Stage-specific incidence trends of melanoma in an English region, 1996-2015: longitudinal analyses of population-based data.

Abstract

Objective: To examine temporal trends in overall and stage-specific incidence of melanoma. Methods: Using population-based data on patients diagnosed with melanoma in East Anglia, England, 1996-2015, we estimated age-standardised time-trends in annual incidence rates for each stage at diagnosis. Negative binomial regression was used to model trends over time adjusted for sex, age group, and deprivation; and to subsequently examine variation in stage-specific trends by sex and age group. Results: The age-standardised incidence increased from 14 to 29 cases/100,000 persons (i.e. 4% annually). Increasing incidence was apparent across stages but was steepest for stage I (adjusted annual increase: 5% [95% CI: 5%-6%] and more gradual for stage II-IV disease [stage II: 3% [95% CI 2%-4%]; stage III/IV: 2% [95% CI: 1%-3%]). Stage II-IV increase was apparent in men across age groups and in women aged 50+. Increases in incidence were steeper in 70+ year olds, and in men. Conclusion: The findings suggest both a degree of overdiagnosis and a genuine increase in the incidence of consequential illness may be responsible for the observed increasing incidence trends in melanoma in our population during the study period. They also suggest potentially lower effectiveness of public health awareness campaigns in men and older people.