Vulvar cancer

The vulva is a general term for a woman’s external sexual organs (genitals) which are part of the female reproductive system.

The main parts of the vulva are the:

• mons pubis – the soft, fatty mound of tissue covered with pubic hair, above the labia
• labia majora – two large, outer lips, which surround the inner lips known as labia minora
• labia minora – two inner lips (may be smaller or thinner than the labia majora)
• clitoris – the main organ for sexual pleasure in women. It is located where the labia minora join at the top. During arousal, the clitoris fills with blood and becomes erect, and its stimulation can lead to sexual climax (orgasm)
• Bartholin glands – two small glands near the opening of the vagina. They produce mucus to lubricate the vagina.

The vagina

Sometime called the birth canal, the vagina is a muscular channel about 7–10 cm long that extends down from the neck of the uterus (called the cervix) to the vulva. The vagina is the passageway through which menstrual blood flows, sexual intercourse occurs and a baby is born.

Urethra, anus and perineum

Beneath the clitoris is the urethra, for passing urine. Further back is the entrance to the vagina, and below that is the anus. The area of skin between the vagina and the anus is called the perineum.

Each year, about 300 Australian women are diagnosed with vulvar cancer. It most commonly affects women who have gone through menopause, and the average age at diagnosis is 67. However, vulvar cancer can occur in younger women.

Squamous cell carcinoma (SCC)

• starts in thin, flat (squamous) cells that line the vulva
• makes up about 90% of vulvar cancers
• includes verrucous carcinoma, a rare type of vulvar cancer that looks like a large wart and grows slowly

Vulvar melanoma

• a type of skin cancer that develops from the cells that give the skin its colour (melanocytes)
• makes up about 2–4% of vulvar cancers

Adenocarcinoma

• develops from the mucus-producing (glandular) cells in the Bartholin glands or other vulvar glands
• includes extramammary Paget’s disease, which looks like eczema
• a rare type of vulvar cancer

Sarcoma

• starts in muscle, fat and other tissue under the skin
• tends to grow faste than other vulvar cancers
• a rare type of vulvar cancer

Basal cell carcinoma (BCC)

• starts in tall cells in the lower layer of the skin
• the most common form of skin cancer, but a very rare type of vulvar cancer

The exact cause of vulvar cancer is uknown, but some factors increase the risk of developing it:

• Vulvar intraepithelial neoplasia (VIN) – This is a precancerous condition that causes changes in the skin of the vulva. The vulva may itch, burn or feel sore. VIN may disappear on its own, but most women with VIN need some treatment. The condition sometimes becomes cancerous – about one in three women with vulvar cancer also has VIN.
• Human papillomavirus (HPV) – Also known as the wart virus, HPV is a sexually transmitted infection that can cause women to develop VIN. It can be many years between the initial infection with HPV and the first signs of VIN or vulvar cancer. HPV is a very common virus and most women with HPV don’t develop vulvar or any other type of cancer.

  HPV has been linked to a number of cancers, including vulvar, vaginal, cervical, anal and oral cancers. Studies have shown that HPV vaccination can reduce the risk of having abnormal cell changes that may lead to cancer, even in older women. Talk to your doctor about whether the HPV vaccination may be of benefit to you.

• Abnormal Pap test – If a woman has had any abnormal cell changes detected on a Pap test, she has a slightly higher risk of developing vulvar cancer.
• Other skin conditions – Some skin conditions such as vulvar lichen planus and vulvar lichen sclerosus can cause itching and soreness. If not treated, these conditions can cause permanent scarring. In a small number of women, they may develop into cancer after many years.
• Other cancers – Women who have had cervical cancer or vaginal cancer have an increased risk of developing vulvar cancer.
• Smoking – Cigarette smoking increases the risk of developing VIN and vulvar cancer. This may be because smoking can make the immune system work less effectively.
• Weakened immune system – Women who have had an organ transplant or who have human immunodeficiency virus (HIV) may be at a higher risk of developing vulvar cancer because their immune system is not working normally.

  Although HPV is sexually transmitted, vulvar cancer itself is not contagious and it can’t be passed on to other people through sexual contact. It is also not caused by an inherited faulty gene, so it can’t be passed on to children.