Introduction

Vulval cancer is rare and constitutes approximately 3% of gynaecological cancers worldwide. It is estimated that approximately 27 000 women are diagnosed with vulval cancer each year and the rates range from less than 0.3 per 100 000 women in parts of Asia to more than 1.5 per 100 000 in North America and Europe. This variation is thought to be due to differing prevalence of human papillomavirus (HPV) infection and other factors such as smoking.

In the UK, vulval cancer accounts for fewer than 1% of all cancers (excluding non-melanoma skin cancer) and 6% of gynaecological cancers. In 2007, there were 1120 new cases diagnosed, giving an incidence of 2.4 (European standardised rate per 100 000 population). In 2008, the mortality rate was 0.7 per 100 000 population, with 400 deaths. It has been estimated that the lifetime risk of developing vulval cancer is one in 316 women in the UK.

The incidence of vulval cancer has increased since the mid-1990s owing to the increased incidence in younger women, which has doubled over the past 30 years. The proportion of cases diagnosed in women under the age of 50 years increased from 6% in 1975 to 13% in 2005. A similar trend has been seen in other countries and has been linked to the increase in HPV-induced vulval intraepithelial neoplasia (VIN).

The disease has two aetiologies. The first, associated with high-risk HPV infection, usually occurs in young women and is related to VIN and to basaloid carcinoma.