Melanoma Mortality Rises at 0.8-mm Breslow Thickness, Study Finds
Source: Medscape, December 2024
TOPLINE:
The risk for melanoma-related death was higher in individuals with tumors with a Breslow thickness of 0.8-1.0 mm than in individuals with tumors smaller than 0.8 mm, in an Australian study that used registry data.
METHODOLOGY:
The study analyzed 144,447 individuals (median age, 56 years, 54% men) diagnosed with thin (T1) primary invasive melanomas (Breslow thickness, ? 1.0 mm) between 1982 and 2014 from all eight Australian state and territory population-based cancer registries.
The researchers evaluated the associations between Breslow thickness (< 0.8 mm vs 0.8-1.0 mm) and incidences of melanoma-related and nonmelanoma-related deaths.
The primary endpoint was time to death attributable to a melanoma-related cause, with death due to a nonmelanoma-related cause as a competing event.
TAKEAWAY:
The 20-year cumulative incidence of melanoma-related deaths was 6.3% for the whole cohort. The incidence was higher for tumors with a thickness of 0.8-1.0 mm (11%) than for those with a thickness < 0.8 mm (5.6%).
The overall 20-year melanoma-specific survival rate was 95.9%, with rates of 94.2% for tumors < 0.8 mm and 87.8% for tumors measuring 0.8-1.0 mm in thickness. Each 0.1-mm increase in Breslow thickness was associated with worse prognosis.
A multivariable analysis revealed that a tumor thickness of 0.8-1.0 mm was associated with both a greater absolute risk for melanoma-related deaths (subdistribution hazard ratio, 2.92) and a higher rate of melanoma-related deaths (hazard ratio, 2.98) than a tumor thickness < 0.8 mm.
The 20-year incidence of death from nonmelanoma-related causes was 23.4%, but the risk for death from these causes showed no significant association with Breslow thickness categories.