An epidemic of vulvar cancer in young women: investigating the role of Human Papillomavirus and genetic susceptibility

外阴癌是一种罕见的疾病；1993-1997年，澳大利亚经年龄调整后的发病率为每100,000名妇女中有1.4例(平均每年207例)，与大多数其他国家的发病率相似。在居住在北领地偏远社区的年轻土著妇女中发现了外阴癌病例的流行。在这些社区，外阴癌在年龄在50岁以下的女性中的发病率是澳大利亚总人口的50多倍。这些社区的女性也经历了比NT其他地方更高的高级别外阴上皮内瘤变(外阴癌的前驱症状)的发生率。外阴癌通常在老年女性中比年轻女性更常见。在年轻女性中，外阴癌和VIN被认为是由感染致癌株人类乳头瘤病毒(HPV)引起的，特别是被称为HPV16的株。在老年女性中，外阴癌不是由HPV引起的。在新界的偏远社区，外阴癌几乎全部发生在年轻女性中，这些社区的老年女性患癌症的数量与澳大利亚总人口的预期数量相似。这个项目将调查这次外阴癌和高级别VIN流行的原因。它将调查HPV16是否在这些社区比澳大利亚其他地方更普遍；这些社区中是否有HPV16变异株更容易致癌，以及这种疾病是否更常发生在家庭中，这意味着这些社区的女性遗传外阴癌和VIN的易感性增加。该项目将有助于增加我们对外阴癌和VIN的了解，有助于控制这一流行病，并告知新的HPV疫苗是否可能在这些社区有效地预防外阴癌。

Vulvar cancer is a rare disease; in 1993-1997 the age-adjusted incidence rate in Australia was 1.4 per 100,000 women (average 207 cases per year), similar to the incidence in most other countries. An epidemic of cases of vulvar cancer has been identified in younger Indigenous women living in remote communities in the Northern Territory (NT). Vulvar cancer is over fifty times more common in women aged less than 50 years in these communities than in the total Australian population. Women in these communities also experience higher rates of high-grade Vulvar Intraepithelial Neoplasia (a pre-cursor to vulvar cancer), than elsewhere in the NT. Vulvar cancer is usually much more common in older women than younger women. In young women vulvar cancer and VIN are thought to be caused by infection with cancer causing strains of human papillomavirus (HPV), particularly the strain known as HPV16. In older women, vulvar cancer is not caused by HPV. In the remote communities in the NT, vulvar cancer is occurring almost entirely in young women, the amount of cancer occurring in older women in these communities is similar to the amount expected in the total Australian population. This project will investigate the cause of this epidemic of vulvar cancer and high-grade VIN. It will investigate whether HPV16 is more prevalent in these communities than elsewhere in Australia; whether there is a variant strain of HPV16 in these communites that is more virulent at causing cancer, and whether the disease occurs more commonly in families, which would mean that women in these communities inherit an increased susceptibility to vulvar cancer and VIN. This project will help to increase our understanding of vulvar cancer and VIN, help to control this epidemic, and inform whether the new HPV vaccines may be effective in preventing vulvar cancer in these communities.