Trends of incidence and survival in squamous-cell carcinoma of the anal canal in France: a population-based study.
Résumé
Data on anal cancer epidemiology are rare. The aim of this study was to report on trends of incidence and survival for anal cancer in France before the implementation of the human papilloma virus vaccine. This analysis was carried out on 1150 squamous-cell carcinomas of the anal canal diagnosed from 1989 to 2004 in a population of 5.7 million people covered by eight population-based cancer registries. Time trends in incidence were modeled using an age-period-cohort model. Net survival rates were obtained using the recently validated unbiased Pohar-Perme estimator. The incidence of squamous-cell carcinoma of the anal canal increased from 0.2 to 0.5/100 000 person-years among men and from 0.7 to 1.3/100 000 person-years among women from 1982 to 2012. Among women, the increase peaked after 2005, with an annual percentage change of +3.4% between 2005 and 2012, as compared with +2.6% among men. The net survival was 56% (95% confidence interval, 49-64) at 5 years and 48% (33-70) at 10 years among men. It was higher among women, at 65% (61-69) and 56% (50-63) at 5 and 10 years, respectively. The prognosis improved between 1989-1997 and 1998-2004. This improvement was slightly greater for men than for women, thus progressively reducing the gap between sexes. The incidence of squamous-cell anal canal cancer increased slightly among both sexes, but the increase was more marked among women than among men. The potential benefit of prophylactic female human papilloma virus vaccination against cervical cancer in France should be further evaluated.