While superficial spreading melanomas (SSM) are diagnosed as thinner lesions, nodular melanomas (NM) have a more rapid growth rate and are biologically more aggressive compared to other histologic subtypes.

To determine the difference in 5-year relative survival in patients with NM and SSM at the same Breslow depth and TNM stage.

A population-based cross-sectional analysis compared the 5-year relative survival of patients with NM and SSM using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER)*Stat software (version 8.2.1-8.3.5). Chi-square tests compared the proportions, and Kaplan-Meier method with Z-score compared 5-year relative survival.

For patients diagnosed between 2004-2009 5-year relative survival was lower in NM compared to SSM (53.7% vs. 87.3%, Z score -41.35, p < 0.001). Similarly, for patients diagnosed between 2010-2015, 5-year relative survival was lower in NM compared to SSM (61.5% vs. 89.7%, Z score -2.7078, p < 0.01). Subgroup analyses showed inferior survival in NM in T1b, and survival differences remained significant after excluding patients with nodal or distant metastases.

Five-year relative survival is worse in NM compared to SSM especially in T1b, T2a, and T2b melanomas. Melanoma subtype should be taken into consideration when making treatment recommendations.