Long-Term survival across breslow thickness categories: Findings from a Population-Based study of 210,042 Australian melanoma patients

The prognosis of a patient with a primary cutaneous melanoma is known to be related to the Breslow thickness of their tumor. This study sought to determine long-term (30-year) survival rates for the four AJCC 8th Edition T-categories by analyzing Australian registry data for 210,042 melanoma patients diagnosed from 1982-2014. The 30-year incidence rates of death due to melanoma and non-melanoma causes (with 95% confidence intervals) were 7.1% (CI 6.9-7.3%) and 32.8% (CI 32.3-33.3%), respectively. For T2 melanomas, the corresponding rates were 21.6% (CI 21.0-22.3%) and 35.6% (CI 34.7-36.6%), for T3 melanomas 34.2% (CI 33.4-35.1%) and 39.6% (CI 38.5-40.8%), and for T4 melanomas 44.3% (CI 43.2-45.3%) and 39.6% (CI 38.3-41.0%). A plateau in melanoma-related deaths occurred in T4 patients after 20 years but there were ongoing melanoma-related deaths for the other T-categories beyond 30 years. A progressive rise in the risk of death from other causes occurred across all T-categories.