Vulvar carcinoma in Norway: A 50-year perspective on trends in incidence, treatment and survival.

ABSTRACT

OBJECTIVE: To explore trends in vulvar squamous cell carcinoma (SCC) incidence, age and stage at diagnosis, treatment and survival in Norway from 1961 to 2010. METHODS: From 1961 to 2010, 2233 cases of vulvar SCC were extracted from the Cancer Registry of Norway. Data on age at diagnosis, tumor morphology, stage of the disease and treatment were analyzed. Age-standardized incidence rates, adjusted to the Norwegian standard population, were computed. Relative survival was calculated as a ratio of the observed survival in the study population over the expected survival in the background population. Multivariate Cox model was fitted to estimate hazard ratios. RESULTS: The overall incidence of vulvar SCC increased >2.5 fold (from 1.70 to 4.66 per 100,000 women/year; P<0.01). Age-specific incidence rates increased among women aged ≤60years (by 150% in age group 0-39years, 175% in age group 40-49years and 68% in age group 50-59years). From 1971 to 2010, the percentage of patients receiving surgery as only treatment decreased from 81% to 61%, whereas the use of radiation and combination therapy (surgery and radiation) increased from 3% to 11% and 6% to 20%, respectively. 5-year relative survival increased significantly among women ≤80years (from 72% to 83% among women aged ≤60years and from 60% to 65% among women aged 61-80years). CONCLUSIONS: The incidence of vulvar SCC has increased since the sixties, particularly among women younger than 60years. Despite less aggressive surgical treatment, survival has improved.