Causes, Risk Factors, and Prevention of Vaginal Cancer

Squamous cell cancer of the vagina occurs mainly in older women. It can happen at any age, but very few cases are found in younger women. Almost half of cases occur in women who are 70 years old or older.

Normally, the vagina is lined by flat cells called squamous cells. In about 40% of women who have already started having periods, the vagina might have one or more areas lined by glandular cells instead. These areas are called adenosis.

In some cases, adenosis is caused by exposure to medications before birth, such as DES. In other cases, the cause of adenosis is not known. Having vaginal adenosis increases the risk of vaginal adenocarcinomas.

HPV is a group of related viruses that are grouped based on differences in their DNA. Each HPV type is identified by a number.

HPV is found in most cases of vaginal cancer. HPV 16 and HPV 18 are the most common cancer-causing types. These types are known as high-risk types of HPV. Infection with a high-risk HPV might not have any visible signs until precancerous changes or cancer develops.

See HPV for more information.

Infection with HIV, the virus that causes AIDS, increases the risk of vaginal cancer.

This is because HIV can weaken the immune system. If people with HIV are also infected with HPV, the immune system can have a hard time getting rid of it. This puts the person at higher risk for developing HPV-associated vaginal precancer (VaIN) or cancer.

See HIV Infection and Cancer for more information.

DES is a drug that was given to pregnant women to prevent miscarriage. It was used from the 1940s until 1971, when the FDA stopped its use.

When taken by a pregnant mother, DES can affect the development of the female reproductive organs in her child and leave glandular cells in the vagina (adenosis). It increases the risk of a specific type of vaginal cancer called clear cell adenocarcinoma.

Learn more in DES Exposure: Questions and Answers.

Medicines that weaken the immune system, such as those used after a transplant, can increase the risk of vaginal cancer. This is because these medications can make it harder for the body to fight and get rid of viruses such as HPV.

Smoking cigarettes more than doubles a woman’s risk of getting vaginal cancer.

Drinking alcohol might increase the risk of vaginal cancer. Some studies of women who drink alcohol found more cases of vaginal cancer than expected. But these studies didn’t look at other factors that can change cancer risk, such as smoking and HPV infection. A more recent study that did consider these other risk factors found a decreased risk of vaginal cancer in women who did not drink alcohol at all.

Sometimes, stretched pelvic ligaments let the uterus sag into the vagina or even extend outside the vagina. This is called uterine prolapse. It can be treated with surgery or by wearing a pessary, a device to keep the uterus in place.

Some studies suggest that long-term (chronic) irritation of the vagina in women using a pessary might slightly increase the risk of squamous cell vaginal cancer. But this is very rare, and no studies have clearly proven that pessaries cause vaginal cancer.

Preventing certain sexually transmitted infections (STIs) through safe sex practices can lower your risk of vaginal cancer. Two STIs that can increase your risk of vaginal cancer are:

• HPV (human papillomavirus)
• HIV (human immunodeficiency virus)

HPV is very common and passes from one person to another through direct contact with an infected area of the body, such as through sexual contact.

HIV passes from one person to another through contact with body fluids.

If you are sexually active, there are a few ways you can reduce your risk of STIs.

• Avoid high-risk sexual behaviors: These include having multiple sexual partners, unprotected sex, sex with a partner with a known STI, or having sex when you have open wounds, such as a genital or oral ulcer.
• Condoms: Using condoms can help you avoid contact with infected areas of the body and bodily fluids and reduce the risk of infection.
• Vaccination: A vaccine has been developed to protect against HPV infection.
• PrEP: PrEP (pre-exposure prophylaxis) medicine can help lower the risk of getting HIV from an infected partner before sex.
• PEP: PEP (post-exposure prophylaxis) medicine can help lower the risk of getting HIV from an infected partner after sex.

HPV vaccines can protect against infection with certain types of HPV. These vaccines can only be used to prevent HPV infection and can’t help treat an existing infection. To work best, the vaccines should be given before a person is exposed to HPV, such as through sexual activity. These vaccines are approved to help prevent vaginal cancers and precancers (VaIN). They are also approved to help prevent 5 other cancers and genital warts.

For more information about HPV and HPV vaccines, see HPV (Human Papillomavirus).

Smoking can increase vaginal cancer risk. People who don’t smoke are less likely to develop vaginal cancer and a number of other cancers, such as those of the lungs, mouth, throat, bladder, kidneys, and several other organs.

Most vaginal squamous cell cancers start out as precancerous changes, called vaginal intraepithelial neoplasia (VaIN). VaIN might be present for years before turning into cancer.

Screening for cervical cancer with a Pap test or HPV test can sometimes find precancers or related problems in the vagina. If a precancer is found, it can be treated before cancer forms.