Most cases of cervical cancer are caused by long-term infection of certain types of human papillomavirus (HPV), which is a common sexually transmitted infection. Not all women with HPV will develop cervical cancer; most cases will be resolved without treatment. Of the more than 100 types of HPV, only 13 are considered at high risk of causing cancer, with HPV types 16 and 18 causing 70% of all cervical cancer cases. Precancerous lesions take many years to develop into cancer and are easy to treat. In women without weakened immune systems, cervical cancer has a long precursor stage (precancer) that can last many years before becoming invasive. However, HIV accelerates the progress of the disease.
Cervical cancer can be prevented. HPV vaccines are safe and can effectively prevent infections from HPV and, therefore, most cervical cancers. Vaccines cannot treat pre-existing HPV infections.
Screening women who do not have symptoms for precancerous lesions or cancer can reduce a woman’s chances of dying of cervical cancer.
The 5-year survival and treatment success is greatest when cervical cancer is found and treated in the early stages. It becomes more difficult to treat once it spreads out of the cervix. Cervical cancer treatments include surgery, radiation and chemotherapy, or a combination of these treatments.
Women ages 30–49 should be screened for cervical cancer at least once. Younger women should be screened if they are at risk of high-grade precancerous lesions. All women with positive screening results should receive effective treatment. Women who test negative should be re-screened in 3–5 years. All girls and women who test positive for HIV and have initiated sexual activity should be screened for cervical cancer, regardless of age. Available screening tests include an HPV test, visual inspection with acetic acid and cytology (Pap test).
As a public health intervention, screening reduces cervical cancer rates by detecting precancerous conditions before they progress to cancer. Screening can also detect early-stage cervical cancer, which is treatable. To be effective, screening must be linked to treatment.
The US Centers for Disease Control and Prevention recommends that all girls and boys aged 11–12 get the recommended series of HPV vaccine. It recommends the HPV vaccine for young women through age 26 and young men through age 21. (The US Food and Drug Administration has approved Gardasil 9 for women up to age 45.) However, for settings with limited resources, the target population is young adolescent girls, aged 9–14. Several studies have shown that the inclusion of boys is not incrementally cost-effective in low-resource settings.
Women infected with HIV have weakened immune systems and, compared to women who are not infected with HIV, have higher incidence, greater prevalence and longer persistence of HPV infection, which can lead to cervical abnormalities and cancer. Consequently, they also have a higher risk of developing precancerous cervical lesions and have more rapid progression to cancer than women who are not infected with HIV. Women infected with HIV are three times more likely than the general population to be diagnosed with cervical cancer. Because HIV-infected women have a higher risk of cervical cancer, they should be screened regularly. All girls and women who test positive for HIV and have initiated sexual activity should be screened for cervical cancer, regardless of age.