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.
Infection with human papillomavirus (HPV) is a risk factor for vaginal cancer. In women, HPV infections occur mainly at younger ages and are less common in women over 30. The reason for this is not clear. Most of these infections in young women disappear, but 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 a genital HPV infection, such as:
Delaying sex until you are older can help you avoid HPV. It also helps if you limit your number of sex partners and avoid having sex with someone who has had many other sex partners. Remember that HPV can be present for years without causing any symptoms. It does not always cause warts or any other symptoms. Someone can have the virus and pass it on without knowing it.
The 2 main factors influencing the risk of genital HPV infection in men are circumcision and the number of sexual partners. Men who are circumcised (have had the foreskin of the penis removed) have a lower chance of becoming and staying infected with HPV.
Men who have not been circumcised are more likely to be infected with HPV and pass it on to their partners. The reasons for this are unclear. It may be that the skin on the glans of the penis goes through changes that make it more resistant to HPV infection. Another theory is that the surface of the foreskin (which is removed by circumcision) is more easily infected by HPV. Still, circumcision does not completely protect against HPV infection men who are circumcised can still get HPV and pass it on to their partners.
The risk of being infected with HPV is also strongly linked to having many sexual partners (over a man's lifetime).
Condoms ("rubbers") provide some protection against HPV. One study found that when condoms are used correctly every time sex occurs, they can lower the HPV infection rate by about 70%. Condoms cannot protect completely because they don't cover every possible HPV-infected area of the body, such as skin on 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. Condoms (when used by the male partner) also seem to help genital HPV infections clear (go away) faster in both women and men.
Vaccines have been developed to help prevent infection with some types of HPV. Right now, 2 HPV vaccines have been approved for use in the United States by the Food and Drug Administration (FDA), Gardasil® and Cervarix®. Both vaccines protect against HPV types 16 and 18, the types that cause most cases of cervical cancer. These 2 types of HPV also cause many cases of vulvar and vaginal cancer. Gardasil also protects against HPV types 6 and 11, the types that cause most cases of genital warts. Both Gardasil and Cervarix work best if given to females before they become sexually active. Both vaccines lower the risk of cervical cancers and pre-cancers, but in studies Gardasil has also been shown to prevent vaginal and vulvar cancers and pre-cancers caused by HPV 16 and 18. More HPV vaccines are being developed and tested.
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.
Most vaginal squamous cell cancers are believed to start out as pre-cancerous changes, called vaginal intraepithelial neoplasia or 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 these guidelines for the early detection of cervical cancer:
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, for the Pap test, 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). 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 do 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. In women whose cervix has been removed by surgery, Pap test samples are 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.
There are 2 main options, conventional cytology and liquid-based cytology, for preparing cell samples for the Pap test 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.