Long-Term Temporal Trends in Survival Among Danish Patients with Advanced Cutaneous Melanoma: A Nationwide Follow-Up Study

INTRODUCTION: Population-based data on survival trends over time among patients with advanced cutaneous melanoma are lacking. We examined changes in mortality for patients diagnosed from 1980 to 2011 in a nationwide historical follow-up study using population-based medical registries from Denmark. MATERIAL AND METHODS: The study population included all Danish patients with an incident diagnosis of advanced (metastatic or unresectable stage IIIA, IIIB, IIIC, or IV) cutaneous melanoma (ie, initial diagnosis for melanoma at stage III/IV) between 1980–2011 and who were followed-up until 2013. For each patient, we randomly matched 100 individuals from the general population on sex and year of birth. Age-standardized mortality rates were calculated by calendar year of diagnosis overall, 30 days after diagnosis, and during 31 to 364 days and 0–10 years after diagnosis. Stratified Cox’s proportional hazards regression was used to compute hazard ratios. RESULTS: We identified a total of 1236 patients and 123,600 comparison cohort members. We observed that the standardized mortality rates of patients with advanced melanoma dropped from the 1980s onwards, but remain high (eg, 74.3 and 248.4 per 1000 person-years in 0–30 days and 31–364 days after diagnosis, respectively, for patients diagnosed during 2008–2011). Compared with the general population, patients with advanced melanoma had a 10.4-fold increased hazard of death during 0–10 years of follow-up. The highest relative mortality was found for the first year following melanoma diagnosis. No improvements in survival compared to the general population were observed in the most recent years of the study period, thus in 2004–2007 and 2008–2011. DISCUSSION AND CONCLUSION: Survival of patients with advanced cutaneous melanoma in Denmark improved between 1980 and 2013 but appears to have leveled off in the years leading up to more widespread introduction of newer immuno-oncology therapies.