Incidence
Primary vaginal cancer represents 1-2% of malignancies of the female genital tract with average age of diagnosis at 60 years. The majority of vaginal neoplasms are metastatic lesions from other primary sources.
Risk Factors
Postulated risk factors include low socioeconomic status, history of HPV infection, chronic vaginal irritation, prior abnormal PAP with CIN, prior hysterectomy (59% of patients with primary vaginal cancer), prior treatment for cervical cancer.
A subset of patients of special note are those who have had in-utero exposure to DES (DES was used from 1940 to 1971) during the first half of pregnancy. The risk of an exposed fetus to develop clear cell carcinoma of the vagina later in life is 1:1000 with peak age at diagnosis being 19 years.
Pathology
The majority of primary vaginal cancers are of the squamous cell variety (85%) with adenocarcinoma representing the second most common variety (9%) and sarcoma, melanoma and less common types comprising the remainder.
Routes of Spread
1. Direct extension to adjacent structures
2. Lymphatic dissemination: Lesions of the upper 2/3 of the vagina metastasize directly to the pelvic lymph nodes. Lesions of the lower 1/3 of the vagina metastasize first to the inguino-femoral nodes and secondarily to the pelvic nodes.
3. Hematogenous dissemination: This represents a late occurence as the disease is confined primarily to the pelvis in the majority of cases.
Clinical Features
Symptoms: Painless vaginal bleeding is the most common symptom followed by vaginal discharge. Other less common presenting features include bladder symptoms, tenesmus and pelvic pain (usually indicative of locally advanced disease).
Physical Findings: Lesions are primarily found in the upper 1/3 of the vagina, usually on the posterior wall. The appearance of lesions is variable with a range from exophytic to endophytic. Surface ulceration is usually not present except in advance cases. Visualization of the lesion identified on cytology may require colposcopy.
Pretreatment Work-Up
1. Colposcopy (unless lesion visible)
2. CXR
3. CT or CT/PET imaging
Staging
Stage 0: Carcinoma in situ, intraepithelial carcinoma
Stage I: Carcinoma limited to the vaginal wall.
Stage II: The carcinoma has involved the subvaginal tissue but has not extended to the pelvic wall.
Stage III: The carcinoma has extended to the pelvic wall.
Stage IV: The carcinoma has extended beyond the true pelvis or has involved the mucosa of the bladder or rectum.
IV A- Spread of growth to adjacent organs
IV B- Spread to distant organs
Treatment
Stage 0: Surgical excision, laser ablation and in some cases 5-FU application
Stage I: These may be broken down into two treatment groups:
1. Lesions of the upper vaginal fornices may be treated surgically with radical hysterectomy (upper vaginectomy) and pelvic lymphadenectomy. Another alternative is radiotherapy alone.
2. All lesions of stage one, including those above, may be treated with radiotherapy usually in the form of an intracavitary cylinder.
Stage II, III, and IV: Treatment consists of external beam radiotherapy and intracavitary and/or interstitial therapy and if the lower 1/3 of the vagina is involved the groin should also be treated.
Recurrent Disease: Treatment is variable and depends on the extent of recurrence and includes wide local excision, partial vaginectomy, and exenteration. For distant metastatic disease, chemotherapy is an option, but because of the rarity of this tumor its role is unclear.
Prognostic Factors
The most important prognostic factor is stage of disease.
Survival
Stage I- 80%
Stage II- 45%
Stage III- 35%
Stage IV- 10%
Recommended Follow-Up
Physical examination every 3 months for years 1-2, every 6 months for years 3, 4 and 5, and annually thereafter.