Cervical Cancer Prevention (PDQ®)
What is prevention?
Cancer prevention is action taken to lower the chance of getting cancer. By preventing cancer, the number of new cases of cancer in a group or population is lowered. Hopefully, this will lower the number of deaths caused by cancer.
To prevent new cancers from starting, scientists look at risk factors and protective factors. Anything that increases your chance of developing cancer is called a cancer risk factor; anything that decreases your chance of developing cancer is called a cancer protective factor.
Some risk factors for cancer can be avoided, but many cannot. For example, both smoking and inheriting certain genes are risk factors for some types of cancer, but only smoking can be avoided. Regular exercise and a healthy diet may be protective factors for some types of cancer. Avoiding risk factors and increasing protective factors may lower your risk but it does not mean that you will not get cancer.
Different ways to prevent cancer are being studied, including:
General Information About Cervical Cancer
Cervical cancer is a disease in which malignant (cancer) cells form in the cervix. The cervix is the lower, narrow end of the uterus (the hollow, pear-shaped organ where a fetus grows). The cervix connects the uterus to the vagina (birth canal).
Cervical cancer usually develops slowly over time. Before cancer appears in the cervix, the cells of the cervix go through a series of changes in which cells that are not normal begin to appear in the cervical tissue. When cells change from being normal cells to abnormal cells, it is called dysplasia. Depending on the number of abnormal cells, dysplasia may go away without treatment. The more abnormal cells there are, the less likely they are to go away. Over time, dysplasia that is not treated may turn into cancer. The cancer cells grow and spread through the cervix. It can take many years for dysplasia to turn into cancer.
See the following PDQ summaries for more information about cervical cancer:
Cervical Cancer Prevention
- Avoiding risk factors and increasing protective factors may help prevent cancer.
- The following are risk factors for cervical cancer:
- HPV infection
- Having a weakened immune system
- DES exposure
- In women with HPV infection, other risk factors are also associated with an increased risk of cervical cancer.
- Many full-term pregnancies
- Long-term use of oral contraceptives
- The following protective factors
decrease the risk of cervical cancer:
- Avoiding sexual activity
- Getting an HPV vaccine
- Using barrier protection during sexual activity
- Cancer prevention clinical trials are used to study ways to prevent cancer.
- New ways to prevent cervical cancer are being studied in clinical trials.
Avoiding risk factors and increasing protective factors may help prevent cancer.
Avoiding cancer risk factors may help prevent certain cancers. Risk factors include smoking, being overweight, and not getting enough exercise. Increasing protective factors such as quitting smoking, eating a healthy diet, and exercising may also help prevent some cancers. Talk to your doctor or other health care professional about how you might lower your risk of cancer.
The following are risk factors for cervical cancer:
Infection with human papillomavirus (HPV) is the most common cause of cervical cancer. HPV infections that cause cervical cancer are spread through sexual contact. There are more than 80 types of human papillomavirus and about 30 of these can infect the cervix. HPV types 16 and 18 are most often linked to cervical cancer.
Most of the time, the body’s immune system can fight the HPV infection. Only a very small number of women infected with HPV develop cervical cancer.
Having a weakened immune system
Having a weakened immune system caused by immunosuppression increases the risk of HPV infection and cervical cancer. Immunosuppression is a condition in which the body's immune system is weakened and its ability to fight infections and other diseases is lessened. Long-term immunosuppression may increase the risk of cervical cancer because it lowers the body's ability to fight HPV infection.
Immunosuppression can be caused by the following:
- Human immunodeficiency virus (HIV). This virus causes AIDS and weakens the body's immune system. Women who are infected with the HIV virus have an increased risk of HPV infection and cervical cancer compared with women who are not infected with HIV.
- Medicine to prevent organ rejection after transplant. Women who have an organ transplant are given medicine to weaken the body’s immune system and help prevent organ rejection.
Being exposed to a drug called diethylstilbestrol (DES) while in the mother's womb increases the risk of cervical dysplasia and clear cell adenocarcinoma of the vagina and cervix. Between 1940 and 1971, DES was given to some pregnant women in the United States to prevent miscarriage (premature birth of a fetus that cannot survive) and premature labor.
In women with HPV infection, other risk factors are also associated with an increased risk of cervical cancer.
Many full-term pregnancies
Among women who are infected with HPV, those who have had 7 or more full-term pregnancies have an increased risk of cervical cancer.
Long-term use of oral contraceptives
Among women who are infected with HPV, those who have used oral contraceptives ("the Pill") for 5 to 9 years have a risk of cervical cancer that is 3 times greater than that of women who have never used oral contraceptives. The risk is 4 times greater after 10 or more years of use. In women who stop taking oral contraceptives, over a 10 year period, the risk of cervical cancer returns to that of women who never used oral contraceptives.
Women who either smoke cigarettes or breathe in secondhand smoke have an increased risk of cervical cancer. The risk increases with the number of cigarettes smoked per day and how long the woman has smoked. Among women infected with HPV, current and former smokers have 2 to 3 times the risk of cervical dysplasia and invasive cervical cancer.
The following protective factors decrease the risk of cervical cancer:
Avoiding sexual activity
Almost all cases of cervical cancer are caused by HPV infection, which is spread through sexual activity. Cervical cancer is seen more often in women who are sexually active at an early age and who have multiple sexual partners.
Getting an HPV vaccine
Vaccines that protect against HPV infection greatly reduce the risk of cervical cancer. These vaccines do not protect women who are already infected with HPV.
Several HPV vaccines have been approved by the U.S. Food and Drug Administration (FDA). These vaccines have been shown to prevent infection with the types of HPV that cause most cervical cancers. Protection against HPV infection lasts for 6 to 8 years. It is not known if the protection lasts longer.
Using barrier protection during sexual activity
Some methods used to prevent sexually transmitted diseases (STDs) decrease the risk of HPV infection. The use of a barrier method of birth control, such as a condom or diaphragm, helps protect against HPV infection.
Cancer prevention clinical trials are used to study ways to prevent cancer.
Cancer prevention clinical trials are used to study ways to lower the risk of developing certain types of cancer. Some cancer prevention trials are conducted with healthy people who have not had cancer but who have an increased risk for cancer. Other prevention trials are conducted with people who have had cancer and are trying to prevent another cancer of the same type or to lower their chance of developing a new type of cancer. Other trials are done with healthy volunteers who are not known to have any risk factors for cancer.
The purpose of some cancer prevention clinical trials is to find out whether actions people take can prevent cancer. These may include eating fruits and vegetables, exercising, quitting smoking, or taking certain medicines, vitamins, minerals, or food supplements.
New ways to prevent cervical cancer are being studied in clinical trials.
Clinical trials are taking place in many parts of the country. Information about clinical trials can be found in the Clinical Trials section of the NCI website. Check NCI's list of cancer clinical trials for cervical cancer prevention trials that are now accepting patients.
About This PDQ Summary
Physician Data Query (PDQ) is the National Cancer Institute's (NCI's) comprehensive cancer information database. The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries come in two versions. The health professional versions have detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions have cancer information that is accurate and up to date and most versions are also available in Spanish.
PDQ is a service of the NCI. The NCI is part of the National Institutes of Health (NIH). NIH is the federal government’s center of biomedical research. The PDQ summaries are based on an independent review of the medical literature. They are not policy statements of the NCI or the NIH.
Purpose of This Summary
This PDQ cancer information summary has current information about cervical cancer prevention. It is meant to inform and help patients, families, and caregivers. It does not give formal guidelines or recommendations for making decisions about health care.
Reviewers and Updates
Editorial Boards write the PDQ cancer information summaries and keep them up to date. These Boards are made up of experts in cancer treatment and other specialties related to cancer. The summaries are reviewed regularly and changes are made when there is new information. The date on each summary ("Date Last Modified") is the date of the most recent change.
The information in this patient summary was taken from the health professional version, which is reviewed regularly and updated as needed, by the PDQ Screening and Prevention Editorial Board.
Clinical Trial Information
A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.
Clinical trials are listed in PDQ and can be found online at NCI's website. Many cancer doctors who take part in clinical trials are also listed in PDQ. For more information, call the Cancer Information Service 1-800-4-CANCER (1-800-422-6237).
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National Cancer Institute: PDQ® Cervical Cancer Prevention. Bethesda, MD: National Cancer Institute. Date last modified <MM/DD/YYYY>. Available at: http://www.cancer.gov/types/cervical/patient/cervical-prevention-pdq. Accessed <MM/DD/YYYY>.
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