HPV tied to throat cancers: study

NEW YORK (Reuters Health) - A sexually transmitted infection usually thought of in connection to cervical cancer is also tied to a five times greater risk of cancer of the vocal chords or voice box, a new report suggests.
Combining the results of 55 studies from the past two decades, Chinese researchers found 28 percent of people with laryngeal cancers had cancerous tissue that tested positive for human papillomavirus (HPV).
But that rate varied widely by study, from no throat cancer patients with HPV to 79 percent with the infection.
"We're finding that HPV appears to be linked to a number of squamous cell carcinomas of the head, neck and throat," said Dr. William Mendenhall, a radiation oncologist from the University of Florida in Gainesville who didn't participate in the analysis.
However, he told Reuters Health, "I think the risk of HPV on laryngeal cancer is probably relatively low. Most of the patients we see currently that come in with laryngeal cancer have a strong history of cigarette smoking, also heavy drinking."
Along with tobacco and alcohol, having a poor diet and exposure to certain chemicals can increase a person's risk of laryngeal and other head and neck cancers.
The American Cancer Society estimates 12,360 people will be diagnosed with laryngeal cancer in the United States in 2012 and that there will be 3,650 deaths from the disease.
Along with their larger review, researchers led by Dr. Xiangwei Li, from the Chinese Academy of Medical Sciences and Peking University Medical College in Beijing, analyzed 12 studies that compared cancerous and non-cancerous tissues from a total of 638 patients. They found the cancerous throat tissue had 5.4 times the odds of testing positive for HPV infection, compared to non-cancerous tissue.
The analysis was published last week in the Journal of Infectious Diseases.
Mendenhall said that of all head and neck cancers, HPV seems to play the biggest role not in laryngeal cancer, but in cancer of the tonsils and back of the tongue.
However, he added, "the exposure is probably decades earlier. Someone who develops a base of tongue cancer when they're 50, they probably were exposed to the virus years before, in their teens or 20s."
At least half of sexually-active people get HPV at some point in their lives, according to the Centers for Disease Control and Prevention (CDC), but the virus is usually cleared by the immune system. Only some of the 40-plus HPV strains have been tied to cancer.
Based on the current findings, it's difficult to know how many of the laryngeal cancers in the original studies were actually caused by the virus, researchers said.
But Mendenhall said extending HPV vaccination to boys and young men, as the CDC has recommended, "will hopefully reduce at least some of these HPV-related cancers."

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Uncircumcised boys and men may face more UTIs

NEW YORK (Reuters Health) - Infections of the kidney, bladder and urethra happen in uncircumcised baby boys at ten times the rate of circumcised boys, and over a lifetime uncircumcised men are four times more likely to experience one, according to a new analysis of past research.
Urinary tract infections (UTIs) are most common in boys' first year of life, and circumcision was already known to make a difference in their risk, but how much and whether that carried through to adulthood was unclear, Australian researchers say.
They found that circumcision "provides considerable protection and over the lifespan makes about a three- to four-fold difference by our prediction, which is quite striking in public health terms," lead study author Brian Morris, professor of molecular medical science at the Sydney Medical School, University of Sydney, told Reuters Health.
Morris and a colleague examined 22 studies published between 1987 and 2012 that included a total of 407,902 males across the globe, a quarter of whom were uncircumcised.
Breaking down the results by age, they calculated that the likelihood of a UTI between birth and one year of age is 9.9 times higher in uncircumcised boys compared to circumcised boys. Between ages 1 and 16, uncircumcised boys are at 6.6 times higher risk, and after age 16 their risk is 3.4 times that of uncircumcised men.
Based on those findings, the researchers projected that doctors could prevent one UTI with every four circumcisions, "which is astronomical," Morris said.
The younger the infant, the more serious a UTI can be, the researchers note in their report, which is published in the Journal of Urology. Side effects of a UTI in infants can include kidney scarring, fever, pain and blood infections.
Health experts have mostly framed circumcision as a public health preventive measure focused on HIV and other sexually transmitted diseases.
In August, the American Academy of Pediatrics for the first time stated that the health benefits of circumcision outweigh the risks, but added that the decision to circumcise a child remains with parents.
The U.S. Centers for Disease Control and Prevention is currently evaluating the potential health impact of circumcision, according to a spokeswoman, but any recommendations that come of that will also be voluntary, she said.
The estimated health benefit Morris and his colleague found was several times larger than what was projected in two previous studies, which suggested 111 or 195 circumcisions would be needed to prevent one case of UTI in the first year of life.
One expert questioned the new findings based on the methods Morris' team used.
Zbys Fedorowicz, director of the Bahrain branch of the UK Cochrane Centre, a non-profit organization that evaluates medical studies, said that the 22-study analysis combined different types of studies and the researchers failed to assess their quality.
"It doesn't mean to say that these guys are necessarily wrong, it's just that we don't know because the methodological approach that they used isn't thorough enough, it's not transparent, it's not reproducible and it's not clear," Fedorowicz said.
In November, Fedorowicz and colleagues published a report concluding that no existing study that examined the risk of urinary tract infections and circumcision was of high enough quality for any recommendation.
Dr. Robert Van Howe, clinical professor of pediatrics at the Michigan State University College of Human Medicine and vocal critic of circumcision, also found the new study problematic.
Van Howe said that diagnostic criteria for urinary tract infections differ between researchers and that the cost/ benefit analysis of circumcision as a preventive tool for infections doesn't add up.
At $200 each circumcision, preventing one urinary tract infection would cost $40,000, "which you can treat with an $18 antibiotic; it's overkill," Van Howe said.
"You would think we have long lists for dialysis in men because they're not circumcised, but it just isn't a problem, it's fear mongering," Van Howe told Reuters Health.
A middle ground might be to let boys decide for themselves at age 14 or 16 to become circumcised, Van Howe suggested. "You can leave this choice up to the person who has to live with the consequences," Van Howe said.
Morris maintains that the study sends "a really strong signal for advocacy of circumcision as a public health intervention in reducing these various - and in many cases very serious - conditions over the lifetime.

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In Search of a Better Condom

It's hard to believe, but the condom is still the only way to protect against pregnancy and HIV at the same time. But researchers say they believe they can develop a kind of 21st-century contraceptive that offers superior protection against pregnancy and sexually transmitted diseases and that people will like enough to use consistently.
A paper describing early work on the project was published earlier this month in the journal PLoS One. The research team, led by Kim Woodrow at the University of Washington, received a grant of nearly $1 million last month from the Bill & Melinda Gates Foundation to pursue the research.
The product is an electrically spun cloth with nanometer-sized fibers that can dissolve to release drugs, such as medications that prevent pregnancy and HIV infection. The drug-eluting fibers represent "multipurpose prevention technology," a method that simultaneously prevents sexually transmitted infections and unintended pregnancy through a combined physical and chemical barrier.
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"Condoms and vaginal rings and IUDs have been around for a very long time," Cameron Ball, a co-author of the paper and graduate student in bioengineering, told TakePart. "People would like more options. No one option will be the silver bullet. The idea is to have multiple options that people can choose for their lifestyle."
Improved methods to protect against STDs and pregnancy are needed in both developing and developed countries. The spermacide nonoxynol-9 is highly effective at pregnancy prevention but promotes vaginal inflammation, which then increases the risk of STD transmission.
"What we're hoping to provide is a method of drug delivery that could be used with a variety of drug compounds," Ball says. "There are multiple products in the development pipeline to address this need. These are largely vaginal rings, but vaginal rings are limited in what they are able to deliver. They deliver compounds that are less water soluble. Using fibers allows you to work with multiple drugs with different properties. You can have combinations of pharmaceutical agents that you couldn't necessarily have with a vaginal ring or with a condom."
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During electrospinning, an electric field is used to launch a charged fluid jet through the air to create extremely delicate nanometer-scale fibers that stick to a collection plate. (One nanometer is about one 25-millionth of an inch.) The stretchy fibers are the platform for delivering medications in the same way that drugs are delivered through pills or gels. The fibers can also carry larger molecules, such as proteins and antibodies, that are hard to deliver through other methods. So far, the team has created a fabric that serves as a physical barrier to block sperm or to release drugs, such as contraceptives and antiviral medications.
The fabric dissolves within minutes, which is considered a benefit because it offers immediate and discreet protection. But the approach also allows for controlled release of multiple compounds, Ball says. Last year, a study aimed at preventing heterosexual HIV transmission using a gel with the drug tenofovir failed—the likely result of the drug's strength fading by the time of sex.
"If you can have a longer-lasting gel with nanoparticles, that would be beneficial," Ball says. "We're trying to fill a niche in terms of product lifespan."
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The cloth could be inserted directly into the body or used as a coating on vaginal rings or other products, Ball says. While the primary goal of the research is for products that can be used in places like Africa, where HIV transmission is especially high,  the technology could appeal to a wide range of societies and cultures.
"You could have fibers that stay in place for longer or be shaped in the shape of a diaphragm," he says. "You could include herpes medication. Herpes prevention is somewhat controversial—it's not clear whether taking herpes medications prophylactically will help prevent the spread of the virus. That is another application, potentially.

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