Vaginal cancer is a rare type of cancer that begins in the vagina. Cancer that begins in the vagina is called primary vaginal cancer. Cancer that develops elsewhere in the body such as the cervix, womb or ovaries and spreads to the vagina is known as secondary vaginal cancer.1
What Causes Vaginal Cancer?
The exact cause of most vaginal cancers is unknown. A number of other conditions may cause cells of the vagina to become cancerous. However, scientists have zeroed in on some factors that may cause vaginal cancer. 2
There are different kinds of risk factors. Some risk factors such as the person’s age or race can’t be changed. But others preventable factors such as smoking, alcohol consumption and diet can definitely be changed. Sometimes, a person with one or more such risk factor may never develop vaginal cancer. On the other hand, not having any risk factors doesn’t mean that a person won’t develop the disease.3 Some well-established causes of vaginal cancer are mentioned here.
Squamous cell cancer of the vagina primarily occurs in elderly women. Only 15% of cases are found in women younger than 40. Around 50% of the cases occur in women who are over 70 years old.4
DES (Diethylstilbestrol) is a hormonal drug that was administered between 1940 and 1971 to some women to prevent miscarriage. This drug can pass on from the pregnant mother to the unborn girl child. So, women, whose mothers consumed DES when pregnant with them, may develop clear-cell adenocarcinoma of the vagina or cervix. About 1 in every 1000 cases of vaginal cancer is because of this reason. So, about 99.9% of DES daughters do not develop this cancer. The use of DES during pregnancy was stopped by the FDA in 1971.5
3. Pelvic Radiotherapy
Radiotherapy performed on the pelvis for another reason may also slightly increase the risk of vaginal cancer. However, this complication is extremely rare.6
4. Vaginal Adenosis
The vagina is lined by flat cells called squamous cells. But in some cases, in about 40% of women who have already started having periods, the vagina may have one or more areas lined by glandular cells. These areas of gland cells are called adenosis. It occurs in almost all women who were exposed to DES during their mothers’ pregnancy. Though adenosis increases the risk of developing clear cell carcinoma, this cancer is quite rare.7
5. Human Papilloma Virus
Human papilloma virus (HPV) is a group of more than 150 related viruses. As some of them cause a type of growth called a papilloma, they are known as papilloma viruses. Papillomas are commonly known as warts and are not cancers. While certain types of HPV cause common warts on the hands and feet, other types may result in warts on the lips or tongue. Some types of HPV can infect the outer parts of the genital organs in both men and women. It may also occur in the anal region resulting in raised, bumpy warts. Usually, HPV 6 and HPV 11 are the main cause of genital warts. These two types are rarely associated with cancer, and hence called low-risk types of HPV. A person can contract HPV through skin-to-skin contact. One way HPV is spread is through sex, including vaginal and anal intercourse and even oral sex. Almost nine out of ten vaginal cancers and pre-cancers are linked to infection with HPV.8
6. Cervical Cancer
The occurrence of cervical cancer or pre-cancer increases a woman’s risk of vaginal squamous cell cancer. The reason for this is because cervical and vaginal cancers have similar risk factors, such as HPV infection and smoking. Sometimes, treating cervical cancer with radiation therapy is said to increase the risk of vaginal cancer. However, more research is required to acknowledge this theory.9
Smoking cigarettes increase the possibility of a woman’s risk of developing vaginal cancer by over two times.
Alcohol consumption can increase the risk of vaginal cancer. A study conducted on women who consumed alcohol found more cases of vaginal cancer than expected. Another study that also considered other risk factors found a decreased risk of vaginal cancer in women who do not consume alcohol.10
9. Gynecological Cancer History
Vaginal cancer is more likely to be diagnosed in women who have had a gynecological history of cancer including cervical cancer or early cervical cell changes that were considered to be pre-cancerous.11
HIV (human immunodeficiency virus) is the same virus that causes the deadly AIDS (Acquired Immune Deficiency Syndrome). Infection with HIV can also increase the risk of vaginal cancer.12
11. Vaginal Irritation
In some women, stretched pelvic ligaments may cause the uterus to sag into the vagina or even extend outside the vagina. One of the treatments for this condition is wearing a pessary, a device that keeps the uterus in place. Some studies show that chronic irritation of the vagina in women using a pessary may slightly increase the risk of squamous cell vaginal cancer. But this association is extremely rare, and more studies are needed to prove that pessaries actually cause vaginal cancer.13
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