What is vulval cancer?
Vulval (or vulvar) cancer or cancer of the vulva accounts for about 3–5% of female genital cancers. It can occur on any part of the vulva but most often affects the clitoris, the inner edges of the labia majora, and the labia minora.
Over 90% of vulval cancers are squamous cell carcinomas (SCC). The next most common type of vulval cancer is melanoma but this accounts for less than 5% of all vulval cancers. Other rare vulval cancers are basal cell carcinoma (BCC), Bartholin's gland cancer and extramammary Paget disease.
Who gets vulval cancer and why?
Vulval cancer may affect women of all ages but 70% of women are aged > 60 years. Human papillomavirus (HPV) is responsible for about 60% of squamous cell carcinomas of the vulva.
Some squamous cell vulval cancers may be preceded by precancerous changes that may last for several years. This precancerous condition of the vulva is known as vulval intraepithelial neoplasia (VIN), and when associated with human papillomavirus infection, it is also known as high-grade squamous intraepithelial lesion (HSIL). Vulval cancer is more common and more aggressive in cigarette smokers.
Vulval lichen sclerosus and chronic erosive lichen planus predispose to differentiated VIN (dVIN), which can also give rise to vulval squamous cell carcinoma. Vulval cancer associated with dVIN is unrelated to HPV infection.
What are the signs and symptoms?
Signs and symptoms of vulval cancer depend on the type of cancer involved.
Squamous cell carcinoma
- Red, pink or white nodule or nodules or plaques
- May have a wart-like and/or raw surface if ulcerated
- Affected area of vulva may appear white and feel rough
- About 50% of women complain of itching or pain
- Other symptoms include painful urination, burning, bleeding and discharge not associated with a normal menstrual period
Extramammary Paget disease
- Moist red asymmetrical oozing plaque
- May cause burning and itching
Basal cell carcinoma
- Painless red patch, nodule or ulcer
- Appearance of a new pigmented lesion or change in a pre-existing mole
Bartholin gland cancer
- Persistent cystic or thickened tender mass on either side of the opening to the vagina
Diagnosis and staging of vulval cancer
Skin biopsy of the lesion is performed to get an accurate diagnosis of vulval cancer. Under microscopy, the presence of malignant cells along with other histological findings will confirm the diagnosis and the type of vulval cancer.
After initial diagnosis of vulval cancer, a specialist doctor will perform a thorough examination to determine the stage of the cancer. This depends on:
- The size of the tumour
- How deeply the tumour has invaded tissues at the site of origin
- The extent of any invasion into surrounding organs or lymph nodes.
Determining the cancer's stage is an important factor as it directs what treatment plan should be used. The FIGO (International Federation of Gynaecology and Obstetrics) System of Staging is commonly used to describe vulval cancer staging. The system classifies the disease from Stage 0 through to Stage IV. Stage 0 represents precancerous lesions whilst Stage IV the most advanced stages of cancer (invasion and metastases of surrounding and distant tissues and lymph nodes).
Most patients will have blood tests, a chest X-ray and CT scan of the abdomen and pelvis to help stage the cancer.
In a large centre in which there is an experienced multidisciplinary team, some patients with vulval carcinoma may be offered sentinel node biopsy to determine if there microscopic metastases. Requirements are:
- Unifocal tumour
- Small tumour, < 4 cm in diameter
- No palpable lymph nodes.
What is the treatment of vulval cancer?
Treatment of vulval cancer depends on the type of cancer and the stage of the cancer. In general, diagnosis and treatment during the early stages of cancer have a much better outcome. There are basically 3 types of treatment options available.
- Surgery (cutting out the cancer)
- Radiation therapy (high-dose x-rays or other high-energy rays to kill cancer cells)
- Chemotherapy (drugs to kill cancer cells, eg, cisplatin, gemcitabine)
Surgery is the most common form of treatment for vulval cancer. Several methods may be used and are often dictated by the stage of the cancer One of these is wide local excision, which takes out the cancer and some of the normal tissue around the cancer. Another is radical local excision which takes out the cancer and about a 1cm portion of surrounding tissue.
The lymph nodes in the groin are usually removed when the cancer is 1 mm or greater in depth, but in some centres sentinel node biopsy is performed if the nodes are not clinically involved.
Complications of surgery often relate to destruction of the lymphatic channels in the groin and include lymphocysts and lymphoedema in up to 70% of patients undergoing lymph node removal.
Radiation therapy and chemotherapy are most often used in patients with locally advanced or recurrent vulval cancer.
How can vulval cancer be prevented?
HPV vaccination is expected to reduce the incidence of HPV-associated vulval cancer in the future. Quadrivalent HPV vaccination (Gardisil™) protects against HPV 16, 18, 6 and 11; 9-valent Gardisil™ also protects against HPV 31, 33, 45, 52, and 58. In New Zealand, funded vaccination has been offered to adolescent girls since 2006.
Most sexually active men and women will acquire at least one subtype of genital HPV, the majority within the first 5 years of onset of sexual activity. For maximum efficacy, vaccination needs to be undertaken before the onset of sexual activity. HPV infection rates can be reduced by use of condoms during intercourse and limiting the number of sexual partners.
Apart from its role in causing anogenital warts, vulval high-grade squamous epithelial lesion and vulval cancer, HPV infection can also lead to cervical intraepithelial neoplasia (CIN), anal intraepithelial neoplasia (AIN), vaginal intraepeithelial neoplasia (VAIN) or another invasive tumour of the anogenital tract such as anal cancer.
It is important for all women to have regular cervical smears according to the national screening programme. These offer an opportunity for regular vulval examinations to detect vulval cancer early.