The most significant risk factor for cervical cancer is infection with human papillomavirus (HPV). Researchers now believe that more than 90 percent of cervical cancers are caused by HPV, a commonly occurring virus that will infect more than two-thirds of all sexually active women within their lifetimes.
For more than two decades it has been known that papillomaviruses can cause cervical dysplasia, or precancers. More recently, DNA from these viruses has been found to exist in virtually all cervical squamous cell carcinomas (the most common type of cervical cancer).
Other risk factors for cervical cancer include:
- early age at first sexual intercourse
- having many sexual partners
- giving birth to many children
- smoking cigarettes (which produces chemicals that can damage cervical cells, making them more vulnerable to infection and cancer)
- using oral contraceptives
- infection with HIV (which reduces the body’s ability to fight off HPV infection and early cancers)
By avoiding these known risk factors, women can reduce their likelihood of developing cervical cancer. Women without these risk factors rarely develop cervical cancer.
According to the American Cancer Society, although all women can help protect themselves from HIV and other sexually transmitted diseases by having their partners use condoms, condoms do not provide complete protection from HPV. Using condoms probably reduces the rate of infection by about 70 percent. This is because HPV (unlike HIV) can be spread by physical contact with any infected area of the body.
Importance of the Pap Test & Additional Testing
The Pap test can detect HPV infection and precancers years before cervical cancer develops. Our doctors recommend that women have their first cervical cancer screening about three years after their first sexual intercourse or by the age of 18 — whichever comes first.
If a woman has an ambiguous or positive Pap test, an HPV-DNA test (Digene® HPV Test) is performed to identify the presence of any of the 13 high-risk types of HPV associated with the development of cervical cancer. The test can detect these high-risk types of HPV even before there are any visible changes to the cervical cells. The role and usefulness of HPV testing as an alternative or additional test to primary Pap screening continues to evolve.
Treatment of these conditions can halt invasive cancer before it starts.
HPV Vaccines
While the vast majority of sexually transmitted HPV infections are harmless and disappear without treatment, certain high-risk strains of the virus that persist in the body may develop into cervical cancer or genital warts (warts that typically appear around the genitals or anus). Because of the strong connection between HPV and cervical cancer, scientists are working to develop vaccines to target the virus strands most likely to turn into cancer.
Video
Learn about the importance of the HPV vaccine for preventing cervical cancer and head and neck cancers.
(5:00)
The first of these vaccines approved by the FDA is Gardasil®, or quadrivalent human papillomavirus (types 6, 11, 16, 18) recombinant vaccine. The vaccine specifically targets HPV types 16 and 18 (which cause about 70 percent of cervical cancer cases) and types 6 and 11 (which cause approximately 90 percent of genital wart cases).
This vaccine can only be used to prevent an HPV infection and is not meant for women who already have an infection. Additional studies are underway to identify vaccines that target other types of HPV, for men and women who already have HPV, and for women with advanced or recurrent cervical cancer.
Women interested in learning more about these vaccines and ongoing clinical trials should contact their physician. Information about clinical trials is available from the National Cancer Institute’s Cancer Information Service and ClinicalTrials.gov (maintained by the National Institutes of Health).
Our Cervical Cancer Screening Guidelines
Memorial Sloan-Kettering Cancer Center recommends that women undergo screening for cervical cancer in the following situations. We provide cervical cancer screening services at the Breast Examination Center of Harlem.
First Screening
Our doctors recommend that women have their first cervical cancer screening at 21 years, regardless of age of first sexual intercourse.
Women Up to Age 30
For women up to the age of 30 years old, our doctors recommend cervical cytology testing (which can include Pap smears or liquid-based cytology) every two years.
Women 30 Years and Older
For women 30 years and older, our doctors recommend one of the following three screening options:
- Cervical cytology testing (which can include Pap smears or liquid-based cytology) every two years
- For women who have had three negative or satisfactory annual cytology tests, cytology testing every three years
- If both the cytology and the DNA tests are negative, screening should occur every three years.
In addition, women of any age who are immunocompromised (due to organ transplant, HIV infection, cancer chemotherapy, chronic steroid use for chronic renal or bowel disease, etc.) or who were exposed in utero to DES (a nonsteroidal synthetic estrogen drug) should be screened annually.
