Vaginal cancer is a malignant tumour that starts in cells of the vagina, or birth canal. Malignant means that it can spread, or metastasize, to other parts of the body. When cancer starts in vagina cells, it is called primary vaginal cancer.
The vagina is a part of a woman’s reproductive system. It is a woman’s main sex organ. The vagina is a thin-walled, muscular tube that goes from the cervix to the outside of the body. The cervix is the lower, narrow part of the uterus, or womb. The cervix opens into the vagina. Menstrual fluid passes out of the body through the vagina. During childbirth, the baby passes through the vagina.
Cells in the vagina sometimes change and no longer grow or behave normally. These changes can cause precancerous conditions. This means that the cells are not yet cancer but there is a higher chance these abnormal changes will become cancer. The most common precancerous condition of the vagina is vaginal intraepithelial neoplasia (VAIN). Most women diagnosed with VAIN are successfully treated and don’t develop cancer. But in some cases, changes to vagina cells can cause vaginal cancer.
Most often, vaginal cancer starts in flat, thin cells called squamous cells. The squamous cells make up the lining of the vagina. This type of cancer is called squamous cell carcinoma (SCC) of the vagina. Cancer can also start in the glandular cells, which make mucus. This type of cancer is called adenocarcinoma of the vagina.
Other types of vaginal cancer can also develop, but they are less common. Melanoma of the vagina starts in melanocytes, which are a type of cell that makes pigments. They are the cells that give your eyes, skin and hair their colour. Another type of cancer can start in the muscle or connective tissue cells in the vagina. This type of cancer is called sarcoma.
Other types of cancer can spread to the vagina, but this is not the same disease as primary vaginal cancer. Cancer that starts in another part of the body and spreads to the vagina is called vaginal metastasis. It is more common than primary vaginal cancer, but it isn’t treated in the same way. Most often, cancer spreads to the vagina from the cervix or vulva.