The contribution of nodular subtype to melanoma mortality in the United States, 1978 to 2007

Abstract

Objective: To gain insight into reducing melanoma mortality by examining epidemiologic trends by subtype with emphasis on the contribution of each subtype to melanoma-related death.

Design: Retrospective population-based cohort study.

Setting: Original 9 registries of the Surveillance, Epidemiology, and End Results Program from 1978 to 2007.

Participants: A total of 111,478 patients with histologically confirmed invasive melanoma.

Main outcome measure: Proportion of ultimately fatal melanomas by subtype.

Results: Among melanomas of known subtype, superficial spreading melanoma comprised 66% of incident melanomas and 46% of ultimately fatal melanomas; nodular melanoma comprised 14% of incident melanomas and 37% of ultimately fatal melanomas. For superficial spreading melanoma, overall incidence per 100,000 per year increased (from 4.28 to 6.63), ultimately fatal incidence remained stable (at 0.56 to 0.51), and 10-year relative survival increased (from 90.6% to 96.5%) when comparing successive 5-year intervals. In contrast, for nodular melanoma, the overall incidence (1.30-1.32), ultimately fatal incidence (0.46-0.44), and 10-year relative survival rate (61.8%-61.5%) remained stable. Epidemiologic trends of melanoma, not otherwise specified, were similar to superficial spreading melanoma. There was a strong negative correlation between the proportion of melanoma, not otherwise specified, among all melanomas, and the proportion of superficial spreading melanoma, among melanomas of known subtype (r = -0.80; P = .01), across the registries.

Conclusions: Superficial spreading and nodular melanoma constitute similar proportions of ultimately fatal melanomas. Although incidence of and survival from superficial spreading melanoma have increased from 1978 to 2007, neither the incidence of nor survival from nodular melanoma has changed. Public health efforts should include a focus on nodular melanoma for maximum reduction of melanoma mortality.