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

Abstract

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 tumour 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 that considered sex, age and tumour characteristics.

Methods: Data were obtained for all patients with a new diagnosis of CMM during 1985-2017 from the population-based cancer registry in Granada (Southern Spain) and for deaths owing to CMM from 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 and 2017, 2446 patients aged ≥ 15 years were newly diagnosed with CMM. There was a significant increase in incidence, both in males and females (annual percentage of change 4.4% and 3.7%, respectively), mainly in superficial spreading and nodular melanomas, and more pronounced among those with < 1 mm Breslow index. Mortality rates increased, mainly driven by increases among males and individuals ≥ 65 years old. Nodular melanoma had the worst prognosis, with a 5-year net survival of 62.7% in the period 2008-2017 compared with survival > 90% for other subtypes. Overall 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 recent 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.