Risk factors for cervical cancer

A risk factor is anything that affects a person's chance of getting a disease. Some risk factors, such as smoking, can be controlled. Others, like a person's age or race, can't be changed. But having a risk factor, or even several, does not mean that you will get the disease. Women without any risk factors rarely get cervical cancer. On the other hand, while these risk factors increase the odds of getting cervical cancer, many women with these risks do not get this disease.

In looking at risk factors, it helps to focus on those that can be changed. Still, those that can't be changed also serve to remind women about the importance of getting a Pap test. These risk factors increase a woman's chance of getting cervical cancer:

Human papilloma virus (HPV) infection

For cervical cancer, the most important risk factor is infection with a virus known as HPV (human papilloma virus). HPV is really a group of more than 100 related viruses that can infect cells on the surface of the skin. Some types of HPV cause genital warts. Other types cause cancer of the cervix. The kinds that cause cancer are called "high-risk" HPVs. HPV is passed from one person to another by skin-to-skin contact such as vaginal, anal, or oral sex. But sex isn't the only way to spread HPV from one person to person. All that is needed is for there to be skin-to-skin contact with an area of the body infected with HPV.

Having unprotected sex, especially at a young age, makes HPV infection more likely. Also, women who have many sex partners (or who have sex with men who have had many partners) have a greater chance of getting HPV.

Many women may have HPV, but very few of these women will ever get cervical cancer. In most cases the body fights off the virus, and the infection goes away without any treatment. But in some women, the infection lasts and can cause cervical cancer. HPV is mainly found in young women and is less common in women over 30. We don't know why this is so. Condoms (rubbers) may help protect against HPV when they are used correctly. But HPV can still be passed from one person to another by skin-to-skin contact with an HPV-infected area of the body that is not covered by a condom. Still, it is important to use condoms because they can help protect against AIDS and other sexual diseases, too.

The Pap test, and some newer tests, can find changes that point to HPV infection. While there is no cure for HPV, the abnormal cell growth they cause can be treated. Vaccines have been made that will prevent infection with some types of HPV. Please see the section "Can cancer of the cervix be prevented?" to learn more about the HPV vaccines.

Even though HPV is an important risk factor for cervical cancer, most women with this infection do not get cervical cancer. Doctors believe other factors must come into play for this cancer to grow. Some of these factors are listed below.

Other risk factors

Smoking: Women who smoke are about twice as likely to get cervical cancer as those who don't. Smoking puts many chemicals that cause cancer into the lungs. These harmful substances are carried in the bloodstream throughout the body to other organs, too. Tobacco by-products have been found in the cervical mucus of women who smoke.

HIV infection: HIV (human immunodeficiency virus) is the virus that causes AIDS -- it is not the same as HPV. It can also be a risk factor for cancer of the cervix. Having HIV seems to make a woman's immune system less able to fight both HPV and early cancers.

Chlamydia infection: This is a common kind of bacteria that can infect women's sex organs. It is spread during sex. A woman may not know that she is infected at all unless she is tested for chlamydia when she gets her pelvic exam. Some studies suggest that women who have a past or current infection are at greater risk for cancer of the cervix. Long-term infection can cause other serious problems, too.

Diet: What you eat can play a part as well. Diets low in fruits and vegetables are linked to an increased risk of cervical cancer. Also, women who are overweight are at a higher risk.

Birth control pills: Long-term use of birth control pills increases the risk of this cancer. Research suggests that the risk of cervical cancer goes up the longer a woman takes "the pill," but the risk goes back down again after she stops. You should talk to your doctor about the pros and cons of birth control pills in your case.

Having many pregnancies: Woman who have had 3 or more full-term pregnancies have an increased risk of this cancer. No one really knows why this is true.

Young age at the time of first full-term pregnancy: Women who were younger than 17 years when they had their first full-term pregnancy are almost 2 times more likely to get cervical cancer later in life than women who waited to get pregnant until they were 25 years or older.

Low income: Poor women are at greater risk for cancer of the cervix. This may be because they cannot afford good health care, such as regular Pap tests.

DES (diethylstilbestrol): DES is a hormone drug that was used between 1940 and 1971 for some women who were in danger of miscarriages. The daughters of women who took this drug while they were pregnant with them have a slightly higher risk of cancer of the vagina and cervix.

Family history: Cervical cancer may run in some families. If your mother or sister had cervical cancer, your chances of getting the disease are 2 to 3 times higher than if no one in the family had it. This could be because these women are less able to fight off HPV than other women.

Last Medical Review: 09/24/2009
Last Revised: 09/24/2009