Prognostic significance of tumor size for primary invasive cutaneous melanoma: A population-based study, 2004-2016

Abstract

Background: This study aimed to assess the independent prognostic value of tumor size compared with other clinical and pathologic features of primary invasive cutaneous melanoma (CM). Methods: This study included 28,593 patients with primary invasive CM in Surveillance, Epidemiology, and End Results Program database diagnosed from 2004 through 2016. Tumor size was divided into five subgroups (≤6, 7-12, 13-30, 31-42, and >42 mm). The primary endpoint was melanoma-specific survival (MSS). Results: The relationship between tumor size and survival was piecewise. After adjusting for age, sex, primary site, histopathologic cell type, Breslow thickness, ulceration, mitotic rate, regional metastasis, and distant metastasis, the hazard ratio (HR) of MSS increased with increasing tumor size until a peak at 31-42 mm (HRs, 1.33, 1.59, 2.41, respectively; all P 42 mm subgroup had the shortest MSS in T4. In addition, tumor size with a cutoff value of 12 mm showed stronger prognostic value for MSS (HR, 2.32; 95% CI, 1.80-2.98; P