Vulvar cancer incidence and net survival in Sweden 1960 to 2019: A population-based national study

IntroductionVulvar cancer is a rare gynecological cancer affecting mostly older women. The aim of this population-based study was to investigate the incidence and net survival of vulvar cancer in Swedish women from 1960 to 2019.Material and methodsData were retrieved from the mandatory Swedish Cancer Registry consisting of all women diagnosed with vulvar cancer between 1960 and 2019. Only women with a morphologically verified diagnosis of vulvar cancer were included. The individuals were then further matched with the Swedish Death Registry up until May 31, 2020.ResultsIn total, 8499 women were included with the following morphologies: squamous cell carcinoma 7250 (85.8%), malignant melanoma 539 (6.4%), adenocarcinoma 401 (4.8%) and other: 259 (3.1%). More than 50% of vulvar cancer cases occurred in women aged between 65 and 84 years of age. The 5-year age-standardized net survival increased from 53.0% (95% confidence interval [CI] 48.9-57.5) in 1960 to 72.1% (95% CI 68.8-75.5) in 2019. The proportion of adenocarcinoma among all cases increased from 2.0% to 8.7% between the 1960s and 2010s and an increase in age-standardized 5-year net survival was found for adenocarcinoma.ConclusionsThe age-standardized incidence of vulvar cancer cases in Sweden was stable between 1960 and 2019. During the study period, an increase in adenocarcinoma and a decrease in malignant melanoma cases was found. Five-year net survival increased by 20 percent units during the study period. For squamous cell carcinoma, an increased age-specific 5-year net survival was observed for all age groups, apart for women aged >= 85. This Swedish population-based study describes the incidence and net survival of vulvar cancer (1960-2019). The age-standardized incidence of vulvar cancer cases in Sweden in this period was stable: age-standardized incidence 1.88/100 000 women (1960) and 1.75/100 000 women (2019). During the study period, an increase in adenocarcinoma cases and a decrease in malignant melanoma cases was found. The 5-year net survival increased by 20 percent units during the study period. For squamous cell carcinomas of the vulva, an increased age-specific 5-year net survival was observed for all age groups apart for women aged >= 85.image