain of bacteria appears to help ward off skin cancer by suppressing the spread of tumor cells triggered by over-exposure to the sun’s ultraviolet (UV) rays. The new research, based on studies using mice, was published in the Feb. 28 issue of Science Advances. “Everyone has some strains of this bacterial species,” explained Dr. Richard Gallo, the study’s co-author. “About 20 percent seem to have this particular strain.” Gallo is chairman of the university’s dermatology department. Still, the revelation that it engages in anti-cancer activity “is entirely new,” he said. So could the fresh finding lead to new skin cancer treatments or preventive interventions based on the bacterial resources of people’s own “skin microbiome”? “It is early to say for sure,” Gallo said. “But the hope is that applying this could protect people as well as we have shown it works in mice.” However, experts point out that research conducted in animals frequently doesn’t produce similar results in humans. Many types of bacteria reside harmlessly on the surface of a healthy human body. But the specific bacteria in question — a strain called Staphylococcus epidermidis — appears to produce a specific anti-cancer compound known as 6-N-hydroxyaminopurine (6-HAP), the researchers found. By interfering with normal DNA processes, 6-HAP appears to halt tumor cells in their tracks without causing any harm to the host. In addition, the researchers said, preliminary animal testing suggested that even more may be possible. Injecting 6-HAP directly into the bloodstream may inhibit the onset of cancer or curtail the growth of melanoma tumors by more than 50 percent, they noted. The study team pointed out that, each year, more than one million Americans get a new skin cancer diagnosis. The new study began with the researchers exploring the potential of 6-HAP in a laboratory setting. Cancerous tumor cells were exposed to the compound, resulting in reduced proliferation of some types of cancer, according to their report. Next, the researchers tested the protective potential of intravenously injecting 6-HAP into mice. To check how safe such a procedure would be, the team injected the compound once every 48 hours for two weeks, watching for signs of toxic impact. No toxicity was observed in the mice. Then, one of two types of the staph bacteria were injected into a pool of mice who were exposed to a particularly aggressive form of fast-growing cancer. In all cases, the “density” of the injected bacteria was described as similar to levels typically found on normal human skin. The researchers found that one type of injected staph produced the 6-HAP compound, but the other did not. Mice that had been injected with the bacteria that did not produce 6-HAP experienced rapid tumor growth, which the researchers said they’d expected. But those injected with 6-HAP-producing bacteria saw the number and growth of cancerous tumors fall off “significantly,” the investigators found. Gallo and his colleagues said their findings suggest that this common skin bacteria may help guard against the development of skin cancer. However, they added that more research will be needed to understand exactly how the protective process works, as well as to explore how it might be harnessed to serve as an effective anti-cancer treatment in people. That thought was seconded by Ashani Weeraratna, a professor and co-program leader of immunology, microenvironment and metastasis at the Wistar Institute’s Melanoma Research Center in Philadelphia. “I think a lot of rigorous research is still required,” she said. “It’s clear that an understanding of the microbiome — the bacterial landscape, so to speak — is critical to harness the full potential of some of the outstanding immunotherapy we have available to treat cancers, like melanoma,” Weeraratna said. “Therefore, these findings are very important,” she noted. “If we can understand whether a balance between one species of bacteria is better for a patient than another, we might be able to use low doses of antibiotics to encourage the growth of one bacteria over another,” Weeraratna suggested. However, she added that bacteria tend to have a high mutation rate, and thus a high potential for giving rise to antibiotic resistance. Because of this, future studies seeking to exploit the protective potential of skin bacteria “would have to be attempted with high caution,” Weeraratna warned. More information The U.S. National Institutes of Health has more on the human microbiome.
27 February 2018
TUESDAY, Feb. 27, 2018 (HealthDay News) — Those tangled blue varicose veins that can pop up on your legs as you age may be more than unsightly: New research suggests they might quintuple your risk of dangerous blood clots. Known as deep venous thrombosis (DVT), these clots in the legs can be life-threatening if they travel to the lungs or heart, Taiwanese researchers said. “Varicose veins are not merely a cosmetic or symptomatic concern, because they may be associated with increasing risk of more serious disease,” explained lead researcher Dr. Shyue-Luen Chang, a phlebologist in the department of dermatology at Chang Gung Memorial Hospital in Taoyuan. Varicose veins are a common condition affecting about 23 percent of American adults, the researchers said. “Patients with varicose veins may warrant careful monitoring and early evaluation,” Chang added. Among a group of more than 425,000 people, half of whom had varicose veins, Chang’s team found that the condition was associated with 5.3 times increased risk of deep venous thrombosis. Whether varicose veins cause the clots, or are a real risk for them, however, is not known, Chang said. More research is needed since the study did not prove that varicose veins cause the clots, he said. “Not much is known about varicose veins and the risk for these other diseases,” Chang said. “Elucidating potential associations between varicose veins and health-threatening diseases is important.” The researchers also found a trend for an increased risk of pulmonary embolisms or PE (clots in the lung) or PAD (narrowing of the leg arteries) among those with varicose veins, but they weren’t able to tell if varicose veins were a real risk for these conditions. For the study, Chang and colleagues used data from Taiwan’s National Health Insurance program. Patients were enrolled in the database from 2001 to 2013, and they were followed through 2014. One weakness of the study is that insurance claims data do not include information on patients who don’t seek medical care. Therefore, the findings may apply only to risk among patients with more severe varicose veins who needed medical attention, the researchers explained. One U.S. cardiologist called for more research on the possible connection. “Given the very high prevalence of varicose veins in the general population worldwide, the results of this trial should trigger future studies to further investigate the effect of varicose veins on the inflammation and formation of a blood clot, and to assess the link between the severity of varicose veins and DVT,” said Dr. Maja Zaric. She’s an interventional cardiologist at Lenox Hill Hospital in New York City. The study suggests that varicose veins should be taken more seriously and likely treated more aggressively, she said. “It is prudent to establish which category of patients with varicose veins is at the greatest risk and how aggressive and early the treatment should be to prevent serious complications, given morbidity and mortality associated with both DVT and PE,” Zaric said. The report was published Feb. 27 in the Journal of the American Medical Association. More information Visit the U.S. National Heart, Lung, and Blood Institute for more on varicose veins.
27 February 2018
TUESDAY, Feb. 27, 2018 (HealthDay News) — If you’re unlucky enough to come down with the flu, you can blame your own body for your fever, cough, muscle aches and head-to-toe distress, experts say. Most of influenza’s misery is caused by the human body itself, or more precisely the immune system’s response to the virus. “Many of the things that feel bad are the body’s attempts to get rid of the pathogen that’s causing the mischief,” said Dr. Alan Taege, an infectious disease specialist with the Cleveland Clinic. When your body has prior experience with a flu virus, it already knows how to send the right antibodies out to fight off the bug, Taege said. In those cases, folks might not even notice they’ve had a brush with influenza. But when faced with a new invader, the immune system goes into overdrive. It floods the body with a host of immune system-stimulating biochemicals called cytokines. And that helps to explain why this year’s flu season has been so severe — many Americans haven’t had enough prior exposure to the H3N2 flu strain that’s causing such havoc, doctors say. According to Dr. Gregory Poland, “As a result of fighting off the infection, our body releases an army of chemicals, and those are meant to stimulate the immune system. Think of them as chemicals released into the blood to flog the immune cells of the body to rev up, divide, and attack these viral infidels.” Poland is a vaccine expert with the Mayo Clinic in Rochester, Minn. Cytokines also cause inflammation throughout the body, and that inflammation leads to many of flu’s most wretched symptoms, Poland and Taege said. For instance, muscle, joint and body aches occur due to cytokine-prompted inflammation in the limbs. Inflamed air passages produce mucous, causing a runny nose, coughing and sneezing. Cytokines also cause the body to raise its temperature, resulting in fever. What’s more, the cytokine interferon has been linked to symptoms of headache. It’s also possible that blood vessels in the brain dilate in response to fever, creating a headache by increasing pressure inside your head. Taege likens this inflammation to your skin’s response to a very hot object. You feel pain, and the place that’s been seared will turn red and possibly blister. Over a few days, the burned spot starts to calm down and heal. “The cytokines produce an inflammatory reaction that doesn’t necessarily cause a blister like a thermal burn, but if you look at the throat it can look red. If you look at the airways they can look red,” Taege said. “This is inflammation, and how it interacts with the cells and injures the cells goes on to produce symptoms.” Experiments have shown that people exposed to artificial cytokines will develop symptoms of flu infection, even though the virus isn’t present, Taege said. This is not to say the virus can’t do damage on its own, Poland added. “We recently had a young healthy boy die of influenza,” Poland said. “Autopsy showed the virus had invaded his heart and he died as a result of that.” Flu virus infecting the lungs can directly cause shortness of breath, fever and pneumonia, Poland added. But many deaths caused by flu occur due to a “cytokine storm” — an overwhelming flood of immune chemicals prompted by first exposure to a new and dangerous influenza virus, Poland said. Many of the young and healthy people killed by the flu during the 1918 influenza pandemic are believed to have died due to cytokine storm. “The body is so massively activated in an attempt to fight off this virus that it releases too many of these internal chemicals,” Poland said. That’s why flu shots are recommended. They teach the body how to produce antibodies to fight off the flu without mounting a full-fledged cytokine defense, Taege and Poland explained. With flu activity still elevated across much of the United States, Taege said the vaccine can help limit its damage. “Should you encounter the flu virus, then it can control it much more quickly,” Taege said. People treating flu symptoms most often are treating the inflammation produced by cytokine release. That’s why nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin and ibuprofen (Motrin, Advil) are recommended, Poland said. You should also rest, drink plenty of fluids and continue to eat, Poland said. Flu sufferers who remain active are adding to the body-wide inflammation caused by cytokines, Poland said. And those who stop eating are robbing the body of energy it needs to recover. “One of the effects of this cytokine release is it really revs up your metabolism,” he said. “You actually need more caloric intake to sustain the body.” More information The U.S. Centers for Disease Control and Prevention has more about flu symptoms and complications.
26 February 2018
MONDAY, Feb. 26, 2018 (HealthDay News) — Many breast cancer patients say they’ve heard scary stories about radiation therapy, but their actual experience is usually better, new research finds. The study of more than 300 women who underwent breast radiation found that almost half had heard “frightening” stories going into treatment. But only 2 percent ultimately agreed that the stories were true. And over 80 percent of all patients said their experience with radiation therapy was actually “less scary” than they’d expected. Researchers said the findings show that the public still has misconceptions about “modern” radiation therapy. “The word ‘radiation’ itself sounds frightening, and it’s associated with many negative news stories,” said senior study author Dr. Susan McCloskey. But over the past 20 years, there have been key advances in how breast radiation is given, explained McCloskey, an assistant professor of radiation oncology at the University of California, Los Angeles. It’s more precise and shorter in duration — which has helped limit short-term side effects like skin burning and breast pain. Doctors can also now create individualized radiation plans for each patient, and give the treatment in “more convenient” schedules, McCloskey noted. Dr. Beryl McCormick is a radiation oncologist at Memorial Sloan Kettering Cancer Center in New York City. She said that in her experience, it’s “extremely common” for patients to go into treatment having heard scary stories. The side effects of any cancer treatment will vary from one person to another. But McCormick said it’s possible to predict what women can typically expect. For example, skin symptoms vary based on whether a woman had only the breast tumor removed (a lumpectomy), or breast-removal surgery (a mastectomy). With lumpectomy patients, McCormick said she usually tells them the skin effects will be similar to what would happen if they were out in the sun for two hours without sunscreen. Those skin symptoms typically go away a few weeks after treatment ends, she noted. With mastectomy patients, the effects would typically be more pronounced and lasting, because the radiation therapy is actually, in part, targeting the skin, McCormick said. What’s important, she added, is that women have a thorough discussion of the benefits and risks of radiation therapy when making treatment decisions. “That discussion should start with their surgeon, who is usually the first [doctor] a woman will see,” McCormick said. If a woman finds the surgeon cannot answer all her questions, she can ask to talk to a radiation oncologist, McCormick suggested. The study findings were based on 327 women who’d been treated for breast cancer within the past several years. They’d had surgery, followed by radiation — usually a lumpectomy, though 17 percent had undergone a mastectomy. Overall, 47 percent said that before starting treatment, they’d read or heard “scary” stories about the effects of breast radiation. And many went into treatment worried about risks like skin burning and damage to the internal organs. In hindsight, though, few women felt their experience matched the stories they’d heard. Instead, 84 percent said their side effects — including skin symptoms, pain and fatigue — had been less serious than they’d expected. Similar percentages also said their treatment had been less disruptive to their work and family life than they’d feared. The long-term outlook was better than most women had thought, too. Of women who’d gotten a lumpectomy, 89 percent said the appearance of their irradiated breast was better than they’d expected. Similarly, 67 percent of mastectomy patients said the appearance of the radiation-treated area was better than they’d anticipated, according to the report. Finally, the vast majority of women agreed with the statement, “If future patients knew the real truth about radiation therapy, they would be less scared about treatment.” The study was published Feb. 26 in the journal Cancer. McCloskey said she hopes the findings will offer future patients a “better idea of the breast radiation experience when making treatment decisions.” McCormick agreed. “Almost everyone in the study went through [radiation] therapy and said it wasn’t as scary as they’d thought,” she said. “I think that’s pretty powerful.” In the longer term, chest radiation carries a risk of heart or lung disease, since it can damage those organs. But recent research shows that among nonsmoking women who receive breast radiation, less than 1 percent ultimately die of heart disease or lung cancer, according to McCloskey’s team. More information The U.S. National Cancer Institute has more on radiation therapy.
25 February 2018
SUNDAY, Feb. 25, 2018 (HealthDay News) — Guys, a perfect shave may be more about preparation and technique than the actual razor. “The perfect shave is a combination of art and trial and error,” said Dr. Robert Anolik, a clinical assistant professor of dermatology at the New York University School of Medicine. “That said, there are steps you can take to help ensure a clean and comfortable shave,” he said in an American Academy of Dermatology news release. First, wet your skin and hair to soften it. An ideal time to shave is immediately after a shower. Your skin will be warm, moist and free of excess oil and dead skin cells that can clog up your razor blade, Anolik said. Use a foaming shaving cream. If your skin is very dry or easily irritated, choose one that’s meant for sensitive skin. “Using a circular motion, apply a small amount of the cream to your face using your fingers or a shave brush. A shave brush can help by lifting the hairs and more evenly coating them with the shaving cream,” Anolik said. Let the cream sit for two to three minutes, and then start shaving in the direction that your facial hair grows. This will help prevent razor bumps and burns. Rinse after each swipe of the razor. Change your razor blade or throw away disposable razors after five to seven shaves, Anolik advised. After you finish shaving, rinse your face with cold water to ease inflammation. Then apply a moisturizer with an SPF of 30 or higher. Between shaves, make sure your razor dries completely to prevent growth of bacteria. Store it in a dry location. “If you’re using the right technique but still experiencing razor bumps, razor burns or ingrown hairs, consider switching razors,” said Anolik. “For some men, multi-blade razors can work too well, or shave too closely to their skin. Try using a single- or two-blade razor instead and do not stretch your skin taut while shaving,” he suggested. More information The American Academy of Dermatology has more on men’s skin care.
23 February 2018
FRIDAY, Feb. 23, 2018 (HealthDay News) — The health risks are high for young people who use tanning beds, but not all parents seem to see it that way. To figure out why that is, researchers polled more than 1,200 parents of U.S. kids aged 11 to 17 years. The investigators found that parents who are less likely to believe that indoor tanning is harmful for teens include: Fathers. Parents who’d used indoor tanning devices themselves. Parents who never received skin cancer prevention counseling from their child’s doctor. Parents of boys. Parents of older teens (aged 16 to 17). Parents of teens whose skin was less reactive to the sun. “Parents who have never seen their children get sunburned or discussed skin cancer prevention with a doctor may not be aware of the dangers of unprotected exposure to ultraviolet light,” study author Dr. Maryam Asgari said in a news release from the American Academy of Dermatology (AAD). “Since mothers are often the ones to take their children to the doctor, fathers may be less likely to receive skin cancer prevention counseling from their child’s provider,” Asgari said. She’s a dermatologist and associate professor at Harvard Medical School and Massachusetts General Hospital. It’s not surprising that parents might not object to their kids’ tanning if they’ve tanned indoors themselves, Asgari said. But, “it’s important for all parents to understand the dangers of tanning at a young age and communicate those dangers to their children,” she added. “If you avoid tanning beds, especially when you’re young, you can reduce your risk of skin cancer and early skin aging in the future,” Asgari explained. Using indoor tanning beds before age 35 increases the risk for melanoma — the deadliest type of skin cancer — by 59 percent, and the risk rises with continued use, according to the AAD. A 2017 study found that 45 percent of people who start tanning before age 16 do so with a family member. Results of the new study were scheduled for presentation Friday at the annual meeting of the American Academy of Dermatology, in San Diego. Research presented at meetings should be considered preliminary until published in a peer-reviewed medical journal. More information The U.S. Centers for Disease Control and Prevention has more on the dangers of indoor tanning.
23 February 2018
FRIDAY, Feb. 23, 2018 (HealthDay News) — The antibiotic clarithromycin (brand name: Biaxin) may increase the long-term risk of heart problems and death in patients with heart disease, according to U.S. health officials. As a result, the federal Food and Drug Administration said Thursday that it’s recommending that doctors carefully weigh the benefits and risks of the drug before prescribing it to patients with heart problems. The agency said its warning is based on a 10-year follow-up study of patients with coronary heart disease. The study found an unexpected and unexplained increase in deaths among heart disease patients who took clarithromycin for two weeks and were followed for one year or longer. There’s no clear explanation for how clarithromycin would increase heart disease patients’ risk of death, the FDA said in a news release. One heart specialist said this type of alert is worth heeding, however. “It is important for health professionals and pharmacists to identify potential interactions between medications and eliminate prescription errors to prevent this risk,” said Dr. Marcin Kowalski. He directs cardiac electrophysiology at Staten Island University Hospital in New York City. The FDA said it has added a new warning about this increased risk for heart patients, and is advising doctors to consider prescribing other antibiotics to these patients. The agency added that it will continue to monitor safety reports in patients taking clarithromycin. The antibiotic is used to treat many types of infections affecting the skin, ears, sinuses, lungs and other parts of the body. Doctors should talk to their heart patients about the risks and benefits of clarithromycin and alternative treatments. If doctors prescribe clarithromycin to patients with heart disease, they should inform those patients about the signs and symptoms of cardiovascular problems, the FDA said. And patients with heart disease should tell their doctor about their condition, especially when they are being prescribed an antibiotic to treat an infection. Heart disease patients should not stop taking their heart disease medicine or antibiotic without first talking to their doctor, the FDA said. Patients taking the antibiotic should seek immediate medical attention if they experience symptoms of a heart attack or stroke, such as chest pain, shortness of breath or trouble breathing, pain or weakness in one part or side of the body, or slurred speech, the agency said. Dr. Satjit Bhusri is a cardiologist at Lenox Hill Hospital in New York City. He said, “Although this study suggests an association between this specific antibiotic, there have not been any direct correlations to increased heart disease. “I would also extend this to all antibiotics in general. A short course of antibiotic therapy for a bacterial infection should be initiated if indicated by the physician; and a history of antibiotic therapy, at this time, should not be considered a risk factor for heart disease,” he said. More information The U.S. National Library of Medicine has more on clarithromycin.
15 February 2018
THURSDAY, Feb. 15, 2018 (HealthDay News) — Everyday products such as perfume, skin lotion, hair spray, deodorant, household cleaners and lawn pesticides are a top source of air pollution, as damaging to air quality as the exhaust from cars and trucks, a new report shows. Consumer products containing compounds refined from petroleum all release small amounts of smog-producing particles into the air, the researchers explained. Combined, these products now release as many volatile organic compounds (VOCs) into the atmosphere as vehicle emissions do. “The use of these products emits VOCs in a magnitude that’s comparable to what comes out of the tailpipe of your car,” said study lead author Brian McDonald. He’s a researcher with the University of Colorado working in the U.S. National Oceanic and Atmospheric Administration’s (NOAA) Chemical Sciences Division. Volatile organic compounds transform into smog-producing ozone when they react to nitrogen oxides in the air and the sun’s heat, according to the Environmental Protection Agency. Consumer products are designed to release VOCs into the air, noted study team member Jessica Gilman, a research chemist with the NOAA’s Chemical Sciences Division. “Many of the volatile chemical products we use every day are intended to simply evaporate,” Gilman said. “Think of using hand sanitizer in cold and flu season, scented products, or the time spent waiting for paint, ink and glue to dry. In all of these instances, we are waiting for these volatile chemical products to evaporate.” In the report, a fresh assessment of air quality in Los Angeles using sophisticated new equipment determined that the amount of VOCs emitted by consumer and industrial products is actually two to three times greater than what had been previously estimated. This finding could be surprising to some, given that people use about 15 times more fuel by weight than they do consumer products containing petroleum-based compounds, researchers said. But as regulators have clamped down on transportation pollution — requiring more efficient cars and more tightly sealed gas pumps — consumer products have become a more prominent source of volatile organic compounds, the researchers explained. “In a way, this is a ‘good news’ story,” McDonald said. “As we control some of the biggest [pollution] sources in the past, other sources are emerging in relative importance, such as the use of these everyday chemical products.” Researchers first looked at the hydrocarbons in the Los Angeles air, which are the chief VOCs associated with diesel and gasoline, Gilman said. “The ambient levels of these hydrocarbons have decreased by a factor of 50 over the last 50 years. That’s really surprising, since diesel and gasoline fuel use has actually tripled during that time,” Gilman said. But the study team also found that levels of other less commonly measured VOC gases, such as ethanol and acetone, were both higher than expected and had been increasing during the same period of time, Gilman said. That led researchers to start looking for the unique chemical fingerprints of solvents and compounds used in consumer products, Gilman said. Previous EPA estimates held that about 75 percent of VOC emissions came from vehicle sources and about 25 percent from chemical products. The new study puts the split closer to 50-50, showing that “everyday consumer choices can have a meaningful impact on urban air quality,” said research team member Christopher Cappa, a professor of civil and environmental engineering at the University of California, Davis. “We can confidently say that emissions of these nontraditional sources will negatively impact urban air quality pretty much anywhere they are used in large quantities — that is, pretty much any city around the U.S., Europe or the world,” Cappa said. The findings were published Feb. 16 in the journal Science. Based on these findings, air quality models “must be adapted to capture the changing pattern of emissions,” Alastair Lewis, a professor of atmospheric chemistry at the University of York in England, wrote in an accompanying editorial. Unfortunately, petroleum-derived compounds are in nearly all products one might find under their kitchen sink or in their garage, Gilman said. Further research is needed to figure out exactly which VOCs are more active in smog formation, so they can be taken out of circulation, Cappa and McDonald said. In the meantime, consumers and industries can help by using as little product as they can to get whatever job done, McDonald said. They can also choose unscented products. More information The California Air Resources Board has more about consumer products and air pollution.
15 February 2018
THURSDAY, Feb. 15, 2018 (HealthDay News) — In what researchers call a first step toward personalized vaccines for a multitude of cancers, a vaccine made from stem cells protected mice from tumors. The vaccine was composed of induced pluripotent stem cells (iPS cells) — which are adult cells that have been reverted back into stem cells. They are similar to the primitive cells found in embryos, and they have the potential to develop into any type of body tissue. Researchers have been studying iPS cells as a way to treat various diseases. The general idea is to take cells from an adult patient — from the skin, for instance — then genetically tweak them so they “rewind” into iPS cells. Those cells could then be used to generate healthy replacement tissues for those damaged by disease or injury. But it turns out that iPS cells also have similarities to tumor cells, explained senior researcher Dr. Joseph Wu, a professor at Stanford University School of Medicine. Specifically, both iPS cells and cancer cells share various antigens — or proteins — on their surfaces. So, Wu and his colleagues decided to see if iPS cells could serve as a vaccine against cancer: If the immune system is exposed to the cells, would it be primed to recognize and attack any tumor cells that later arise? They found that, at least in lab mice, the concept worked. “This is obviously just a first step,” stressed Dr. Nigel Kooreman, who also worked on the study. No one knows if the premise will pan out in humans. The next step will be to test the approach in human cells in the lab dish, according to Kooreman, who was a postdoctoral scholar at Stanford at the time of the study. The results, published Feb. 15 in the journal Cell Stem Cell, come on the heels of another cancer vaccine study conducted by some of the same researchers. In that trial, a shot of two compounds stimulated the immune system to seek and destroy several different kinds of cancer cells — again, in mice. The hope with the latest research, Kooreman said, is to eventually create personalized vaccines from an individual’s own iPS cells that could protect against a range of cancers. “I think this is a really exciting study,” said Dr. Sasha Stanton, of the University of Washington’s Cancer Vaccine Institute in Seattle. There are, of course, many unanswered questions, according to Stanton, who was not involved in the research. Any vaccine used for cancer prevention would have to be “very, very safe,” she pointed out. With iPS cells, Stanton explained, there is always some concern that they could develop into tumors. Beyond that, she said, there will be questions about how long would any immune response from vaccination would last. Would it protect people from cancer for 20 years, or would repeat “boosters” be needed, Stanton wondered. But these initial findings are promising, Stanton said. For the study, Wu’s team used four groups of mice: In one, the animals were injected with a control solution; another received an immune-boosting substance called an adjuvant; a third group received injections of iPS cells that were genetically matched to each animal; the fourth received iPS cells plus the adjuvant. All of the animals were later implanted with mouse breast cancer cells. While those tumors grew in most of the animals, the picture was different for mice that received iPS cells plus the adjuvant: Breast tumors shrunk in 7 of the 10 animals, and two completely rejected the cancer, the researchers said. Similar results were seen when mouse versions of melanoma and mesothelioma (a type of lung cancer) were studied. What happens to the iPS cells after they are injected into the body? The immune system destroys them, Kooreman said. And before the iPS cells were infused into the animals, they were treated with radiation. That, Kooreman explained, was to prevent them from developing into tumors. Another safety concern is that iPS cells could trigger an immune response against the body’s healthy tissue. But there were no signs of that in the lab mice, according to Kooreman. “So far, in our preclinical studies of mice, it appears safe,” he said. If a preventive cancer vaccine can be developed for humans, how would it be used? At first, Stanton said, it could be used to prevent recurrences in patients successfully treated for cancer. Kooreman added an iPS cell vaccine could also potentially aid cancer treatment. He envisioned it working this way: After a patient receives an initial cancer therapy, the vaccine could be used to “reactivate the immune system to attack any remnant cancer cells.” More information The U.S. National Cancer Institute has an overview on cancer vaccines.