Human papillomavirus (HPV) and cervical cancer are often linked in medical conversations, but what are the differences between the two and how are they connected?
What is HPV?
Human papillomaviruses (HPVs) are a group of over 200 related viruses. More than 40 of them are easily spread through direct sexual contact. Other HPV types, such as those that cause non-genital warts, are not sexually transmitted.
HPV is the most common sexually transmitted infection (STI) in the United States. Approximately 14 million new genital HPV infections occur annually. The Center for Disease Control (CDC) estimates more than 90% of sexually active men and more than 80% of sexually active women will be infected with one type of HPV at some point in their lives.
Sexually transmitted HPV types fall into two categories: low risk and high risk. Low risk HPVs do not cause cancer, but may cause skin warts on or around the genitals and anus. High risk HPVs account for around 12 types of HPVs and may cause cancer. Of the high risk HPV types, types 16 and 18 are responsible for most HPV-caused cancers. Of those that are infected with HPV, the CDC estimates that nearly 50% are with a high risk HPV type.
Most high-risk HPV infections occur without any symptoms, go away within 1 to 2 years, and do not cause cancer. Some HPV infections, however, can persist for many years. Persistent infections with high-risk HPV types can lead to cell changes, if untreated, may progress to cancer.
What is Cervical Cancer?
Cervical cancer occurs when abnormal cells on the cervix, the lower part of the uterus that opens into the vagina, grow out of control. Cervical cancer occurs most commonly in midlife, which accounts for nearly half of those diagnosed being between the ages of 35 and 55 years old. Approximately one-fifth of diagnoses are made in women over the age of 65. It rarely impacts those under the age of 20.
More than 13,000 women in the US are diagnosed with cervical cancer each year. While worldwide it is the second most common cancer type for women, it is also one of the most preventable types of cancer, with mortality rates decreasing by an estimated 2% each year. It is often successfully treated when detected early.
The Connection Between HPV & Cancer
HPV is found in about 99% of cervical cancers and more than 70% of cervical cancer cases are attributed to two types of high risk HPV, 16 and 18. While it’s important to note that the majority of women infected with the HPV virus do not develop cervical cancer, a small number of women who do not have their infection resolved may develop a ‘persistent infection.’ Those with persistent infections are at higher risk of developing cervical cell abnormalities and cancer than those who have HPV infections that resolve. About 10% of women with high-risk HPV will develop long-lasting HPV infections, putting them at risk for cervical cancer.
While cervical cancer is by far the most common high risk HPV-related disease, there is increasing research showing HPV can also be linked to cancers of the anus, vulva, vagina, and penis. These types of cancers occur less frequently than cervical cancer, however their association with HPV makes them potentially preventable using similar screening strategies as those used for cervical cancer.
Importance of Screening, Early Detection, & Prevention
Screening and early detection are key to prevention and treatment of cervical cancer. The American Cancer Society estimates 4,000 lives annually are saved by cervical cancer screening. Widespread screening has cut cervical cancer’s incidence and mortality by 50% over the past 30 years.
Two screening tests can help prevent or provide early detection of cervical cancer. The pap test can help medical professionals detect pre-cancers, cell changes on the cervix that may become dangerous if untreated. The HPV test looks for the virus that can cause the cell changes. Read below for details and recommendations on screening tests.
One way to mitigate the risk of HPV and cervical cancer is to get vaccinated when you are young. There are currently three approved HPV vaccinations available: Gardasil®, Gardasil-9®, and Cevarix®. Check with your healthcare provider to see if vaccination is an appropriate route for you to take in preventing HPV infection.
HPV is passed by oral and penetrative sex. Practicing safe sex is another way to avoid contracting HPV. Use a condom every time you have sex, but know that condoms do not prevent against HPV 100% of the time. A monogamous sexual relationship with two partners who do not test positive for HPV will also prevent HPV infection. Note that HPV cannot be passed through casual contact, such as shaking hands, from surfaces like a toilet seat, or from swimming pools.
The Pap test is recommended for all women between the ages of 21 and 65 years old and can be completed in your doctor’s office or at a clinic. You should start getting regular Pap tests at age 21. Starting at age 30, you may also elect to have an HPV test along with the Pap test. Both tests can be performed by your doctor, at the same time. If you are between the ages of 21 and 65, it is important to continue getting routine Pap tests, as directed by your doctor, even if you are not sexually active. If you are older than age 65, have had normal Pap test results for several years, and have had your cervix removed as part of a non-cancerous total hysterectomy, your doctor may determine that Pap tests are no longer necessary.
Learn more about early detection from the American Cancer Society’s guidelines.
At Northwest Primary Care, our women’s health experts are here to help determine a cervical cancer and HPV testing plan that is right for you.