Cervical Cancer Prevention (PDQ®)
Last modified: 2016-04-08
Last downloaded: 2017-02-20
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:
- Changing lifestyle or eating habits.
- Avoiding things known to cause cancer.
- Taking medicines to treat a precancerouscondition or to keep cancer from starting.
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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).Anatomy of the female reproductive system. The organs in the female reproductive system include the uterus, ovaries, fallopian tubes, cervix, and vagina. The uterus has a muscular outer layer called the myometrium and an inner lining called the endometrium.
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 cervicaltissue. When cells change from being normal cells to abnormal cells, it is called dysplasia. The abnormal cervical cells may go away without treatment, stay the same, or turn into cancer cells over many years.
See the following PDQ summaries for more information about cervical cancer:
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Cervical Cancer Prevention
- Avoiding risk factors and increasing protective factors may help prevent cancer.
- The following are risk factors for cervical cancer:
- In women who are infected with HPV, other risk factors add to the increased risk of cervical cancer:
- The following increase the risk of HPV infection:
- The following protective factors decrease the risk of cervical cancer:
- 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 cancerrisk factors may help prevent certain cancers. Risk factors include smoking, being overweight, and not getting enough exercise. Increasing protective factors such as quitting smoking 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:
Cervical cancer is almost always caused by human papillomavirus (HPV) infection that is 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.
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 who are infected with HPV, other risk factors add to the increased risk of cervical cancer:
Among women who are infected with HPV, those who have had 7 or more full-term pregnancies have an increased risk of cervical cancer.
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.
Among women who are infected with HPV, those 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. Current and former smokers have 2 to 3 times the risk of cervical dysplasia and invasive cervical cancer.
The following increase the risk of HPV infection:
Having a weakened immune system caused by immunosuppression increases the risk of HPV infection and cervical cancer. Immunosuppression weakens the body’s ability to fight infection and other diseases.
Immunosuppression can be caused by these and other conditions:
- Human immunodeficiency virus (HIV). This virus causes AIDS and weakens the body's immune system.
- Medicine given 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.
Women who are infected with the HIV virus or who take medicine to prevent organ rejection after transplant are less able to fight HPV infection and are at increased risk of cervical cancer.
The risk of HPV infection is higher in women who become sexually active before age 18 and in women who have had 6 or more sexual partners.
The following protective factors decrease the risk of cervical cancer:
Nearly all cases of cervical cancer are caused by HPV infection, which is spread through sexual activity. Women who are not sexually active have almost no risk of cervical cancer.
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.
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 preventionclinical 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.
Back to Top Source: The National Cancer Institute's Physician Data Query (PDQ®) Cancer Information Summaries (http://www.cancer.gov/cancertopics/pdq)