What is HPV-type throat cancer, and how can it be prevented?

Source: www.washingtonpost.com
Author: Lindsey Bever and Marlene Cimons

Tennis great Martina Navratilova has been diagnosed with throat and breast cancer, which she described as a “double whammy” to tennis.com Monday. Calling the illnesses “serious but still fixable,” the 18-time Grand Slam singles winner said she was “hoping for a favorable outcome.”

Navratilova’s Stage 1 throat cancer is related to the human papillomavirus (HPV), the most prevalent sexually transmitted infection in the United States, and the precursor to several cancers.

“HPV-related head and neck cancers are increasing dramatically in the United States,” said Otis Brawley, a professor of oncology at Johns Hopkins University. “The incidence rate has doubled over the last 15 years.”

The majority of patients are men, but “anybody can get it,” he said.

The Washington Post spoke with several health-care experts to answer common questions about HPV and cancer.

What is HPV?
HPV is a group of viruses typically transmitted through skin-to-skin contact, including during sexual activity such as oral, anal or vaginal sex. Most people will contract some form of HPV at some point in their lives, experts said. Some people may never know they have it, and the active infection may be short-lived because, in many cases, the body’s immune system suppresses the virus on its own. But in other cases, the virus can lead to certain forms of cancer, including cervical, anal, vaginal and penile and oral cancers.

Each year in the United States, more than 21,000 women and 14,000 men get HPV-related cancers, according to data from the Centers for Disease Control and Prevention. Cervical cancer is the most common HPV-related cancer among women. Cancers of the back of the throat now account for the largest number of HPV-related cancers, seen mostly in men.

How does HPV cause throat cancer?
HPV causes about 70 percent of oropharyngeal (throat) cancers, including the 30,000 new cases in the United States this year, said Eric Moore, head and neck cancer surgeon at the Mayo Clinic. HPV causes tumors of the tonsil and the back of the tongue predominantly, he said.

HPV strains that cause cancer do so by infecting the back of the throat, causing the cells to undergo a cancerous transition, said Karen Knudsen, chief executive of the American Cancer Society. Knudsen said it is important to remember that not everyone who contracts HPV will develop cancer; the body’s immune system often clears the infection before it progresses to that point. In cases in which the infection persists, it can take years to develop cancer from it, she said.

Is there screening for oral HPV infection?
There is no routine screening for oral HPV infection or cancer, only for cervical cancer, said Shauna Campbell, a radiation oncologist at the Cleveland Clinic. Since HPV can cause cervical cancer, women are routinely tested for the virus during a Pap smear. For those who test positive for HPV, more frequent screenings are offered for cervical cancer. There is also no treatment for HPV infections, Campbell said.

Throat cancers caused by HPV are typically discovered during routine dental or other medical exams, or through self-exams, experts said.

Who is at risk for HPV-related cancers?
“Risks for HPV-related oropharyngeal cancer is five times more common in men than women and appears to be associated most strongly with the number of sexual partners in someone’s life,” said Erich Sturgis, professor and vice-chair of clinical affairs of otolaryngology at Baylor College of Medicine. Heterosexual men are at higher risk than men who have sex with men, while lesbian and bisexual women may be at higher risk than strictly heterosexual women, he said.

People with compromised immune systems or those taking immunosuppressant medications may be at greater risk of not clearing the virus, which may then lead to cancer, experts said.

Age and poor diet may also play a role. For HPV-related oropharyngeal cancers, additional risk factors may include tobacco use and frequent or heavy alcohol consumption. “It’s rare for a risk factor to sit in isolation,” Knudsen said. “If someone has multiple risk factors, we would hypothesize that this person may be at even higher risk” of developing an HPV-related cancer, she said.

What are the symptoms?
The HPV infection is asymptomatic, Campbell said, but symptoms of cancer can vary widely depending on the location. It is common for a person to develop a painless enlarged lymph node in the neck as the first symptom of oropharyngeal cancers, she said. Navratilova told tennis.com that she noticed an enlarged lymph node in her neck, and when it did not go way, she sought medical attention. A biopsy revealed Stage 1 throat cancer, she said.

Occasionally, people will note “a sore throat or trouble swallowing or ear pain or bleeding, but usually the cancer in the tonsil or base of tongue (lingual tonsil) is relatively silent and often missed even when seeing a doctor,” Sturgis said.

If you have an abnormal lump in the neck for more than two to three weeks, a sore throat or tongue, or trouble swallowing for longer than four weeks, you should see an ear, nose and throat doctor, Moore said.

Sores may be a sign to look for with HPV-related cancers in the genital region, experts said.

In general, people should keep in mind that “any change in your health in any of the areas that can be infected by HPV would warrant a trip to your family doctor to determine what’s going on,” Knudsen said.

What is the prognosis for HPV-related cancers
In terms of prognosis, “every cancer is a completely different disease,” Knudsen said.

When HPV-related oropharyngeal cancers are caught early, she said, the five-year survival rate is 85 percent. But in some cases, people have died of HPV-driven cancers. “This is why ensuring that these cancers are caught early is critical,” she said.

What is the treatment?
For many HPV-related cancers, surgical removal of the cancerous tissue is the preferred option for cancers that are caught early. Once the cancer has metastasized, chemotherapy, radiation and even immunotherapy also may be used to slow or stop the spread, experts said.

HPV-related head and neck cancers are less aggressive and often easier to treat than those caused by alcohol or tobacco use, experts said.

How effective is the HPV vaccine?
Experts noted that the best option is to not develop an HPV-driven cancer. The HPV vaccine is one of the most effective tools to protect against oral HPV infection if the vaccine is given before exposure, Moore said. In general, the vaccine can prevent more than 90 percent of HPV-related cancers, the CDC said.

Federal health officials recommend vaccinating boys and girls at age 11 or 12 to protect them before exposure to the virus, with catch-up vaccinations through age 26. Some adults through age 45 who were never vaccinated may still benefit from the shots, according to the CDC. Adults ages 27 to 45 who are interested in vaccination should speak to their doctors, experts said.

“We have 200 different diseases we call cancer,” Knudsen said. “Vaccination is an opportunity for us to wipe out or significantly diminish a large number of cancer types.”