Cancer starts when cells in the body begin to grow out of control. Cells in nearly any part of the body can become cancer, and can spread to other areas of the body. Vaginal Cancer starts in the vagina. There are many different types of vaginal cancer, but the most common is called squamous cell carcinoma. It starts in the lining of the vagina.
The vagina starts at the cervix (the lower part of the uterus) and opens at the vulva (the external female genitals). The vagina is usually collapsed with its walls touching each other. The vaginal walls have many folds that help the vagina open and expand during sex or the birth of a baby.
Several different types of cells and tissues are found in the vagina:
The lining of the vagina has a layer of flat cells called squamous cells. This layer of cells is also called epithelium or epithelial lining because squamous cells are a type of epithelial cell. The vaginal wall underneath the epithelium is made up of connective tissue, muscle, lymph vessels, and nerves. Glands near the opening of the vagina make mucus to keep the vaginal lining moist.
VAIN (vaginal pre-cancer)
A pre-cancer is a condition where some cells look abnormal. These cell changes are not cancer, but could become cancer over time. Vaginal intraepithelial neoplasia or VAIN means that the changed cells are only found in the innermost surface layer of the vagina. VAIN is more common in women who have had their uterus removed (hysterectomy) and in those who were treated for cervical cancer or pre-cancer in the past.
There are 3 types of VAIN: VAIN1, VAIN2, and VAIN3. VAIN3 is the closest to a true cancer. In the past, the term dysplasia was used instead of VAIN. The types of dysplasia were referred to as mild, moderate, and severe, based on how close it was to a true cancer. This term is used much less now. Low-grade VAIN (VAIN1) will sometimes go away on its own, but VAIN can sometimes lead to cancer if not treated. Higher-grade VAIN (VAIN2 or VAIN3) is usually treated right away.
Types of vaginal cancer
Though it’s quite rare, there are many types of vaginal cancer. Each type forms from a different type of cell in the vagina.
Squamous cell carcinoma
Nearly 9 out of 10 cases of vaginal cancer are squamous cell carcinomas. These cancers start in the squamous cells that make up the epithelial lining of the vagina. They’re most common in the upper part of the vagina near the cervix. If not treated, they can grow deeper into and, over time, through the vaginal wall and spread to nearby tissues. They can also spread to other parts of the body, most often the lungs, but also the liver and bones. Squamous cell cancers of the vagina often develop slowly. First, some of the normal cells of the vagina get pre-cancerous changes (VAIN). Then some of the pre-cancer cells turn into cancer cells. This process can take many years.
Cancers that start in gland cells are called adenocarcinomas. About 1 out of 10 cases of vaginal cancer are adenocarcinomas. The most common type of vaginal adenocarcinoma is found in women older than 50. Another type, called clear cell adenocarcinoma, is more common in young women who were exposed to diethylstilbestrol(DES) in utero (when they were in their mother’s womb).
Melanomas start in pigment-producing cells that give skin its color. These cancers usually are found on sun-exposed parts of the skin, but they can also form in the vagina or other internal organs. Fewer than 3 of every 100 cases of vaginal cancer are melanomas. Melanoma tends to affect the lower or outer portion of the vagina. The tumors vary greatly in size, color, and growth pattern
Sarcomas are cancers that start in the cells of bones, muscles, or connective tissue. Fewer that 3 out of every 100 cases of vaginal cancer are sarcomas. These cancers form deep in the wall of the vagina, not on its surface. There are several types of sarcomas. Rhabdomyosarcoma is the most common type of sarcoma that affects the vagina. It’s most often found in children and is rare in adults. A sarcoma called leiomyosarcoma is seen more often in adults. It tends to occur in women older than 50.
Cancers that spread to the vagina
Cancers that start in the vagina are much less common than cancers that start in other organs (such as the cervix, uterus, rectum, or bladder) and then spread to the vagina. These cancers are named after the place where they started. If a cancer involves both the cervix and vagina, it is considered a cervical cancer. Likewise, if the cancer involves both the vulva and the vagina, it’s considered a vulvar cancer.