Martina Navratilova's HPV Turned into Cancer. How Does This Happen?

On Jan. 2, tennis legend Martina Navratilova announced that she has two types of cancer, breast and throat, the latter caused by the human papillomavirus (HPV). Her news shines light on HPV, a sexually transmitted infection (STI) that most people encounter, and the cancers it can cause.

“It’s a common virus we come in contact with, and everybody is exposed by the time they are 15,” Dr. Marshall Posner, co-leader of the Cancer Clinical Investigatino Program at The Tisch Cancer Institute at Mount Sinai, tells TODAY.com. “HPV-related cancers are a whole family of cancers, and everybody is exposed to HPV primarily through the exchange of bodily fluids, not blood, but oral cavity saliva and all of the sexual fluids.”

What is HPV?

HPV is a STI that is so ubiquitous that few people even know when they have it. The U.S. Centers for Disease Control and Prevention says it’s “the most common sexually transmitted infection in the United States." Of the 100 different types of HPV, 40 can infect genital areas, the mouth and throat through intercourse and oral sex. Some strains cause genital warts, which can appear on the penis, vagina or anus and are often the only sign that someone has contracted HPV. Most people have no idea they have it, and while it’s transmitted through sexual activity, people can contract it regardless of their number of partners.

About 20% of HPV cancers occur in people with multiple sex partners with the other 80% occurring in people who’ve had one sex partner in their lives, Posner says. “The vast majority of people who get this have not done behaviors that lead them to be at risk.”

HPV-related throat cancer

The CDC says that HPV is to blame for about 70% of oropharyngeal cancers.

“We’ve seen over the last 30 years or so an increase in HPV infections,” Dr. Shauna Campbell, a head and neck radiation oncologist at Cleveland Clinic, tells TODAY.com. “We’ve had an increase in the number of HPV-associated cancers over the last 30 years. ... Overall head and neck cancer is more rare compared with other types of cancers. However, we do see a growing number of HPV associated cancers.”

HPV-caused throat cancer normally occurs in a very specific part of the back of the mouth and throat.

“When people are talking about throat cancer, they’re usually referring these days to what we call oropharynx cancer, which is made up of ... the base of the tongue and the tonsils and is really at the back of the mouth,” Dr. Adam Jacobson, director of the Head & Neck Center at NYU Langone’s Perlmutter Cancer Center, tells TODAY.com. “That tends to be associated with human papillomavirus driven cancer.”

Symptoms of throat cancer include:

• A mass on the neck

• Ear pain on one side that doesn’t go away

• Dry throat that persists

• “Hot potato voice,” when the voice sounds harsh

The good news? These types of cancers respond well to treatment.

“Prognosis is much better in a patient who has human papillomavirus-related throat cancer than in a patient who has a tobacco-related throat cancer. They both develop squamous cell carcinoma, but they’re very different genetically,” Jacobson says. “The ones that are driven by human papillomavirus are much more responsive to treatment with surgery or radiation or chemotherapy or some combination of these three forms of treatment.”

Posner estimates that 90-95% of cases of HPV-related throat cancers can be cured with one or two types of treatment if found early.

"As we get into more advanced stages, we can still cure 85 to 95% percent using a variety of different tools," he adds.

Posner has been involved in research involving robotic surgery and lower doses of radiation to treat HPV-related throat cancers. Combined with surgery, lower doses of radiation seem to be effective at treating the cancers without causing patients too many nasty side effects from the radiation, which can include chronically dry throats and mouths, loss of taste and pain.

“We really reduced the toxicity in the treatment of these cancers,” he says. “We can reduce the dose of treatment that they get substantially so they don’t have to endure the long-term consequences of radiation.”

Cervical cancer

In the United States, about 13,000 people learn they have cervical cancer each year, says Dr. Stephanie Blank. Worldwide, that number is higher, with 600,000 cases diagnosed in 2020. Screening for cell changes in the cervix as part of a Pap smear allows doctors to address pre-cancerous changes.

“A lot of people have HPV infections,” Blank, director of Gynecologic Oncology for the Mount Sinai Health System, tells TODAY.com. “(Cancer) can be shown via the cell changes that happen that can be picked up by a Pap smear.”

The U.S. Preventative Services Task Force recommends that people ages 21 to 65 with a cervix undergo screening every three years with a Pap smear. People under 21, over 65 or who've had a hysterectomy do not need to undergo screening, unless they are at high risk for cervical cancer. A Pap smear can detect pre-cancerous changes that allow doctors to help patients before it develops into cancer.

“People who have abnormal Paps, sort of like the precursors to cervical cancer, having the appropriate follow up and sometimes procedures to remove the changes can prevent cancer,” Blank says. “That’s really important.”

Signs of cervical cancer include:

• Abnormal bleeding between periods

• An unusual discharge

• Bleeding after sex

If it develops into cancer, doctors can use surgery, including removing just the cancer or the entire cervix, to treat it. Cervical cancer in later stages requires additional therapies, such as chemo and radiation.

Treatment for cervical cancer has gotten better over time, but the best strategy to avoid it is to get the HPV vaccine, which has been shown to reduce rates of cervical cancer, Blank explains.

“Nothing is going to work better than prevention," she says.

While it works best when given to people before sexual exposure — it's offered starting at age 11 — people up to age 45 qualify for it. There’s evidence the vaccine prevents cervical cancer, but there’s not enough data yet to say it also prevents HPV-related throat cancers.

“(The vaccine) hasn’t been around long enough for us to know if it’s going to reduce the amount of human papillomavirus-related throat cancer, but we are expecting that it will,” Jacboson says. “The kids who’ve been vaccinated haven’t become adults long enough for us to notice a change in epidemiology of this, but we’re expecting it."

Blank wants more people to learn more info about HPV so it becomes a less taboo topic. Feeling embarrassed about having HPV or gynecological symptoms, such as abnormal bleeding or discharge, can make people hesitant to seek help or talk about it.

“There has been this stigma, and that’s one of the reasons why it’s so important to make people aware honestly that the majority of college-age students have HPV. It’s very very common,” she says. “Diminishing that stigma could potentially help people.”

Why do some people develop HPV-related cancers?

For many people, having HPV doesn’t impact their lives at all. They never develop warts, have an abnormal Pap smear or develop cancer.

“We tend to acquire these infections, usually when we’re a little bit younger through young adulthood,” Campbell says. “Most commonly, (the) body clears the HPV, so they no longer have active HPV in their system. But for a small group of people, their body is not able to clear that virus, and although it may remain dormant for a really long time, at some point, it reactivates and causes a cancer.”

People generally develop HPV-related cancers in their 40s, 50s or 60s, often decades after they were infected. Right now, it’s unclear why some people’s immune systems do not rid them of HPV.

“We don’t have any high-quality evidence which tells us exactly which people are at risk for not clearing the infection. We think there’s a lot of underlying genetic and also different environmental factors, different immune system factors,” Campbell says.

Posner adds: “If we knew what would cause people to develop a cancer, we would be very much looking for a way to circumvent that. ... Right now, the best way to treat HPV cancer is to get the vaccine and never risk an infection in the future.”

This article was originally published on TODAY.com