A RECENT study has found that patients with primary cutaneous melanomas measuring between 0.8mm and 1.0mm in Breslow thickness face a significantly higher risk of melanoma-related death compared to those with thinner melanomas. This research, which analysed data from over 144,000 Australian patients diagnosed with thin melanomas between 1982 and 2014, suggests that a 0.8-mm Breslow thickness threshold could be crucial in guiding clinical decisions and patient care.
Melanomas, typically classified as “thin” when their Breslow thickness is 1.0mm or less, are often associated with a generally excellent prognosis. However, the study aimed to better understand the risk of death associated with specific Breslow measurements within this category. The results indicated that melanomas measuring 0.8 to 1.0mm had a significantly higher risk of melanoma-related death compared to those smaller than 0.8mm.
After an average follow-up period of 15 years, the corresponding 20-year melanoma-specific survival rates were 91.9% (95% CI: 91.6%–92.1%), 94.2% (95% CI: 94.0%–94.4%), and 87.8% (95% CI: 87.3%–88.3%), respectively. Multivariable analyses further confirmed that tumours in the 0.8-1.0mm range were associated with both a greater absolute risk of melanoma-related death (subdistribution hazard ratio: 2.92; 95% CI: 2.74–3.12) and a greater rate of melanoma-related death (hazard ratio: 2.98; 95% CI: 2.79–3.18) than thinner tumours (<0.8 mm).
Interestingly, the risk of death from nonmelanoma-related causes was found to be consistent across all Breslow thickness categories, suggesting that the increased mortality risk was specific to melanoma.
This study highlights the importance of the 0.8-mm threshold for melanoma treatment, potentially aiding clinicians in identifying patients at higher risk and improving their management.
Helena Bradbury, EMJ
Reference
Lo SN et al. Risk of death due to melanoma and other causes in patients with thin cutaneous melanomas. JAMA Dermatol. 2024; doi:10.1001/jamadermatol.2024.4900.
