HPV, cervical dysplasia and cervical cancer
Cervical cancer typically develops over a period of years, beginning with a precancerous condition called cervical dysplasia. The cervix is the narrow, lower end of the uterus (womb).
Cervical dysplasia occurs when clusters of abnormal cells form lesions in the mucosa (“wet lining”) of the cervix.
A sexually transmitted virus called human papillomavirus (HPV) causes most cases of cervical dysplasia and cervical cancer. There are different types of HPV. Only some types cause cervical dysplasia and cervical cancer.
Exams and tests can be used to screen for and diagnose cervical dysplasia and cervical cancer. However, cervical dysplasia can be hard to detect through routine exams alone and so regular Pap tests are a good idea.
If treated early, cervical dysplasia is less likely to develop into cervical cancer. Treatments are used to remove the lesions before they turn into cancer.
Cervical cancer is usually treated with radiation and chemotherapy or with surgery, to remove the cancer, slow its growth and/or prevent it from spreading.
People living with HIV have a higher risk of developing cervical cancer. However, with regular gynecological monitoring and care, cervical cancer is not common among people living with HIV in Canada and other high-income countries.
There are several vaccines that can prevent acquiring the most common types of HPV that can lead to cervical cancer.
Consistent and correct condom use reduces, but does not eliminate, the risk of getting HPV or passing it to someone else.
Quitting smoking can help reduce the risk of developing cervical dysplasia and cervical cancer.
The words we use here – CATIE is committed to using language that is relevant to everyone. People use different terms to describe their genitals. This text uses medical terms, such as vagina and penis, to describe genitals. Cisgenderi people can often identify with these terms. Some trans peopleii may use other terms, such as front hole and strapless. CATIE acknowledges and respects that people use words that they are most comfortable with.
What are cervical dysplasia and cervical cancer?
The cervix is the narrow, lower end of the uterus (womb), which connects to the vagina. The cervix can be felt with the tip of a finger inside the vagina. Cervical cancer starts as a precancerous condition called cervical dysplasia (abnormal changes in cells) in the mucosa (“wet lining”) of the cervix. Groups of these abnormal cells form areas of abnormal tissue called lesions. Over time, these lesions can develop into cancer.
Some lesions form but then shrink or disappear; some return after disappearing; and some remain present without changing. Other lesions progress from low-grade to high-grade lesions, which can then progress to cancer. Cervical cancer happens when cells in the cervix grow and multiply uncontrollably, spreading into and damaging surrounding tissue.1–3
What causes cervical dysplasia and cervical cancer?
Almost all cases of cervical dysplasia and cervical cancer are caused by HPV. This makes HPV the most important risk factor for cervical cancer.
HPV is a very common virus. Some types of HPV can be passed on sexually, through bodily fluids, such as semen and vaginal secretions. HPV can also be transmitted through skin-to-skin contact (such as genital-to-genital contact) even when bodily fluids are not present.
There are over 100 different types of HPV. Only some of these types cause cervical dysplasia and cervical cancer. HPV types 16 and 18, in particular, account for most cases of cervical cancer (and anal cancer as well). Other types can cause warts on, in or around the anus or genitals (anogenital warts).
Most sexually active people acquire HPV at some point in their lives. In most cases, the immune system clears the HPV infection without any problems. However, this does not make someone immune to future HPV infections because there are many different types of HPV.
One way in which HPV may cause cancer is by interfering with how the body prevents cancer from developing. The human body produces cells that make proteins, which help prevent dysplasia and cancer. In some cases, HPV can shut off these proteins.2,3
Who is at risk?
Anyone with a cervix who is sexually active can get HPV in the cervix, cervical dysplasia or cervical cancer. HPV can be passed through vaginal sex, anal sex and oral sex (mouth on penis, mouth on vagina). It can also be passed through oral-anal contact (rimming) and through the sharing of sex toys. Having multiple sexual partners increases a person’s risk.
When a person has HPV, other factors can contribute to the development of cervical dysplasia and cervical cancer.
People with weakened immune systems are at greater risk for cervical dysplasia and cervical cancer. This includes people living with HIV. This risk seems to increase as CD4 counts decrease.
Other important risk factors for cervical dysplasia and cervical cancer include cigarette smoking, and history of other sexually transmitted infections. Using oral contraceptives (birth control pills) for a long time also increases the risk.
Having given birth to multiple children is a risk factor for cervical cancer as well; the risk increases with each additional child a person gives birth to after the first. Individuals born to pregnant people who took a form of estrogen supplement called Diethylstilbestrol (DES) during pregnancy are also at higher risk of some kinds of cervical cancer. Symptoms or history of other HPV-related conditions, such as anal cancer, can also indicate that a person is at risk for cervical cancer, because the HPV types that cause these conditions might also cause cervical cancer.
People living with HIV have a higher risk of acquiring an HPV infection and of developing dysplastic lesions.3–7
Individuals with cervical dysplasia often do not experience any clear symptoms until it is advanced or has become cervical cancer. Early stage cervical cancer may not produce any signs or symptoms either. In more advanced cervical cancer, symptoms may include pain in the abdomen or lower back, pain or bleeding while having vaginal intercourse, unusual vaginal discharge, or bleeding between menstrual periods. Some of these symptoms are not specific to cervical cancer, so they may be mistaken for other conditions.
Having anogenital warts may be a sign that a person should be tested for cervical dysplasia or cervical cancer. Even though anogenital warts and cervical cancer are caused by different types of HPV, people with the type(s) that cause anogenital warts are more likely to also have the type(s) that cause cervical cancer. Anogenital warts usually consist of a series of bumps or mini-cauliflower-like growths. These may be easily visible if they are located in, on or around the vagina or anus. Warts on the cervix or in the anal canal may not be detected prior to internal examination.2,3,8
Progression of cervical cancer
The abnormal cells that develop as a result of cervical dysplasia can eventually develop into cervical cancer, particularly if not detected and treated early. If the cancer has spread deeply into the cervix or adjacent tissues, removing the cancer or preventing its spread may require surgical removal of the cervix, uterus and/or other parts of the reproductive system. If cervical cancer is not diagnosed and treated early, the cancer is more likely to spread to other parts of the body. More aggressive cancer treatments may then be required.1,3,8,9
Testing and diagnosis
Regular pelvic examinations including Pap tests and HPV testing can help diagnose or monitor HPV, cervical dysplasia or cervical cancer. National guidelines in Canada recommend routine screening for cervical cancer every three years, starting at age 25, but recommendations differ by province and territory.
Screening for cervical dysplasia and cervical cancer involves the use of a cervical Pap test. To do a Pap test, a healthcare provider inserts a tiny brush and a small wooden spatula into the vagina and rubs them over the cervix to loosen and collect cells. The cells are smeared on a glass slide that is then sent to a laboratory for study. The cells are examined to determine whether they show signs of cervical dysplasia or cervical cancer. Pap tests are also used to “grade” any abnormalities that are found. Low-grade lesions have some chance of leading to cancer. High-grade lesions are more advanced and more likely to develop into cancer.
Although Pap tests are useful, they can produce “false-negative” results. In other words, the lab may report a test result as “normal” when there actually are abnormalities in the cells of the cervix. For this reason, HPV testing may be used in addition to Pap tests during screening. For HPV testing, doctors collect a small amount of fluid from the cervix and have it tested for the presence of HPV. The purpose of this test is to find out what types of HPV are present. Once this is known, the tests can be used to predict the presence of cervical dysplasia or cervical cancer. If Pap tests do not detect these conditions, the presence of HPV may indicate the need for closer examination.
Depending on the results of a Pap Test and/or HPV test, a person may be referred to a specialist (a gynecologist) for a colposcopy. During a colposcopy, a specialist uses a lighted magnifying instrument called a colposcope to look inside the vagina and visually examine the cervix. The cervix is lightly washed with a weak vinegar solution before the colposcope is put in place. The vinegar solution makes abnormal cells stand out more clearly against the surrounding tissue.
During the colposcopy, the specialist may take a biopsy. A biopsy is the removal of a small tissue sample so that it can be checked for the cell abnormalities that characterize cervical dysplasia or cervical cancer. Biopsy is also used to “grade” any abnormalities that are found. Grade 1 (CIN-1) means mild, or low-grade cervical dysplasia which may develop into cancer. Grades 2 and 3 (CIN-2; CIN-3) mean severe or high-grade dysplasia, which are more likely to develop into cancer. A result of “CIS” (carcinoma in situ) means that a small area of cancer has been found.9–14
Notification of partners
HPV is not a reportable infection in Canada. This means that when an infection is confirmed by a clinic, healthcare provider or laboratory it is not required to be reported to public health authorities. Partner notification is not required as a public health measure, unlike with a diagnosis of chlamydia, gonorrhea, syphilis or HIV.15
HPV itself cannot be treated, but the immune system is able to clear most cases of HPV. A variety of treatments are used for cervical dysplasia and cervical cancer. Treatments vary, depending on severity, location and size, and whether any cancer present has spread to other parts of the body. Whether or not the person wishes to become pregnant can also affect treatment decisions. People with cervical cancer may be referred to a gynecologist-oncologist or an oncologist—a doctor who specializes in the treatment of cancer.
There are several ways that cervical dysplasia may be treated:
- Cryotherapy destroys the lesion by freezing. This procedure can be done in the doctor’s office. There can be some discomfort or pain. After the treatment, spotting and watery discharge are common.
- Laser treatment destroys the lesion with an intense beam of infrared light. This procedure is often done in a day-surgery clinic. It can be uncomfortable and can cause spotting and discharge afterward.
- LEEP stands for loop electrosurgical excision procedure. The lesion is surgically removed by an electrical current that passes through a very fine wire loop and cauterizes the cervix at the same time so that it does not bleed afterward.
- Cone biopsy removes a cone-shaped piece of tissue from the opening of the cervix and can remove a lesion or very small cancer. It is usually done in a hospital with a laser or a scalpel and patients are given an anesthetic. Some bleeding and pain or discomfort is common after this treatment.
There are several treatment options if cancer is confirmed:
- Surgery may be used to remove cancerous tissue. If the cancer has spread, surgery to remove the cervix and uterus, called a hysterectomy, may be necessary. Sometimes the fallopian tubes, ovaries and lymph nodes from the pelvis are removed at the same time.
- Radiation therapy is often prescribed for cervical cancer that has spread beyond the cervix. In radiation therapy, high-energy rays are used to kill cancer cells.
- Chemotherapy may be used by itself or in addition to radiation therapy if the cancer has spread. Anticancer drugs are used in the blood to kill cancer cells. 3,11,12
What about HIV?
HIV weakens the immune system which can make a person more vulnerable to some illnesses, including cervical cancer.
Effective HIV treatment (also known as antiretroviral therapy or ART) can reduce the amount of HIV in the body, increase CD4 cell counts, and greatly lowers the risk of developing many illnesses traditionally associated with HIV, including cervical cancer. But even with effective HIV treatment, people living with HIV have a higher risk of HPV-related disease - including faster progression to cancer.
However, studies have found that, with regular gynecological exams and Pap tests, cervical cancer is not common among people living with HIV in high-income countries. Therefore, people with HIV should get regular care, including screening for HPV-related disease and talk with a doctor or nurse about getting vaccinated against HPV if necessary. 16–18
HPV vaccines are widely available and highly effective at preventing certain types of HPV, including those that most often cause cervical dysplasia and cervical cancer.
The vaccines do not provide protection against HPV types that people are already infected with but provide excellent protection against HPV types the person has not been exposed to.
It is also important to remember that even if someone has received one of the vaccines, they are only protected against the cancer-causing HPV types covered by the vaccine they have received.
Different vaccines prevent different types of HPV. Although several vaccines are approved to reduce the risk of HPV infection (and related cancer) in Canada, the most commonly used today reduces the risk of infection with nine types of HPV. This vaccine is called Gardasil-9. It is estimated that HPV vaccination can prevent up to 90% of high-risk, precancerous cervical lesions (high-grade cervical dysplasia) from developing.
Because the types of HPV that cause cervical dysplasia and cervical cancer are transmitted sexually, prevention benefits are greatest if a person is vaccinated before they have had their first sexual encounter. But even if a person is sexually active or has already acquired an HPV infection, vaccination can protect them from getting types of HPV they have not yet acquired.
People living with HIV are at reduced risk from HPV infection when given HPV vaccination.
However, it is unclear whether HPV vaccination is as effective among people living with HIV as it is among people who are not living with HIV.
All provinces and territories provide school-based immunization programs for young people, starting in grades four to seven. “Catch-up” programs are also available in all provinces and territories for people who did not receive vaccination through school-based programs, but availability varies, based on age or sex.
The correct and consistent use of condoms during sex can reduce the risk of getting HPV or passing it to someone else, but does not eliminate the risk completely. This is because HPV can be transmitted from areas of skin not covered by a condom to the skin of a sexual partner.
There are two types of condoms available. The external condom (sometimes called the “male” condom) is a sheath made from polyurethane, latex or polyisoprene that covers the penis during sex. The internal condom (sometimes called the insertive or “female” condom) is a pouch made of polyurethane or a synthetic latex material called nitrile that can be inserted into the vagina or rectum. Some trans men may cut a condom or oral dam to fit their genitals.
The use of condoms or oral dams can reduce the risk of passing on HPV during oral sex or rimming.
When sharing sex toys, using a new condom and cleaning the toy between each use can reduce the risk of HPV transmission.
Quitting or reducing smoking reduces the risk of developing cervical dysplasia and cervical cancer.
Routine screening for cervical dysplasia with Pap tests and HPV tests can increase the chances of catching the dysplasia early, so that it can be treated before cancer develops. 8,17,19–22
i Cisgender – someone whose gender identity aligns with the sex they were assigned at birth
ii Transgender – an umbrella term that describes people with diverse gender identities and gender expressions that do not conform to stereotypical ideas about what it means to be a girl/woman or boy/man in society
(Definitions taken from Creating Authentic Spaces: A gender identity and gender expression toolkit to support the implementation of institutional and social change, published by The 519, Toronto, Ontario.)
Condoms for the prevention of HIV transmission – fact sheet
Safer Sex Guide – client resource
Oral Sex – client resource
Viral STI Basics – fact sheet
Sexually Transmitted Infections – booklet (Public Health Agency of Canada)
This fact sheet was developed in partnership with the Sex Information and Education Council of Canada (SIECCAN).
- Centers for Disease Control and Prevention. STD Facts - Human papillomavirus (HPV). Available at: www.cdc.gov/std/hpv/stdfact-hpv.htm.[Accessed Jan 16, 2023]
- Ontario Ministry of Health. Getting the HPV vaccine. Available at: www.ontario.ca/page/getting-hpv-vaccine . [Accessed Jan 16, 2023]
- World Health Organization (WHO). Cervical cancer. Available at: www.who.int/news-room/fact-sheets/detail/cervical-cancer. [Accessed Jan 16, 2023]
- Alam S, Conway MJ, Chen HS, et al. The Cigarette Smoke Carcinogen Benzo[ a ]pyrene Enhances Human Papillomavirus Synthesis. Journal of Virology. 2008 Jan 15 ;82(2):1053-8
- Chan JK, Berek JS. Impact of the human papilloma vaccine on cervical cancer. Journal of Clinical Oncology. 2007 Jul 10;25(20):2975–82.
- Massad LS, Seaberg EC, Wright RL, et al. Squamous Cervical Lesions in Women With Human Immunodeficiency Virus: Long-Term Follow-up. Obstetrics & Gynecology. 2008;111(6): 1388-93.
- Canadian Cancer Society. Risk factors for cervical cancer. Available at: cancer.ca/en/cancer-information/cancer-types/cervical/risks. [Accessed Jan 16, 2023]
- Public Health Agency of Canada. Canadian Guidelines on Sexually Transmitted Infections – Management and treatment of specific infections – Human papillomavirus (HPV) infections. Available at: www.canada.ca/en/public-health/services/infectious-diseases/sexual-health-sexually-transmitted-infections/canadian-guidelines/sexually-transmitted-infections/canadian-guidelines-sexually-transmitted-infections-33.html#app_d. [Accessed Jan 16, 2023]
- Canadian Cancer Society. Screening for cervical cancer. Available at: cancer.ca/en/cancer-information/cancer-types/cervical/screening. [Accessed Jan 16, 2023].
- Teresa M, Timoney T, Atrio JM, et al. Screening for Cervical Dysplasia and Cancer in Adults With HIV. Johns Hopkins University HIV Clinical Guidelines Program. 2022.
- National Cancer Institute at the National Institutes of Health. Cervical Cancer Screening. Available at: www.cancer.gov/types/cervical/screening. [Accessed Jan 16, 2023]
- Johns Hopkins Medicine. Cervical Biopsy. Available at: www.hopkinsmedicine.org/health/treatment-tests-and-therapies/cervical-biopsy. [Accessed Jan 16, 2023]
- Canadian Cancer Society. Abnormal cervical biopsy results. Available at: cancer.ca/en/cancer-information/cancer-types/cervical/diagnosis/abnormal-cervical-biopsy-results. [Accessed Jan 16, 2023]
- Canadian Task force on Preventive Health Care. Recommendations on screening for cervical cancer. Canadian Medical Association Journal. 2013 Jan 8;185(1):35–45. Available at: canadiantaskforce.ca/guidelines/published-guidelines/cervical-cancer/. [Accessed Feb, 2023]
- Public Health Agency of Canada. Human Papillomavirus (HPV). 2020 Available at: www.canada.ca/en/public-health/services/infectious-diseases/sexual-health-sexually-transmitted-infections/human-papillomavirus-hpv.html#sm. [Accessed Nov 22, 2022]
- Massad LS, Seaberg EC, Watts DH, et al. Low incidence of invasive cervical cancer among HIV-infected US women in a prevention program. AIDS. 2004;18(1): 109-13.
- Staadegaard L, Rönn MM, Soni N, et al. Immunogenicity, safety, and efficacy of the HPV vaccines among people living with HIV: A systematic review and meta-analysis. eClinicalMedicine. 2022;52:101585
- Palefsky JM. Human papillomavirus-associated anal and cervical cancers in HIV-infected individuals: Incidence and prevention in the antiretroviral therapy era. Current Opinion in HIV and AIDS. 2017 Jan; 12(1):26–30.
- Public Health Agency of Canada. Updated Recommendations on Human Papillomavirus (HPV) Vaccines: 9-valent HPV vaccine 2-dose immunization schedule and the use of HPV vaccines in immunocompromised populations. Available at: www.canada.ca/en/public-health/services/publications/healthy-living/updated-recommendations-human-papillomavirus-immunization-schedule-immunocompromised-populations.html. [Accessed Feb 20, 2023]
- BC Centre for Disease Control. Smart Sex Resource: Know Your Chances. Available at: smartsexresource.com/sexually-transmitted-infections/sti-basics/know-your-chances/. [Accessed Nov 28, 2022]
- Lacey CJ. HPV vaccination in HIV infection. Papillomavirus Research. 2019 Dec 1;8: 100174
- Canadian Partnership Against Cancer. Access to HPV immunization across Canada. Available at: www.partnershipagainstcancer.ca/topics/hpv-immunization-policies/access-hpv-immunization/. [Accessed Nov 28, 2022]
Author(s): Miller D