Changing Trends in Vulvar Cancer Incidence and Mortality Rates in Australia Since 1982

Background The objective of this study was to assess trends in vulvar cancer incidence and mortality in Australia. Methods Case numbers for invasive carcinoma of the vulva (1982-2009) and vulvar cancer deaths (1982-2011) were obtained from the National Cancer Statistics database. Standardized rate ratios (SRRs) were used to assess changes in age-standardized incidence and mortality rates, for all ages and for younger than 60 years and 60+ years. Results Age-standardized incidence rates in women across all ages did not significantly change from 1982-1984 to 2007-2009 (from 2.1 to 2.5 per 100,000 women; SRR from the later to the earlier period, 1.13 [95% CI, 1.00-1.27]). However, there was a significant 84% increase in incidence in women younger than 60 years (SRR, 1.84 [95% CI, 1.49-2.26]), with no change for women 60+ years (SRR, 0.90 [95% CI, 0.79-1.04]). Age-standardized mortality in women across all ages significantly decreased by 22% from 1982-1986 to 2007-2011 (from 0.7 to 0.5 per 100,000 women; SRR, 0.78 [95% CI, 0.66-0.93]). However, this was driven by declines in older women, with stable rates in women younger than 60 years (SRR, 1.05 [95% CI, 0.62-1.79]); rates in 60+ years decreased by 24% (SRR, 0.76 [95% CI, 0.63-0.91]). Conclusion Since the early 1980s, vulvar cancer incidence has increased by more than 80% in women younger than 60 years in Australia, but there has been no increased incidence in older women. These findings are consistent with the possibility of increased exposure to the human papillomavirus in cohorts born after 1950. By contrast, age-standardized vulvar cancer mortality rates have been stable in younger women, but have declined in older women.