What is prevention?
General Information About Cervical Cancer
Cervical Cancer Prevention
Get More Information From NCI
Changes to This Summary (08/27/2009)
Questions or Comments About This Summary
About 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:

• Changing lifestyle or eating habits.
• Avoiding things known to cause cancer.
• Taking medicines to treat a precancerous condition or to keep cancer from starting.

General Information About Cervical Cancer

Key Points for This Section

Cervical cancer is a disease in which malignant (cancer) cells form in the cervix. Screening for cervical cancer using the Pap test has decreased the number of deaths from 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).

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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 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. Dysplasia that is not treated may turn into cancer, over time. 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 Screening ¹
• Cervical Cancer Treatment ²

Screening for cervical cancer using the Pap test has decreased the number of deaths from cervical cancer.

The number of deaths from cervical cancer has decreased since widespread screening with the Pap test (Pap smear) began.

Cervical Cancer Prevention

Key Points for This Section

Avoiding risk factors and increasing protective factors may help prevent cancer. The following risk factors increase the risk of cervical cancer: HPV Infection Smoking The following risk factors may increase the risk of cervical cancer: High number of full-term pregnancies Long-term use of oral contraceptives The following protective factors may decrease the risk of cervical cancer: Preventing HPV infection Screening The effect of diet on cervical cancer risk is not known. 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 such as smoking, being overweight, and lack of exercise may help prevent certain cancers. 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 risk factors increase the risk of cervical cancer:

HPV Infection

The most common cause of cervical cancer is infection of the cervix with human papillomavirus (HPV). There are more than 80 types of human papillomavirus. About 30 types can infect the cervix and about half of them have been linked to cervical cancer. HPV infection is common but only a very small number of women infected with HPV develop cervical cancer.

HPV infections that cause cervical cancer are spread mainly through sexual contact. Women who become sexually active at a young age and who have many sexual partners are at a greater risk of HPV infection and developing cervical cancer.

Smoking

Smoking cigarettes and breathing in secondhand smoke increase the risk of cervical cancer. Among women infected with HPV, dysplasia and invasive cancer occur 2 to 3 times more often in current and former smokers. Secondhand smoke causes a smaller increase in risk.

The following risk factors may increase the risk of cervical cancer:

High number of full-term pregnancies

Women who have had 7 or more full-term pregnancies may have an increased risk of cervical cancer.

Long-term use of oral contraceptives

Women who have used oral contraceptives ("the Pill") for 5 years or more have a greater risk of cervical cancer than women who have never used oral contraceptives. The risk is higher after 10 years of use.

The following protective factors may decrease the risk of cervical cancer:

Preventing HPV infection

HPV may be prevented by the following:

• Avoiding sexual activity: HPV infection of the cervix is the most common cause of cervical cancer. Avoiding sexual activity decreases the risk of HPV infection.
• Using barrier protection or spermicidal gels: Some methods used to prevent sexually transmitted diseases (STDs) decrease the risk of HPV infection. The use of barrier methods of birth control (such as a condom or gel that kills sperm) help protect against HPV infection.
• Getting an HPV Vaccine: An HPV vaccine has been approved by the U.S. Food and Drug Administration (FDA). The HPV vaccine has been shown to prevent infection with the two types of HPV that cause most cervical cancers. The vaccine protects against infection with these types of HPV for at least five years. Studies are being done to find out if the protection lasts longer than 5 years. The vaccine does not protect women who are already infected with HPV.

Screening

Regular pelvic exams and Pap tests help find abnormal cells in the cervix before cancer develops. However, test and procedures that may be used after an abnormal pelvic exam or Pap test result have risks. For example, the treatment of low-grade lesions may affect a woman's ability to become pregnant or carry a baby to full term. (See the PDQ summary on Cervical Cancer Screening ³ for more information.)

The effect of diet on cervical cancer risk is not known.

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 Web site ⁴. Check NCI's PDQ Cancer Clinical Trials Registry for cervical cancer prevention trials ⁵ that are now accepting patients.

Get More Information From NCI

Call 1-800-4-CANCER

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There are also many other places to get materials and information about cancer treatment and services. Hospitals in your area may have information about local and regional agencies that have information on finances, getting to and from treatment, receiving care at home, and dealing with problems related to cancer treatment.

Find Publications

The NCI has booklets and other materials for patients, health professionals, and the public. These publications discuss types of cancer, methods of cancer treatment, coping with cancer, and clinical trials. Some publications provide information on tests for cancer, cancer causes and prevention, cancer statistics, and NCI research activities. NCI materials on these and other topics may be ordered online or printed directly from the NCI Publications Locator ⁸. These materials can also be ordered by telephone from the Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237).

Changes to This Summary (08/27/2009)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Images were added to this summary.

Questions or Comments About This Summary

If you have questions or comments about this summary, please send them to Cancer.gov through the Web site’s Contact Form ⁹. We can respond only to email messages written in English.

About PDQ

PDQ is a comprehensive cancer database available on NCI's Web site.

PDQ is the National Cancer Institute's (NCI's) comprehensive cancer information database. Most of the information contained in PDQ is available online at NCI's Web site ⁷. PDQ is provided as a service of the NCI. The NCI is part of the National Institutes of Health, the federal government's focal point for biomedical research.

PDQ contains cancer information summaries.

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 are available in two versions. The health professional versions provide detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions provide current and accurate cancer information.

The PDQ cancer information summaries are developed by cancer experts and reviewed regularly.

Editorial Boards made up of experts in oncology and related specialties are responsible for writing and maintaining the cancer information summaries. The summaries are reviewed regularly and changes are made as new information becomes available. The date on each summary ("Date Last Modified") indicates the time of the most recent change.

PDQ also contains information on clinical trials.

A clinical trial is a study to answer a scientific question, such as whether a certain drug or nutrient can prevent cancer. 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 and those who are at risk for cancer. During prevention clinical trials, information is collected about the effects of a new prevention method and how well it works. If a clinical trial shows that a new method is better than one currently being used, the new method may become "standard." People who are at high risk for a certain type of cancer may want to think about taking part in a clinical trial.

Listings of clinical trials are included in PDQ and are available online at NCI's Web site ¹⁰. Descriptions of the trials are available in health professional and patient versions. 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).

Glossary Terms

Not normal. An abnormal lesion or growth may be cancer, premalignant (likely to become cancer), or benign (not cancer).

Something that blocks, prevents, separates, or limits.

A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord. Also called malignancy.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

Relating to the neck, or to the neck of any organ or structure. Cervical lymph nodes are located in the neck. Cervical cancer refers to cancer of the uterine cervix, which is the lower, narrow end (the “neck”) of the uterus.

Cancer that forms in tissues of the cervix (the organ connecting the uterus and vagina). It is usually a slow-growing cancer that may not have symptoms but can be found with regular Pap tests (a procedure in which cells are scraped from the cervix and looked at under a microscope). Cervical cancer is almost always caused by human papillomavirus (HPV) infection.

The lower, narrow end of the uterus that forms a canal between the uterus and vagina.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called clinical study.

The things a person eats and drinks.

Cells that look abnormal under a microscope but are not cancer.

The developing offspring from 7 to 8 weeks after conception until birth.

An agency in the U.S. federal government whose mission is to protect public health by making sure that food, cosmetics, and nutritional supplements are safe to use and truthfully labeled. The Food and Drug Administration also makes sure that drugs, medical devices, and equipment are safe and effective, and that blood for transfusions and transplant tissue are safe. Also called FDA.

The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein.

A vaccine being studied in the prevention of human papillomavirus infection and cervical cancer. Infection with certain types of HPV increases the risk of developing cervical cancer. Also called human papillomavirus vaccine.

A type of virus that can cause abnormal tissue growth (for example, warts) and other changes to cells. Infection for a long time with certain types of human papillomavirus may cause cervical cancer. Human papillomavirus may also play a role in some other types of cancer. Also called HPV.

Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.

Cancer that has spread beyond the layer of tissue in which it developed and is growing into surrounding, healthy tissues. Also called infiltrating cancer.

An area of abnormal tissue. A lesion may be benign (not cancer) or malignant (cancer).

A term used to describe cells that look nearly normal under a microscope. These cells are less likely to grow and spread more quickly than cells in high-grade cancer or in growths that may become cancer.

Refers to the practices and procedures used for the prevention, treatment, or relief of symptoms of a diseases or abnormal conditions. This term may also refer to a legal drug used for the same purpose.

In medicine, a mineral is a nutrient that is needed in small amounts to keep the body healthy. Mineral nutrients include the elements calcium, magnesium, and iron.

A pill used to prevent pregnancy. It contains hormones that block the release of eggs from the ovaries. Most oral contraceptives include estrogen and progestin. Also called birth control pill.

A part of the body that performs a specific function. For example, the heart is an organ.

Being too heavy for one’s height. Excess body weight can come from fat, muscle, bone, and/or water retention. Being overweight does not always mean being obese.

A procedure in which cells are scraped from the cervix for examination under a microscope. It is used to detect cancer and changes that may lead to cancer. A Pap test can also show conditions, such as infection or inflammation, that are not cancer. Also called Pap smear and Papanicolaou test.

PDQ is an online database developed and maintained by the National Cancer Institute. Designed to make the most current, credible, and accurate cancer information available to health professionals and the public, PDQ contains peer-reviewed summaries on cancer treatment, screening, prevention, genetics, complementary and alternative medicine, and supportive care; a registry of cancer clinical trials from around the world; and directories of physicians, professionals who provide genetics services, and organizations that provide cancer care. Most of this information, and more specific information about PDQ, can be found on the NCI's Web site at http://www.cancer.gov/cancertopics/pdq. Also called Physician Data Query.

A physical examination in which the health care professional will feel for lumps or changes in the shape of the vagina, cervix, uterus, fallopian tubes, ovaries, and rectum. The health care professional will also use a speculum to open the vagina to look at the cervix and take samples for a Pap test. Also called internal examination.

A term used to describe a condition that may (or is likely to) become cancer. Also called premalignant.

In medicine, action taken to decrease the chance of getting a disease or condition. For example, cancer prevention includes avoiding risk factors (such as smoking, obesity, lack of exercise, and radiation exposure) and increasing protective factors (such as getting regular physical activity, staying at a healthy weight, and having a healthy diet).

Something that may decrease the chance of getting a certain disease. Some examples of protective factors for cancer are getting regular physical activity, staying at a healthy weight, and having a healthy diet.

Something that increases the chance of developing a disease. Some examples of risk factors for cancer are age, a family history of certain cancers, use of tobacco products, being exposed to radiation or certain chemicals, infection with certain viruses or bacteria, and certain genetic changes.

A person who has studied science, especially one who is active in a particular field of investigation.

Checking for disease when there are no symptoms. Since screening may find diseases at an early stage, there may be a better chance of curing the disease. Examples of cancer screening tests are the mammogram (breast), colonoscopy (colon), Pap smear (cervix), and PSA blood level and digital rectal exam (prostate). Screening can also include checking for a person’s risk of developing an inherited disease by doing a genetic test.

Smoke that comes from the burning of a tobacco product and smoke that is exhaled by smokers. Inhaling secondhand smoke is called involuntary or passive smoking. Also called environmental tobacco smoke and ETS.

The male reproductive cell, formed in the testicle. A sperm unites with an egg to form an embryo.

Adding nutrients to the diet.

A group or layer of cells that work together to perform a specific function.

The small, hollow, pear-shaped organ in a woman's pelvis. This is the organ in which a fetus develops. Also called womb.

The muscular canal extending from the uterus to the exterior of the body. Also called birth canal.

A nutrient that the body needs in small amounts to function and stay healthy. Sources of vitamins are plant and animal food products and dietary supplements. Some vitamins are made in the human body from food products. Vitamins are either fat-soluble (can dissolve in fats and oils) or water-soluble (can dissolve in water). Excess fat-soluble vitamins are stored in the body’s fatty tissue, but excess water-soluble vitamins are removed in the urine. Examples are vitamin A, vitamin C, and vitamin E.