Brief Report: Increase in Melanoma Incidence in Ontario.

BACKGROUND: Melanoma is a serious, potentially lethal disease. It is one of very few common cancers whose incidence is rising in North America.

OBJECTIVES: The objective of this study was to examine trends in melanoma incidence in Ontario, Canada's most populous province, over the past 20 years.

METHODS: Using data from the Ontario Cancer Registry (OCR), this retrospective cohort examined all incident cases of melanoma in Ontario from 1990 to 2012. Generalized linear modeling was used to evaluate changes in melanoma incidence over time, adjusting for age and sex using direct standardization with the 1991 Canadian census population. Tests for trend for changes in the distribution of cases by age, sex, socioeconomic status, and rurality status were also calculated.

RESULTS: Our results show a statistically significant increasing incidence of melanoma in Ontario from 9.3 cases per 100 000 in 1990 to 18.0 cases per 100 000 in 2012 ( P for trend <.001, adjusted for age and sex). Incidence rates show stabilization from 2010 to 2012.

CONCLUSION: Our study reveals a marked increase in melanoma incidence in Ontario, more than doubling over the past 20 years but with a stabilization more recently. Adequate availability of dermatology services may be important to ensure satisfactory care for the increased caseload and to ensure that cases may detected at an early stage with a good prognosis.