What are the risk factors for cancer of the cervix?
A risk factor is anything that affects a person's chance of getting a disease like cancer. 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 screened for cervical cancer.
Cervical cancer risk factors include:
Human papilloma virus (HPV) infection
The most important risk factor for cervical cancer is infection with a virus known as HPV (human papilloma virus). HPV is really a group of more than 150 related viruses that can infect cells on the surface of the skin, and the cells lining the genitals, anus, mouth, and throat.
Some types of HPV cause warts, with certain types causing genital warts. The types of HPV that cause genital warts are called low risk HPVs because they are rarely linked to cancer. Other types are strongly linked to certain cancers, including cancer of the cervix. In fact, doctors believe that a woman must be infected by HPV before she develops cervical cancer. The kinds that tend to cause cancer are called high-risk HPVs.
HPV is passed from one person to another by skin-to-skin contact such as during vaginal, anal, or oral sex. But sex isn't the only way to spread HPV. All that is needed is skin-to-skin contact with a part of the body infected with 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 certain cancers, including cervical cancer.
The Pap test can find cell changes that point to HPV infection. Other tests look for the infections themselves by finding genes (DNA) from HPV in the cells. For some women, the HPV test is used along with the Pap test as a part of screening. There is no cure for HPV, but 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 start. Not all of these factors are known, but some are listed below.
Other risk factors
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. Tobacco by-products have been found in the cervical mucus of women who smoke. Smoking also makes the immune system less able to fight HPV infections.
Weakened immune system
HIV (human immunodeficiency virus) is the virus that causes AIDS − it is not the same as HPV. Women infected with HIV are more likely to get cancer of the cervix. Having HIV seems to make a woman's immune system less able to fight both HPV and early cancers.
Another group of women at risk of cervical cancer are women getting drugs to suppress their immune response. This would include those being treated for an autoimmune disease or those who have had an organ transplant.
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 unless she is tested for chlamydia when she gets her pelvic exam. Some studies suggest that women who have a past or current infection have a greater risk for cancer of the cervix. Long-term infection can cause other serious problems, too.
Women with diets low in fruits and vegetables may have an increased risk for cervical cancer.
Overweight women are more likely to develop adenocarcinoma of the cervix.
Birth control pills
Long-term use of birth control pills increases the risk of cervical cancer. Research suggests that the risk 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.
A recent study found that women who had ever used an IUD (intrauterine device) had a lower risk of cervical cancer. The effect on risk was seen even in women who had an IUD for less than a year, and the protective effect remained after the IUDs were removed. But IUDs do have some risks. A woman thinking of using an IUD should first discuss the pros and cons with her doctor.
Having many pregnancies
Women 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.
Poor women have a greater risk for cancer of the cervix. This may be because they cannot afford good health care, such as regular Pap tests.
DES is a hormone drug that was given between 1940 and 1971 to 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.
You can learn more about DES in our separate document called DES Exposure: Questions and Answers. You can read it on our Web site, or call to have a free copy sent to you.
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: 04/24/2013
Last Revised: 04/24/2013