Cancer of the vagina is a rare type of cancer which is more likely to develop in older women. Cancers that originate in the vagina are primary vaginal cancers, while those that spread to the vagina after originating at other locations are known as secondary vaginal cancers. Certain risk factors may be linked to the development of primary vaginal cancers, such as age, certain infections and exposure to the drug diethylstilbestrol (DES) in fetal life. It is also possible for vaginal cancer to develop in a woman who has had a hysterectomy operation.
The vagina is an elastic, muscular canal which connects the uterus and cervix to the outside of the body through the vaginal opening, which is partially closed by a thin fold of vascular tissue known as the hymen. The cervix protrudes inside and opens into the vault or upper part of the vagina. Most vaginal cancers occur in the upper third of the vagina. The vaginal wall is made up of the outer muscular layer and the inner mucosal layer. The mucosa of the vagina is lined by stratified squamous epithelium. There are no true glands in the vagina but the glandular or secretory cells in the lining of the vagina are responsible for producing and releasing secretions such as mucus.
Vaginal cancer usually begins on the surface of the vaginal epithelium. With time, as it invades the deeper layers of the vagina and the surrounding tissue, the bladder in front and the rectum behind may be affected by direct spread of the cancer. In later stages of the disease, spread to distant sites such as the lungs, liver, bone, and skin may occur through the blood and lymphatic vessels.
More than 95% of vaginal cancers are squamous cell carcinomas, which are slow-growing cancers that originate in the squamous cells of the vaginal epithelium. These develop most often in women over the age of 60. Almost all other vaginal cancers are adenocarcinomas, which originate in the glandular cells. They occur more often in younger women and are likely to spread more rapidly than squamous cell carcinomas. The other rarer types of vaginal cancer are clear cell carcinoma (seen almost exclusively in women who have been exposed to DES while in their mother’s womb), melanoma, and sarcoma.
The exact cause of vaginal cancer is not known. Women who may be more at risk are those over 60, infection with HPV, exposure to DES, and previous history of cervical cancer, vulvar cancer or ovarian cancer. Chemotherapy, radiation therapy to the pelvic area, immunosuppression therapy, and HIV/AIDS infection have been linked with development of vaginal cancer. Having multiple sexual partners, smoking, long-term use of vaginal pessary, and procidentia or complete uterine prolapse may be considered as other risk factors.
The diagnosis of vaginal cancer is often missed or delayed since there may not be any symptoms in the early stages. Also, some of the symptoms, when present, may be common to a number of other conditions. Quite often, vaginal cancer is detected during a routine pelvic examination or Pap test.
Abnormal vaginal bleeding is the most common symptom, of which postmenopausal bleeding is a common feature since vaginal cancer occurs most frequently in women over 60. Intermenstrual bleeding, post-coital bleeding, heavy menstrual periods, or vaginal bleeding unrelated to menstruation may be the other presenting complaints.
Other likely symptoms are abnormal vaginal discharge, painful intercourse, pelvic pain, or presence of a vaginal lump. Involvement of the bladder may give rise to urinary symptoms such as painful urination or blood in the urine, while rectal involvement may cause painful defecation and constipation.
The outlook depends upon the type of cancer, age and health condition of the patient, and the stage and grade of the cancer when detected. Cancers detected while still confined to the vagina have better prognosis than those that have spread elsewhere.
