Incidence of cutaneous malignant melanoma in the Ottawa region: 1996 to 2006

Background: The incidence rates of invasive primary cutaneous malignant melanoma in Canada have shown a gradual tapering in recent years, after decades of increases. This trend suggests that the incidence of melanoma in Canada is stabilizing; however, knowledge of the recent trend for both in situ and invasive tumors was lacking. Objective: The purpose of this study was to examine the temporal trend of both in situ and invasive melanoma within the Ottawa region over a 10-year period. Methods: The histopathology of cutaneous melanomas diagnosed in the Ottawa region was obtained for the years 1996, 2001, and 2006 from the main diagnostic centers servicing the area; however, not all melanomas have been accounted for. All rates are expressed per 100,000 population per year. Results: Melanoma incidence decreased between 1996 and 2001 (-3.83) and increased between 2001 and 2006 (+7.46; p ≤ .05). This increase is mainly attributable to in situ melanoma (+5.49; p ≤ .05). There has been no statistically significant change in invasive melanoma. Conclusions: Invasive melanoma incidence in the Ottawa region remained stable, whereas in situ melanoma incidence increased.