Experts from ٺƵ Discuss the Hidden Dangers of Human Papillomavirus
The incidence of oral cancer, historically linked to smoking and alcohol use, has declined as smoking rates have fallen. Yet one type has reached epidemic proportions. Over the past 30 years, cases of throat cancer, a type of head and neck cancer known as oropharyngeal cancer, have doubled. An estimated 70 percent of throat cancers are attributed to the human papillomavirus, or HPV, the most common sexually transmitted disease. With more than 13,000 new diagnoses of throat cancer each year in the United States, the disease has surpassed cervical cancer as the most common cancer associated with HPV.
As leaders of the Head and Neck Center at ٺƵ Health’s Perlmutter Cancer Center, , and Kenneth S. Hu, MD, are two of the country’s foremost experts on the treatment of throat cancer. Under their direction, the center offers exceptional care and outstanding outcomes to nearly 1,000 patients every year.
Here, they share their insights and perspectives on a disease that disproportionately affects men, and whose numbers in that group are projected to double over the next decade.
HPV Is Common, But Some Types Cause Cancer
An estimated 80 to 90 percent of the population have an infection of HPV, a virus that causes the most common sexually transmitted infection. About 7 percent of people have a form that affects the oral cavity, and 1 percent contract the most pathogenic strains. In most cases, the immune system clears the virus within a year or two, but types 16 and 18 can remain dormant for years, even decades, before precancerous cells give rise to a tumor.
“The virus can go deep within the crypts of the tonsils,” explains Dr. Persky, professor in the at NYU Grossman School of Medicine, “and that’s probably where it often harbors.”
Patients treated for throat cancer by doctors at the Head and Neck Center represent a broad spectrum of the population, but the majority are between 50 and 80 years of age, with men outnumbering women nearly 4 to 1. Typically, the patient is a healthy nonsmoker whose first symptom is a painless lump in the neck, often noticed while shaving, that doesn’t subside after a course of antibiotics or steroids.
“If a patient’s tumor is HPV-positive, the longterm cure rate for most stages is 80 to 90 percent.”
—Kenneth S. Hu, MD, Co-Director of the Head and Neck Center at Perlmutter Cancer Center
Tween and Teenage Boys Are Especially Vulnerable
The risk of contracting a high-risk form of HPV is estimated to be 14 percent for people who have had 1 sex partner, but 5 times greater for those who have had 6 or more partners. Dr. Persky attributes the rise in throat cancer to climbing rates of sexual activity among a younger and younger population. The earlier an exposure to the virus, he explains, the more time it has to develop, making dangerous strains more prevalent. “Many teens and preteens don’t even consider oral sex a form of sex,” he notes, “but it’s a major transmission route for HPV.”
Childhood Vaccination Can Prevent Throat Cancer
There’s no screening test to identify those at risk for developing HPV-positive tumors, but three childhood vaccines have been approved by the U.S. Food and Drug Administration to protect against types 16 and 18. “Throat cancer can be prevented to a great extent if parents have their children vaccinated around age 12, before they become sexually active,” says Dr. Persky. He expects the epidemic to peak around 2040, when the first generation vaccinated as preteens reaches middle age.
The Cure Rate Is Very High
“If a patient’s tumor is HPV-positive, the longterm cure rate for most stages is 80 to 90 percent,” reports Dr. Hu, professor in the Departments of and Otolaryngology—Head and Neck Surgery. HPV-positive tumors are more responsive to chemotherapy and radiation, partly due to the biology of the tumors and partly because healthy nonsmokers tolerate treatment better. Most patients don’t require surgery, notes Dr. Persky, but when they do, the preferred method is robotic surgery, which affords less invasive access to the deep structures of the head and neck.
“The robotic approach has revolutionized surgical treatment,” says Dr. Persky. “The tumor can be identified more easily, exposed better, and removed with fewer functional and cosmetic postoperative issues.” For a small subset of these surgical patients, he adds, there’s actually no need for chemotherapy or radiation.
When It Comes to Chemotherapy and Radiation, Sometimes Less Is More
For patients who do require treatment, the severe discomfort and complications of radiation combined with chemotherapy rank as the biggest concerns, says Dr. Hu. So he is encouraged by the early results of a study under way at Perlmutter Cancer Center to evaluate reduced doses of radiation and chemotherapy to minimize side effects without compromising efficacy.
“We’ve found that if a patient with an early-stage tumor responds rapidly to standard treatment, they can benefit from a midcourse adjustment,” says Dr. Hu. “We can reduce the radiation dose by 15 percent and switch from high-dose chemo to low-dose chemo administered weekly.” For the patients treated with this experimental strategy so far, the success rate has been 90 percent, with less than 10 percent of them requiring surgery. Dr. Hu expects this novel approach to become an established protocol option at Perlmutter Cancer Center within a couple of years.