The best way to reduce the risk of vaginal cancer is to avoid known risk factors and to find and treat any vaginal pre-cancers. But since many women with vaginal cancer have no known risk factors, it is not possible to completely prevent this disease.

Avoiding risk factors

HPV infection

Infection with human papillomavirus (HPV) is risk factor for vaginal cancer. HPV infections occur mainly in young women and are less common in women over 30. The reason for this is not entirely clear. But most of these infections in young women disappear, in some cases the HPV DNA remains inside cells of a woman's cervix and vagina. This can lead to pre-cancerous changes and even to cancer many years later.

Certain types of sexual behavior increase a woman's risk of getting HPV infection, such as:

• having sex at an early age
• having many sex partners
• having a partner who has had many sex partners
• having sex with uncircumcised males

Delaying sex until you are older can help you avoid HPV. It also helps to limit your number of sex partners and to avoid having sex with someone who has had many other sex partners. Uncircumcised men seem to be more likely to have the virus and be able to pass it on to someone else. Remember that HPV can be present for years with no symptoms -- it does not always cause warts or any other symptoms. Someone can have the virus and pass it on without knowing it.

Condoms provide some protection against HPV. One study found that when condoms are used correctly they can lower the HPV infection rate by about 70% -- if they are used every time sex occurs. Condoms cannot protect completely because they don't cover every possible HPV-infected area of the body, such as skin of the genital or anal area. Still, condoms do provide some protection against HPV, and they also protect against HIV and some other sexually transmitted diseases.

Vaccines have been developed to help prevent infection with some types of HPV. Right now, there is an HPV vaccine that has been approved for use in the United States by the Food and Drug Administration (FDA). This vaccine is called Gardasil^®, and it protects against HPV types 6, 11, 16, and 18. Gardasil is recommended for use in young women before they start having sex. This vaccine was designed to lower the risk of cervical cancers and pre-cancers, but it also prevents vulvar and vaginal cancers (and pre-cancers) caused by HPV 16 and 18. Other HPV vaccines are being developed and tested.

Smoking

Not smoking is another way to lower vaginal cancer risk. Women who don't smoke are also less likely to develop a number of other cancers, such as those of the lungs, mouth, throat, bladder, kidneys, and several other organs.

Detecting pre-cancerous conditions

Most vaginal squamous cell cancers are believed to start out as pre-cancerous changes, called vaginal intraepithelial neoplasia (VAIN). VAIN may be present for years before turning into a true (invasive) cancer. These pre-cancers can be found with the same Pap test that is used to screen for cervical cancer and pre-cancer. If a pre-cancer is found, it can be treated, stopping cancer before it really starts.

The American Cancer Society recommends:

All women should begin cervical cancer screening about 3 years after they start having sex (vaginal intercourse), A woman who waits until she is over 18 to have sex should start screening no later than age 21. Screening should be done every year with the regular Pap test or every 2 years using the newer liquid-based Pap test.

Beginning at age 30, women who have had 3 normal Pap test results in a row may be screened less often -- every 2 to 3 years. Testing can be with either the conventional (regular) or liquid-based Pap test. Some women should continue getting tested yearly -- such as those who were exposed to diethylstilbestrol (DES) before birth, and those with a weakened immune system (from HIV infection, an organ transplant, chemotherapy, or chronic steroid use)..

Another reasonable option for women over 30 is to get screened every 3 years (but not more frequently) with either the conventional or liquid-based Pap test, plus the HPV DNA test.

Women 70 years of age or older who have had 3 or more normal Pap tests in a row and no abnormal Pap test results in the last 10 years may choose to stop having cervical cancer screening. Women with a history of cervical cancer, DES exposure before birth, HIV infection or a weakened immune system should continue to have screening as long as they are in good health.

Women who have had a total hysterectomy (the uterus and cervix are removed) may also choose to stop having cervical cancer screening, unless the surgery was done as a treatment for cervical cancer or pre-cancer. Women who have had a hysterectomy without removing the cervix should continue to follow the guidelines above.

How Pap tests and pelvic examinations are done

First, the skin of the outer lips (labia majora) and inner lips (labia minora) is examined for any visible abnormalities. Then the health care professional inserts a speculum, a metal or plastic instrument that keeps the vagina open so that the cervix and vagina can be seen clearly. Next, a sample of cells and mucus is lightly scraped from the exocervix (part next to the vagina) using a spatula. A small brush or a cotton-tipped swab is used to sample the endocervix (the inside part of the cervix that is closest to the body of the uterus). There are 2 main options, conventional cytology and liquid-based cytology, for preparing the cell samples so that they can be examined under a microscope in the laboratory.

Conventional cytology

The first option is to smear the sample directly onto a glass microscope slide, which is then sent to the laboratory. For about 50 years, all cervical cytology (Pap test) samples were handled this way. This method works quite well and is relatively inexpensive, but it does have some drawbacks. One problem with this method is that the cells smeared onto the slide are sometimes piled up on each other, making it hard to see the cells at the bottom of the pile. Also, white blood cells (pus), increased mucus, yeast cells, or bacteria from infection or inflammation can hide the cervical/vaginal cells. Another problem with direct smears is that if the slides are not treated (with a preservative) right away, the cells can get dried out. This can make it difficult to tell if there is something wrong with the cells. The Pap test may need to be repeated if the cells cannot be seen well (due to any of the above problems).

Liquid-based cytology

Another method is to put the sample of cells directly into a special preservative liquid (instead of putting them on a slide directly). This is then sent to the lab. Technicians use special lab instruments that spread some of the cells in the liquid onto glass slides to look at under the microscope. This method is called liquid-based cytology, or a liquid-based Pap test. The liquid helps remove some of the mucus, bacteria, yeast, and pus cells in a sample. It also allows the cells to be spread more evenly on the slide and keeps them from drying out and becoming distorted. Cells kept in the liquid can also be tested for HPV. Using liquid-based testing reduces the chance that the Pap test will need to be repeated, but it does not seem to find more pre-cancers than a regular Pap test. The liquid based test is also more likely to find cell changes that are not pre-cancerous but that will need to be checked out further -- leading to unnecessary tests. This newer method is more expensive than a usual Pap test.

No matter which way is used, the slides are looked at by specially trained technologists (cytotechnologists) and doctors (pathologists). Another way to improve the Pap test by using computerized instruments that can spot abnormal cells in Pap smears. A machine that can read Pap tests has been approved by the US Food and Drug Administration (FDA) to read Pap tests first (instead of them being examined by a technologist). It is also approved by the FDA for rechecking Pap test results that were read as normal by technologists. Any smear identified as abnormal by the machine would then be reviewed by a doctor or a technologist.

After the Pap test, the speculum is removed. The doctor then will check the organs of the pelvis by inserting 1 or 2 gloved fingers of one hand into the vagina while he or she palpates (feels) the lower abdomen, just above the pubic bone, with the other. The doctor may include a rectal exam at this time also.

Vaginal intraepithelial neoplasia (VAIN; pre-cancer of the vagina) usually can't be seen during a routine exam of the vagina. This is why the Pap test is so important. Because cervical cancer is much more common than vaginal cancer, Pap test samples are scraped or brushed from the cervix. However, some cells of the vaginal lining are usually also picked up at the same time. That allows many cases of VAIN to be found in women whose vaginal lining is not intentionally scraped. Of course, in women whose cervix has been removed by surgery, Pap test samples are purposely taken from the lining of the upper vagina.

Many women with VAIN may also have a pre-cancer of the cervix (known as cervical intraepithelial neoplasia or CIN). If abnormal cells are seen on a Pap test, the next step is a procedure called colposcopy, in which the cervix, the vagina, and at times the vulva are examined with a special instrument called a colposcope.

Last Medical Review: 12/30/2008
Last Revised: 09/14/2009