Cancer incidence and survival (1997-2006) among adolescents and young adults in the north of Portugal.

ABSTRACT

Cancer is the first cause of natural death among young subjects. Population-based statistics are important to evaluate the burden of disease and the effectiveness of healthcare provision. We aimed to describe cancer incidence and survival among adolescents (15-19 years) and young adults (20-24 years) in the north of Portugal. Data on the cancers diagnosed between 1997 and 2006 were obtained from the Portuguese North Region Cancer Registry, and incidence rates were computed. Vital status was determined until December 2010. Survival was estimated using the Kaplan-Meier survival function. Trends on cancer incidence were assessed using the Joinpoint regression analysis. A total of 1223 cases were diagnosed 441 among adolescents and 782 among young adults. Overall incidence rate was 198.3 per million adolescents [95% confidence interval (95% CI) 135.7-260.9] and 306.2 per million young adults (95% CI 262.3-350.0). The most frequent tumors were Hodgkin lymphoma (adolescents 21.0%; young adults 14.8%), thyroid carcinoma (adolescents 11.5%; young adults 16.2%), and germ cell tumors (adolescents 11.1%; young adults 16.3%). Cancer incidence significantly increased among young adults [annual average percent change 3.6%, (95% CI 1.7-5.4)], while appears to vary randomly among adolescents. Overall five-year observed survival was 77.2% (95% CI 72.9%-80.8%) among adolescents and 81.3% (95% CI 78.4%-83.9%) among young adults, lower in males. In conclusion, cancer incidence among adolescents and young adults is higher in the north of Portugal than in other European countries, especially of thyroid tumors. Between 1997 and 2006, the incidence increased significantly in young adults.