A cluster of vulvar cancer and vulvar intraepithelial neoplasia in young Australian Indigenous women

Objective: To describe the epidemiological features of a possible disease cluster of vulvar cancer and pre-cancers in Australian Indigenous women living in the Northern Territory (NT) of Australia. Methods: We identified NT-resident women with a confirmed histological diagnosis of vulvar cancer or high-grade vulvar intraepithelial neoplasia (VIN) between 1 January 1996 and 31 December 2005. Results: Seventy-one women were identified; 32 diagnosed with vulvar cancer and 39 with high-grade VIN. Most women diagnosed were Indigenous, aged less than 50 years and living in remote communities in the East Arnhem (EA) district, on the north-east coast of the NT. The age-adjusted incidence rate of vulvar cancer in EA Indigenous women aged 0-49 years was 31.1 per 100,000 (95% CI 13.1-49.1), over 50 times higher than the national Australian rate (0.4 per 100,000, 95% CI 0.4-0.5) for the same age-group. In the age-group of 0-49 years, the age-adjusted incidence rate of VIN for EA Indigenous women was 34.7 per 100,000 (95% CI 15.2-54.3), compared with 6.7 per 100,000 (95% CI 2.0-11.4) for Indigenous women living elsewhere in the Top End of the NT. Conclusion: These data provide evidence of a geographic cluster of vulvar cancer in remote Indigenous communities in northern Australia.