Understanding HPV and Cancer
What is HPV?
Human papillomavirus (HPV) is a highly common group of viruses of which there are more than 200 types. Most types of HPV cause common warts and are spread through non-sexual contact, such as skin-to-skin touching or contact with contaminated surfaces. Approximately 40 types of HPV can infect the genital area (vulva, vagina, vervix, penis, scrotum, anus), mouth, or throat, and are spread through sexual contact (CDC, 2021). Sexually transmitted HPV the most common sexually transmitted infection in the world- in fact, 80% of sexually active individuals will experience an HPV infection at some point during their lifetime (NFID, 2022). While most sexually transmitted HPV infections clear themselves over time, some can persist in the body and cause health problems. Some types of sexually transmitted HPV cause genital warts. While unpleasant, this form of HPV is considered low-risk as it is not linked to cancer or other health problems. However, certain types of sexually transmitted can lead to cancer, and are also known as high-risk HPV (NIH, 2021). This article will explain how HPV is linked to cancer and how to reduce your risk of complications from high-risk HPV.
How is HPV transmitted?
Sexually transmitted HPV is spread through having vaginal, anal, or oral sex with someone who has the virus, or having close skin-to-skin contact. This means that HPV can sometimes still be transmitted even if a condom or other barrier is used, or if intercourse does not occur (NIH, 2021). A person with HPV can also transmit the virus even if they are not having any symptoms. This is why HPV is so common- most people are not aware that they have the virus, and pass it to others unknowingly. Furthermore, there are limited tests available for HPV- there are currently no approved HPV tests for men, and most tests for women only check for high-risk types (NIH, 2021).
Most of the time, the body’s immune system clears HPV from the body within two years of infection, and nearly everyone who has sex will have HPV at some point in their life (Radboud UMC, 2022). This is why there’s no need to feel ashamed or scared if you find that you have HPV- it is very common and sometimes difficult to detect. Furthermore, although there is no cure for HPV, most people will naturally clear the infection without any treatment.
How does HPV cause cancer?
As mentioned, the body’s immune system often naturally cures high- and low-risk HPV within a few years of being infected. However, in some cases, the infection does not clear and persists in the body. When high-risk HPV remains in the body, it can infect other body cells and cause changes to cell DNA. Over time, this can make cells begin to grow uncontrollably, which can lead to cancer (CDC, 2021).
What types of cancer does HPV cause?
Cervical cancer is the main cancer that is linked to high-risk HPV. Most cases of cervical cancer are caused by HPV. Additionally, most cancers of the vagina, vulva, penis, and anus are also caused by HPV, as well as most oropharyngeal cancers (such as the tonsils and base of the tongue). HPV presents a cancer risk in both women and men, which is why preventing HPV infections should be a priority for everyone (CDC, 2022).
Number of cancers caused by HPV in the US, 2020
|Cancer||Cases in Women||Cases in Men|
|Back of the Throat||2,200||11,800|
What types of high-risk HPV cause cancer?
There are approximately 14 high-risk HPV types associated with cancer. However, the majority of HPV-related cancers are caused by types 16 and 18. HPV types 16 and 18 are responsible for 70% of cervical cancers and precancerous lesions. Other high-risk types of HPV are: 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68 (NIH, 2021).
How do I know if I have high-risk HPV?
Unlike low-risk HPV that can cause visible genital warts, high-risk HPV has no symptoms until after cell changes or cancer occurs. HPV-related cell changes to the cervix are most commonly checked with a Pap smear, a test in which a sample of cells are taken from the cervix to check for cancer or precancerous cell changes (NIH, 2021). In recent years, HPV tests have become more widely used for checking infections of the vulva, vagina, or cervix. These tests can detect high-risk HPV infections, but not whether cell changes have occurred. This means that if the result of an HPV test is positive, a follow-up Pap smear is required. For more information on the difference between HPV testing and Pap smears, click here. Unfortunately, there is currently no approved HPV test for infections of the penis, anus, mouth, or throat. This is why prevention of high-risk HPV is beneficial for everyone.
Homed-IQ now offers an at-home HPV Tests for Women. This preventive health test checks for high-risk HPV types using a vaginal swab and can be performed in the privacy of your home. Home HPV testing may be useful for individuals who want to know if they are currently infected with high-risk HPV but are not eligible for government screening, or face other barriers accessing HPV-related testing. However, HPV testing cannot diagnose cervical cell changes or cancer, and a follow-up Pap smear is always required after a positive HPV test.
How can I limit my risk of cancer from HPV?
The most effective way to prevent high-risk HPV infections in both men and women is getting vaccinated against HPV. The HPV vaccine protects against the most high-risk forms of HPV, including types 16 and 18, as well as the most common strains that cause genital warts (CDC, 2021). HPV vaccination is the most effective if it is administered before you start having sex, but even if you are already sexually active it is still a good decision to get vaccinated. The CDC and the Dutch Public Health Institute (RIVM) recommends that men and women before age 26 are vaccinated (CDC, 2022) (RIVM, 2022). Vaccination is not recommended for most people older than 26 as HPV infection in this age range provides less benefit. However, adults 27-45 years may decide to get the HPV vaccine after speaking to their GP.
While government screening programs in different countries may only offer HPV vaccinations to women, men should consider vaccination to lower their own risk of cancer and prevent spreading HPV to female partners. In addition to vaccination, safe sex practices such as condom use reduce the risk of HPV, although they do not provide perfect protection (CDC, 2022).
Finally, getting screened is an important way to prevent cervical cancer or catch it in an early stage. While testing guidelines vary by country, it is recommended to follow all local guidelines for screening using either HPV testing or Pap smears. In the future, it is hoped that deaths from HPV-related cancers can be significantly reduced through population-wide vaccination and regular screening.
CDC. (2022, April 12). Std Facts – Human papillomavirus (HPV). Centers for Disease Control and Prevention. Retrieved August 25, 2022, from https://www.cdc.gov/std/hpv/stdfact-hpv.htm
Centers for Disease Control and Prevention. (2021, December 13). Basic information about HPV and cancer. Centers for Disease Control and Prevention. Retrieved August 25, 2022, from https://www.cdc.gov/cancer/hpv/basic_info/index.htm#:~:text=More%20than%2040%20HPV%20types,of%20the%20mouth%20and%20throat.
Centers for Disease Control and Prevention. (2022, February 28). Cancers caused by HPV. Centers for Disease Control and Prevention. Retrieved August 25, 2022, from https://www.cdc.gov/hpv/parents/cancer.html
HPV (human papillomavirus). National Foundation for Infectious Diseases. (2022, August 5). Retrieved August 25, 2022, from https://www.nfid.org/infectious-diseases/hpv/
National Institutes of Health. (2021, October 25). HPV and cancer. National Cancer Institute. Retrieved August 20, 2022, from https://www.cancer.gov/about-cancer/causes-prevention/risk/infectious-agents/hpv-and-cancer#:~:text=Low%2Drisk%20HPVs%20mostly%20cause,59%2C%2066%2C%20and%2068.
RIVM. (2022). Vaccination for HPV. Rijksvaccinatieprogramma.nl. Retrieved August 25, 2022, from https://rijksvaccinatieprogramma.nl/vaccinaties/hpv
Radboud UMC. (2022). Cervical cancer and HPV. Radboudumc. Retrieved August 20, 2022, from https://www.radboudumc.nl/en/research/themes/womens-cancers/cervical-cancer-and-hpv
Generally, HPV does not cause any symptoms. Some types of low-risk HPV can cause genital warts on the vulva, vagina, cervix, penis, scrotum, or anus. Genital warts are harmless and fleshy bumps that sometimes resemble cauliflower in texture. These warts are usually painless and can often be removed like other warts that occur on the hands or feet.
High-risk HPV does not cause any symptoms or genital warts. However, high-risk HPV infections can cause various types of cancer. While high-risk HPV is most commonly associated with cervical cancer, it can also cause cancers of the penis, vagina, anus, and the oropharyngeal area. As high-risk HPV does not cause symptoms until cell changes or cancer occurs, vaccination and testing where available is recommended.
Yes! While HPV has often been considered a “women’s disease”, HPV infects men and women similarly and may even be more common in men. However, because high-risk HPV causes the most cancers in women (in the form of cervical cancer), women are primarily targeted for testing and vaccination. Furthermore, testing for men is not widely available and not possible for infections of the penis, meaning it is more difficult to diagnose men with HPV unless they develop genital warts. However, HPV can also lead to cancers in men and/or be passed to female sexual partners. Therefore, prevention of this disease is important in both men and women.
While initial HPV vaccination programs only targeted women and girls, new guidelines state that both boys and girls are vaccinated. It is hoped this will decrease the number of high-risk HPV infections in both men and women, as well as reduce the number of HPV-related cancers.
HPV does not have a cure or treatment. However, most people’s immune systems will clear the virus within a few years of infection- while many people get HPV during their life, only a small amount do not clear the virus from their body eventually. Additionally, genital warts caused by low-risk HPV can be removed, but this does not cure the infection. Similarly, the cervical cell changes caused by high-risk HPV can be treated but the infection itself cannot be cured.
For most women HPV does not pose a risk to a developing baby and the risk of passing HPV/genital warts to a baby is very low. However, if you have a known history of HPV, genital warts, or cell changes in the cervix be sure to inform your doctor so your health can be monitored. The hormonal changes that occur during pregnancy can sometimes speed up cell changes in the cervix or the growth of genital warts.
Although they have similar names, HPV and herpes are entirely different viruses. While they can both be transmitted through skin-to-skin contact, they are not related. While herpes often causes painful sores around the mouth and genitals, only some types of HPV cause genital warts, which are usually painless. Additionally, high-risk HPV can cause cancer while no forms of herpes are associated with cancer.
Currently there are only HPV tests available for high-risk types of the virus. Testing is also only available for infections of the cervix/vagina, involving a swab or Pap smear. There is no widely approved HPV test for men. However researchers are investigating the possibility for using HPV swab tests for anal and oral infections in men and women, which may become widely available in the future.
If you suspect you have genital warts see your doctor to rule out other conditions. However, the warts do not need to be removed unless they are causing discomfort. Furthermore, if you are eligible for cervical cancer screening or experience the following symptoms, see your doctor to discuss high-risk HPV testing or Pap smears:
- Bleeding between periods or after menopause
- Menstrual bleeding that is longer or heavier than usual
- Pain during intercourse
- Bleeding after intercourse
- Pelvic pain
- A change in your vaginal discharge, such as more discharge or a strong or unusual colour/smell
HPV infections are very common. Risk factors for HPV include:
- Number of sexual partners: the more sexual partners you have, the higher the chance that you may be infected with HPV. This could mean you have multiple partners or you have one partner that has multiple partners.
- Weakened immune system: you are more likely to develop an HPV infection if your immune system is weakened, such as if you take immune-suppressing drugs
- Sexual activity without protection: while the use of condoms and other barriers cannot completely prevent HPV, it lowers your risk of infection
Risk factors for cervical cancer: