Incidence trends and clinical–pathological characteristics of invasive cutaneous melanoma from 1980 to 2010 in the Canton of Zurich, Switzerland

The aims of this paper are to describe the incidence trends of invasive cutaneous melanoma in the Canton of Zurich and to evaluate clinical and pathological factors such as cancer subtype, localization, age and Breslow thickness. A retrospective analysis was carried out with data from the population-based Cancer Registry of Zurich and Zug located in Zurich. A total of 8469 cases in 8034 different patients of invasive cutaneous melanoma were registered for the period 1980-2010 in the Canton of Zurich. Incidence trends were age standardized to the European standard population. Joinpoint regression was used to compute changes in incidence and mortality rates, measured as the annual percent change (APC). The most common subtypes of cutaneous melanoma were superficial spreading melanoma (SSM, 41.1%), followed by nodular melanoma (16.5%), lentigo maligna melanoma (13.5%), acral-lentiginous melanoma (5.0%) and other types of melanoma (2.8%); 21.1% were melanoma not otherwise specified. The trunk was the most frequent location (30.8%), followed by the lower limb and hip (26.4%) and the upper limb and shoulder (22.8%). Statistically significantly increasing incidence trends were observed for both men (APC=3.0%) and women (APC=2.1%). Incidences of SSM and melanoma not otherwise specified were the histological subtypes for which a significant increase in incidence was observed (APC for the period 1980-2010=3.2% for both). In terms of Breslow thickness, thin melanomas (0.01-1.00 mm) showed an increasing incidence. The incidence of melanoma increased in both men and women between 1980 and 2010. In terms of the different subtypes and Breslow thickness, increasing incidences of the SSM and of thin melanomas (0.01-1.00 mm) were observed. These observations are in agreement with other studies from Southern and Western Switzerland as well as other European countries and the USA.