Fernández-de-Misa Cabrera R, et al. - Patients with thin malignant melanoma (MM) staged according to both American Joint Committee on Cancer (AJCC) 7th and 8th editions were examined for differences in disease-free survival (DFS). Among 285 patients with cutaneous thin MM (thickness ≤1 mm), they noted an 8% shift of patients from a T1a towards a T1b stage group after applying the AJCC 8th edition. According to this 8th edition, T1a patients show significantly longer DFS than T1b patients; T1a and T1b had 5-year DFS of 100% and 95%, respectively. According to the AJCC 7th edition, T1a and T1b patients did not differ significantly regarding DFS; for T1a and T1b, 5-year DFS was 99 and 97%, respectively. These findings support better efficacy of the AJCC 8th edition as a tool for staging thin melanomas.