Anatomy of the vulva
The vulva is a general term referring to the external female genital organs and includes the mons, labia majora and labia minora, the clitoris, the urethral meatus and the opening of the vagina. The mons veneris is the rounded fatty prominence in front of the pubic bone. The labia majora are two prominent skin folds extending down from the mons to the perineum. The labia minora are two small skin folds located inside the labia majora. The clitoris is an erectile sensitive structure analogous to the penis in the male, located where the labia minora meet at the top. The opening of the urethra is located about an inch below the clitoris near the opening of the vagina.
Cancer of the vulva can take many years to develop. Before it does, early changes occur in the cells of the vulva. The name given to these abnormal cells, which are not cancerous but may lead to cancer, is vulva intra-epithelial neoplasia (VIN). Some doctors call these changes precancerous, meaning that the cells have the potential to develop into cancer if left untreated. It is important to know that most women with VIN do not develop cancer. VIN may also be referred to as dysplasia, and Bowen’s disease. This condition is diagnosed by tissue biopsy and is characterized by a full thickness disorder of maturation of the squamous epithelium. It is easy to see on examination and may appear as a raised red, white or pigmented patch. A simple biopsy will confirm the diagnosis.
It is best treated by excision or sometimes by laser vaporisation. If a large area is involved and must be removed, then a skin graft can be applied. These premalignant conditions are likely to recur after treatment so continued follow up is a necessity. Another condition that can occur on the vulva and also cause itching and soreness is called lichen sclerosis. It is not a premalignant change, but an atrophy or thinning of the skin. It will not be improved by anti-yeast medications either. It can also be diagnosed by biopsy.
Most women with vulva cancer present to the local doctor with a history of itching and burning. The itch may be present for some time, before the appearance of a lump or bump in the region. Commonly the condition is misdiagnosed as a yeast infection and patients often prescribed a number of creams that are ineffective. Most patients are older; vulva cancer is by no means restricted to this age group. A significant percentage of women will be younger and may have an associated medical condition that causes immune suppression like diabetes.
There is usually an obvious growth on the skin or an ulcerated area. Diagnosis is by simple biopsy. These cancers are usually slow growing and do not spread early. When they do spread it is usually by way of the lymph nodes. The regional lymph nodes are located at the top of the thigh in the groin area.
The most common type of cancer is a skin cancer known as squamous cell carcinoma. There are many other types of cancers of the vulva that are less common and include adeno or gland cancers and melanoma. The type of melanoma that occurs on the vulva is not sun related.
The stage of a cancer is a term used to describe its distribution and whether it has spread beyond the vulva region. Knowing the extent of the cancer helps the doctors to decide on the most appropriate treatment. Vulva cancer is divided into four stages. Early cancer that is confined to the vulva and is smaller than 2cm is stage I, whereas if it is larger than 2cm but still confined to the vulva region, is stage II. The stages of vulva cancer are described below:
Stage 1 – Tumor confined to the vulva
1A Lesions ≤2 cm in size, confined to the vulva or perineum and with stromal invasion ≤1.0 mm*
1B Lesions >2 cm in size OR any size with stromal invasion >1.0 mm, confined to the vulva or perineum*
Stage 2 – Tumor of any size with extension to adjacent perineal structures (lower/distal 1/3 urethra, lower/distal 1/3 vagina, anal involvement)
Stage 3 – Tumor of any size with or without extension to adjacent perineal structures (lower/distal 1/3 urethra, lower/distal 1/3 vagina, anal involvement) with positive inguino-femoral lymph nodes
3Ai One lymph node metastasis, ≥5 mm
3Aii One to two lymph node metastases, <5 mm
3Bi One to two lymph node metastases, <5 mm
3Bii Three or more lymph node metastases, <5 mm
3C Lymph node metastasis with extracapsular spread
Stage 4 – Tumour invades other regional (2/3 upper urethra, 2/3 upper vagina), or distant structures
4A Tumour invades any of the following: Upper urethral and/or vaginal mucosa, bladder mucosa, rectal mucosa or fixed to pelvic bone, or fixed or ulcerated inguino-femoral lymph nodes
4B Any distant metastasis including pelvic lymph nodes
*The depth of invasion is defined as the measurement of the tumour from the epithelial-stromal junction of the adjacent most superficial dermal papilla to the deepest point of invasion
Grading refers to the appearance of the cancer cells under the microscope. There are three grades: grade 1 (low grade), grade 2 (moderate grade) and grade 3 (high grade). Low grade means that the cancer cells look very like the normal cells of the vulva. They are usually slowly growing and less likely to spread. In high grade tumours the cells look very abnormal or “angry looking” and are likely to grow more quickly and spread.
Treatment is highly individualized with a trend toward conservative type surgery. In deciding what surgery is undertaken, your surgeon will consider a number of variables including: (i) how big the cancer is and where it is located on the vulva (ii) how deep the cancer is growing through the skin (iii) whether there is evidence from the biopsy that cancer is starting to break away and is appearing in lymphatic vessels (iv) the grade of the cancer which is similar to how angry the cells are appearing under the microscope (v) whether the lymph nodes or glands in the groins are enlarged (vi) the wishes of the patient(vii) the condition of the skin near the cancer (viii) whether there are any other gynaecological problems present like prolapse (ix) if there is evidence of cancer or precancer elsewhere in the lower genital tract.
Wide removal of the cancer, known as radical local excision (RLE) or radical vulvectomy is the standard treatment of all operable cancers. The cancer needs to be removed with at least a 1cm margin to make sure all the cancer is removed.
Removal or some or all of the lymph glands in the groin is an important component of surgery to make sure the cancer has not spread. We occasionally use a new technique known as sentinel node biopsy where a radioactive injection is made in the cancer and pictures are taken to attempt to localize the first node where cancer might spread. This potential first node of spread is known as the “sentinel node”.
Wound infections are quite common after surgery. Other complications that may be experienced include numbness in the region of the surgery and on front of your thigh. This is caused by bruising and damage to the very fine nerves that supply these regions. Often this numbness or pin and needles are permanent. Some women will complain of leg swelling, known as lymphoedema and this can vary in severity from very mild to very bad and can be somewhat difficult to manage.
Radiation therapy is sometimes used when the cancer is very large to shrink it down so that it can be removed later with less radical surgery. Preoperative radiation therapy is often combined with chemotherapy to increase its effectiveness.
If the cancer has been completely removed with wide margins and there is no spread to the lymph glands, then most patients will not need any further treatment. If there is some concern by your surgeon that the cancer is likely to come back, then radiation therapy may be recommended to reduce this risk.
The main reason why radiotherapy is given after surgery is if the cancer has spread to one or more lymph glands.
C). Definitive Radiation Therapy
In young patients with small cancers especially if they are near or on the clitoris, surgery may not be performed, favoring primary irradiation therapy instead.
Chemotherapy is commonly added to radiation therapy to help in the effectiveness of the therapy. It is rarely used by itself except where patients have advanced cancer and surgery or radiation therapy cannot be used. In such a setting the aim of the treatment is palliation or control of symptoms, not really for cure.
After treatment is completed, patients are followed up closely and regularly to make sure the cancer does not return. This involves 3 monthly visits to start with. Your doctor will ask you some questions, perform an examination including a pelvic examination. He will look at and examine very closely the vulva region, particularly where the cancer was and feel the groin region to make sure the lymph nodes are not enlarged. A pap test of the cervix will be done regularly to make sure you don’t develop precancer changes of the cervix.