Causes and Risk Factors

The pathogenesis of vaginal cancer can be divided into human papillomavirus (HPV) induced and non-HPV induced. Just as it is found in cervical cancer, the HPV 16 virus strain accounts for a majority of HPV-positive patients. Younger age at first intercourse, multiple sexual partners, persistent HPV infection, tobacco use, and immunosuppression are some of the risk factors for vaginal cancer which is similar to those of cervical cancer(4)

Symptoms

The commonest symptom of vaginal cancer is abnormal vaginal bleeding. Other symptoms include watery, malodourous or blood-stained vaginal discharge and vaginal mass(3). Urinary or gastrointestinal symptoms indicate a local extension of the tumour while pelvic pain indicates an advanced disease. However, up to 20% of women may be asymptomatic.

Clinical findings

Premalignant lesions of the vagina are divided into low grade (LSIL) and high grade (HSIL). LSIL (VAIN 1) may be associated with either low-risk or high-risk HPV and it represents productive or transient infections that may regress. In contrast, HSIL represents transforming high-risk infections.

A thorough history-taking and physical exam, including a digital exam, a rectovaginal exam, a speculum exam and palpation of inguinal nodes are important aspects of the clinical evaluation of a patient with suspected vaginal cancer. It is vital to visualize the entire vagina by rotating the speculum to expose anterior and posterior surfaces.

Women with HSIL are usually asymptomatic and the majority of women are aged over 60 years. HSIL can be seen in younger women, especially in immunocompromised individuals (HIV and transplant patients). Risk of progression of HSIL to invasive cancer has been found to range between 2% and 12% (5).

Differential diagnoses

1. Herpes simplex
2. Syphilis
3. Vaginal trauma
4. Vaginal atrophy
5. Gartner duct cysts
6. Bartholin gland cysts
7. Vaginal adenosis.

Investigations

1. Packed cell volume and complete blood count (detects the extent of blood loss from vaginal bleeding episodes)
2. Electrolyte, urea and creatinine (detects renal function impairment)
3. Cystoscopy (visualizes tumour spread to bladder mucosa)
4. Proctoscopy (visualizes tumour spread to rectum)
5. Chest x-ray (detects metastasis to lungs)
6. Magnetic resonance imaging (MRI) of the pelvis (to stage the vaginal neoplasms to assess tumor size, local tumor extent, and the presence of lymph node metastases)
7. Colposcopy with acetic acid and/or Lugol iodine is indicated if a woman has an abnormal vaginal cytological smear and no gross abnormality. Biopsies of colposcopically abnormal areas (acetowhite areas with punctation and/or punctation and mosaicism) is essential for the diagnosis. (5)
8. Vaginal biopsy (the gold standard for diagnosing vaginal cancer)

Staging

Ia and 1b: The cancer is only in the vagina and is no/or larger than 2.0 cm

IIa and 11b: The cancer has grown through the vaginal wall, but not as far as the pelvic wall and is no /or larger than 2.0 cm It has not spread to nearby lymph nodes or to distant sites

IIIa and 111b: The cancer can be any size and might be growing into the pelvic wall, and/or growing into the lower one-third of the vagina and/or has blocked the flow of urine (hydronephrosis), which is causing kidney problems. It has also spread/not spread to nearby lymph nodes in the pelvis or groin (inguinal) area but not distant sites

IVa: The cancer is growing into the bladder or rectum or is growing out of the pelvis. It might or might not have spread to lymph nodes in the pelvis or groin (inguinal area). It has not spread to distant sites

IVb: The cancer has spread to distant organs such as the lungs or bones. It can be any size and might or might not have grown into nearby structures or organs. It might or might not have spread to nearby lymph nodes (5)

Treatment

Treatment of precancerous lesions of the vagina must be individualized. Biopsy proven LSIL lesions can be followed up with observation only (repeat smears and colposcopy), especially if women have non-oncogenic strains of HPV. The various modalities of treatment for HSIL lesions include laser ablation, surgical excision, and topical treatments such as imiquimod and topical chemotherapy with 5-fluorouracil (5FU) (5).

Stage I and II vaginal cancers are generally treated with surgery or radiation therapy. Advanced vaginal cancers are treated with radiation therapy and the simultaneous administration of combined chemotherapy(2). There is a limited role for surgery in advanced vaginal cancers because of the proximity of the urethra and rectum.

In vaginal cancers that originate from the upper vagina, radical hysterectomy (if the uterus is present) plus radical vaginectomy and pelvic lymphadenectomy is an option(6). For lower vaginal cancers, radical excision with groin node dissection is a good treatment option. The aim of surgery is a 1 cm disease-free margin(7). Radiation is the cornerstone of treatment for vaginal cancer, especially in the advanced stage of the disease and it combines EBRT and intracavitary radiotherapy (ICRT) or brachytherapy. Its major advantage is organ preservation.

Follow up

The main determinant of prognoses in carcinoma of the vagina is the stage of disease at the time of diagnosis. Other factors include histology, size, and the patient's age. The five-year disease-specific survival rates of 85% for patients with Stage I disease, 78% for patients with Stage II, and 58% for 46 patients with Stages III–IVA. Among the factors associated with better overall survival were younger age, absence of distant metastasis, embryonal histology, negative lymph nodes, and the performance of surgery (5)