Trends in incidence, mortality, and survival of cutaneous malignant melanoma over three decades: a population-based study in Southern Spain.

Background: Cutaneous malignant melanoma (CMM) represents a global public health problem. Epidemiological studies about CMM trends tend to focus on single indicators or lack information about tumor characteristics that can help gain a more thorough understanding of CMM epidemiology.

Objectives: To fill this gap, we studied CMM trends in incidence, mortality, and survival over three decades and considering sex, age, and tumor characteristics.

Methods: Data were obtained for all new cases of CMM diagnosed 1985-2017 from the population-based cancer registry in Granada (Southern Spain) and for deaths due to CMM by the Ministry of Health of the Spanish government. Incidence, mortality, and survival estimates were obtained according to sex, age group, anatomical site, histological type, Breslow index, and Clark level. Observed and net survival were calculated for 1, 3, and 5 years using the Kaplan-Meier and Pohar-Perme methods, respectively. Log-linear jointpoint regression was used to assess temporal trends in age-standardized rates of incidence and mortality.

Results: Between 1985-2017, 2,446 patients aged 15 years and older were newly diagnosed with CMM. There was a significant increase in incidence, both in men and women (APC 4.4% and 3.7% respectively), mainly in superficial spreading and nodular melanomas, and more pronounced among those with <1mm Breslow index. Mortality rates increased, mainly driven by increases among men and individuals ≥65 years old. Nodular melanoma had the worst prognosis, with a 5-year observed survival of 67.1% compared to survival greater than 90% for the other subtypes. 5-year net survival improved from 78.3% in 1985-1997 to 88.6% in 2008-2017, with a clear trend by Breslow index.

Conclusions: The incidence of melanoma in early stages in Southern Spain has increased over the past decades. This has been accompanied by noticeable improvements in mortality and survival, especially among younger age groups, suggesting the potential effectiveness of prevention strategies, and new treatment regimens.