Factors Associated With Improved Survival Among Young Adult Melanoma Patients Despite a Greater Incidence of Sentinel Lymph Node Metastasis

Introduction: We sought to evaluate the factors that affect sentinel lymph node (SLN) metastasis and survival among young melanoma patients (≤30 y). Methods: The Sunbelt Melanoma Trial is a multi-institutional prospective randomized trial of patients aged 18 to 70 y. Statistical analyses were performed to determine if patients ≤30 y of age had a significantly different outcome in terms of SLN metastasis, disease-free survival (DFS), and overall survival (OS) compared to older patients. Results: The median age of the 3031 patients in this study was 50 y (range 18 to 77 y); the 315 patients (10.4%) ≤30 y old were compared with those >30 y old. Of the 1944 patients with follow-up, the median follow-up was 48 mo. On univariate analysis, younger patients were more often female (54.7% versus 40.9%, P < 0.0005), with tumors <4 mm thick (94.9% versus 89.4%, P = 0.001) without ulceration (80.3% versus 70.9%, P < 0.0005) or evidence of regression (93.8% versus 87.8%, P = 0.003), and were less likely to have lentigo maligna (0.0% versus 2.6%) or acral lentiginous (0.4% versus 3.1%, P < 0.0005) subtype. Patient age ≤30 was associated with SLN metastasis on univariate (24.6% versus 19.7%, P = 0.05) and multivariate (OR = 1.77, 95% CI = 1.26-2.49, P = 0.001) analyses. With a median follow-up of 48 mo, younger patients had a significantly improved 5-y DFS (86.2% versus 79.1%, P = 0.036) and OS (89.9% versus 80.1%, P = 0.010). On multivariable Cox regression analysis, however, age group was not a significant independent prognostic factor affecting DFS or OS. Conclusion: Despite a higher rate of SLN metastasis, patients ≤30 y old do not have a worse survival attributable to a more favorable clinicopathologic profile.