Story URL: http://news.medill.northwestern.edu/chicago/news.aspx?id=202532
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Data from the Centers for Disease Control and Prevention. Produced by Zen Vuong/MEDILL
Though experts are not sure why some races are more affected by HPV-associated head and neck cancer, Dr. Alexander speculates the higher HIV-infection rates among black and non-Hispanic people might explain the larger numbers. HIV is a risk factor of head and neck cancer.
HPV exposure increases men’s risk of cancer
by Zen Vuong
March 06, 2012
Data from the Centers for Disease Control and Prevention. Produced by Zen Vuong/MEDILL
Head and neck cancers are catching up to cervical cancer; however, this number is also affected by factors aside from HPV-16, such as HIV and smoking.
The culprit is sexually-transmitted human papillomavirus-16. Human papillomavirus-positive head and neck cancer cases have been rising about 3 percent every year for the last three decades, said Cohen of The University of Chicago Medicine, an institution that includes the University of Chicago Hospitals. HPV-16 infection is three times more likely in men than in women, he added.
Cells of the upper respiratory system of both men and women are very similar to the surface of the cervix in women, said Dr. Kenneth Alexander, chief of infectious diseases at The University of Chicago Medicine.
HPV is linked to cervical cancer as well.
The Centers for Disease Control and Prevention estimates 10,800 new cases of HPV-associated cervical cancer in the United States each year. This number is nearly 35 percent larger than the 7,100 cases of HPV-associated head and neck cancers found in the United States each year.
Oral sex is “probably the most important risk factor” in contracting HPV-16-related head and neck cancer, which “will become more common than cervical cancer in this decade,” he added.
Some 5,600 men are diagnosed with HPV-associated head and neck cancers each year, whereas only 1,500 women suffer the same fate, according to the CDC.
HPV-16, one of more than 150 strains, is a sexually transmitted condition. More than 40 HPV types can be sexually transmitted, according to the National Cancer Institute.
HPV-18 and HPV-16 account for 80 percent of cervical cancers, but the number of these cases is decreasing because regular Pap smears have enabled early detection of precancerous cells, Alexander said.
That’s because screening processes of oropharyngeal, or head and neck cancers, do not yet exist. Problems arise because HPV-infected cells are generally snuggled into tonsil crevices or crypts.
“The tonsil, instead of being smooth like a piece of leather, looks more like the inside of an English muffin,” Alexander said, making it hard get to the HPV-infected specimen by sampling the surface of the tonsil or base of the tongue.
Kevin McConnell, 51, a business developer who lives in Annapolis, Md., discovered he had a tumor in the back of his tongue six years ago. He said he ignored a sore throat and earache for nearly a month, but finally went to see his doctor when his tongue started hurting.
“You have a small lesion in the back of your tongue. It’s not a big deal,” he recalls the physician saying
But McConnell had researched his symptoms online and said he believed he had throat cancer, so he went to The John Hopkins Hospital. Doctors told him he could have surgery to replace the right side of his tongue with a part of his thigh or be treated with chemotherapy and radiation, he said.
He chose not to slice his tongue. Even though McConnell is now in remission, he said he still has discomfort in his tongue and said he probably always will.
“I have trouble swallowing. There are only certain things I can eat [because] my salivary glands were fried by the radiation,” McConnell said. He mostly eats foods with a lot of sauce or juice, he said.
HPV-positive head and throat cancer patients have a 50 percent increased chance of being cured than other types of oropharyngeal cancers, Cohen said. Yet HPV-16-infected cells do not inevitably become abnormal, cancerous cells.
“The great majority of patients who are infected never develop cancer,” he said.
In 90 percent of cases, the immune system naturally eradicates HPV from the body within two years, according to the CDC. But the remaining 10 percent adds up to about 13,700 newly diagnosed cases of all HPV-associated cancers, including cervical, anal and vulvar, reported the CDC.
Although there isn’t a specific vaccine for HPV-16-based oropharyngeal cancer, HPV-associated cancers could be reduced if more people between the ages 9 and 26 complete a three-shot series of the human papillomavirus vaccine. Even though there are two types of vaccine for women, only Gardasil has been tested and licensed for use in males.
Gardasil, also protects against HPV types 6 and 11, the two strains that cause most genital warts in men and women.
Social conservatives such as Michele Bachmann say the vaccine encourages promiscuity. One of them, But Alexander said this political stance is taken because people “don’t understand the epidemiology of the disease.
“Some parents and policymakers underestimate the intelligence of our young people. Young people understand that a dose of vaccine is not permission to go out and have unsafe sex,” he said.
An American’s lifetime risk of contracting a genital HPV infection is 80 percent, Alexander said. “I’m pretty sure 80 percent of us are not immoral,” he said.
