The vagina is a muscular tube, which can stretch to allow childbirth. It is lined by a thick membrane which is also covered by squamous epithelium.
Primary cancer of the vagina accounts for only about 2% of gynaecological cancers, although the vagina is more commonly involved with secondary spread of cancer from the adjacent cervix or vulva. Most women with vaginal cancer are postmenopausal and 95% of vaginal cancers are squamous cell carcinomas. Many of these cancers are caused by HPV infection and about 30% of women with vaginal cancer will have a prior history of cervical precancer [CIN] or cancer.
A woman with early vaginal cancer may have no symptoms and her cancer may only be detected by Pap testing. As the cancer grows, it will cause abnormal vaginal bleeding and discharge. This may include bleeding after intercourse (post-coital bleeding). If it continues to grow, it may invade into the bladder or rectum and cause pain or urgency when urinating, or pain when passing a bowel motion. It may also spread to lymph nodes in the pelvis or groin and cause pain.
Diagnosis requires a biopsy, which can usually be done in the clinic under local anaesthesia, but may need to be performed under anaesthesia (Examination under Anaesthesia or EUA). An EUA will also allow an assessment of the local extent of the cancer, including looking into the bladder (cystoscopy) and into the rectum (proctoscopy). Imaging will usually include a CT or MRI scan.
- Stage 1 means the cancer is confined to the vaginal wall.
- Stage 2 means the cancer has extended outside the vaginal wall, but not to the pelvic sidewall.
- Stage 3 means that the cancer has extended out to the pelvic sidewall.
- Stage 4 means the cancer has invaded the bladder or rectum (stage 4A) or spread beyond the pelvis, e.g. to the lungs (4B).
The close proximity of the bladder and rectum almost invariably makes it impossible to treat a woman’s vaginal cancer surgically. She is therefore treated with chemotherapy and radiation [chemoradiation]. She will typically receive external beam pelvic radiation daily Monday-Friday for 5-6 weeks and cisplatin weekly during this treatment. The cisplatin sensitises the cancer cells, making the radiation more effective. At the completion of the external radiation, she will be treated with brachytherapy.
The overall 5-year survival rate for vaginal cancer is about 50%, but if diagnosed while stage I, the survival is about 90%.