HPV risk factors: who gets HPV and when it can lead to cancer

What HPV is

HPV is a group of more than 200 related viruses. Some of them are spread through vaginal, anal or oral sex (NCI). The sexually transmitted types fall into two groups (NCI):

• High-risk HPV can cause several types of cancer. NCI names 12 high-risk types: HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59. HPV 16 and HPV 18 cause most HPV-related cancers.
• Low-risk HPV rarely causes cancer, but a few low-risk types can cause warts on or around the genitals, anus, mouth or throat.

Who is at risk of getting HPV

HPV infections are very common. Nearly all sexually active people are infected with HPV soon after they become sexually active (MedlinePlus). NCI says this happens within months to a few years, and around half of these infections are with a high-risk type (NCI).

HPV passes easily between sexual partners. It can spread through any intimate skin-to-skin contact, including vaginal, anal and oral sex. Using condoms correctly lowers the chance of passing HPV but does not prevent it completely (NCI).

Most infections go away

Your immune system usually controls HPV, and the body clears the infection within a year or two (NCI). Most infections go away on their own and do not cause health problems, but some need treatment (MedlinePlus).

What makes a high-risk infection more likely to last

When a high-risk infection lasts for many years, it can lead to cell changes that may get worse over time, become precancer and then cancer if they are not treated (NCI). NCI says research has found it can take 5 to 10 years for HPV-infected cervical cells to become precancer and about 20 years to become cancer (NCI).

For high-risk HPV in the cervix, NCI lists these factors as raising the chance that the infection lasts and leads to precancer (NCI):

• having a very aggressive HPV type, especially HPV 16 or HPV 18
• smoking
• having a weakened immune system
• being infected with HIV
• taking medicines that suppress the immune system, such as after an organ transplant, for an autoimmune disease or for cancer

Because smoking may raise the chance that high-grade cell changes turn into cancer, NCI says it is important to quit. The free quitline is 1-800-QUIT-NOW (800-784-8669) (NCI).

The six cancers HPV can cause

Long-lasting high-risk HPV can cause cancer where it infects cells. NCI gives these shares of each cancer caused by HPV (NCI):

• Cervical cancer: virtually all. See cervical cancer risk factors.
• Anal cancer: over 90%. See anal cancer risk factors.
• Oropharyngeal (throat) cancer: about 70%. This is different from cancer of the mouth itself (oral cavity cancer). See oral cancer risk factors.
• Vaginal cancer: about 75%.
• Vulvar cancer: about 69%. See vulvar cancer risk factors.
• Penile cancer: about 63%. See penile cancer risk factors.

Each year in the United States there are over 47,900 new cancers in parts of the body where HPV is often found, and HPV is estimated to cause about 37,800 of them, based on CDC data reported by NCI (NCI).

Symptoms

Some low-risk types cause warts. High-risk HPV itself causes no symptoms (NCI). If a high-risk infection lasts many years and causes cell changes or cancer, you may have symptoms, and which ones depends on the part of the body affected (MedlinePlus). NCI names lumps, bleeding and pain as examples (NCI).

Vaccines

HPV vaccines can prevent infection with the types that cause disease, and so prevent many HPV-related cancers and cases of genital warts (NCI). NCI says the series is recommended for girls and boys at age 11 or 12 and can start at age 9. Those who start before age 15 get two doses; those who start at 15 or older get three. Vaccination is recommended up to age 26 for those who were not vaccinated earlier (NCI).

The vaccine has FDA approval through age 45 but is not routinely recommended for most people aged 27 to 45, who have likely been exposed to HPV already (NCI). If you are over 26 and not vaccinated, MedlinePlus suggests talking with your provider about the possible benefits (MedlinePlus). Our HPV vaccine age check walks through the age groups.

Screening

Cervical cancer is the only HPV-caused cancer with FDA-approved screening tests: the HPV test, the Pap test, or both together (NCI). See our cervical cancer screening age check. There are no standard screening tests for throat, penile, vaginal or vulvar cancer. For anal cancer there is no standard test for the general public, but an anal Pap test is sometimes used for groups at higher risk of anal HPV infection: men who have sex with men, women who have had cervical or vulvar cancer, people with HIV and organ transplant recipients (NCI).

Because most HPV-related cancers have no screening test, NCI says it is important to follow up with your health care provider about unusual symptoms (NCI).

Common questions

Can HPV infection be treated?

MedlinePlus says the HPV infection itself cannot be treated. Warts and the cell changes caused by high-risk HPV can be treated with medicines put on the area or with procedures (MedlinePlus).

Does having HPV mean I will get cancer?

No. Most infections clear within a year or two. Cancer can follow only when a high-risk infection lasts for many years (NCI).

What lowers the risk of catching HPV?

MedlinePlus says correct use of latex condoms greatly reduces, but does not fully remove, the risk; polyurethane condoms are an option for people allergic to latex. The most reliable way to avoid infection is not having anal, vaginal or oral sex. Vaccines work best when given before exposure, so before people become sexually active (MedlinePlus).