Patient and Tumor Factors on Overall Survival in Spindle Cell Melanoma

Spindle cell melanoma (SCM) is a rare melanoma subtype characterized histologically by atypical, spindled, malignant melanocytes. SCM often presents in older patients and lacks typical cytologic markers, complicating diagnosis and frequently leading to advanced disease upon presentation. While some studies have documented SCM incidence, none have thoroughly examined the demographic, socioeconomic, and treatment factors influencing survival outcomes.

This study aims to investigate how demographic and clinical factors affect overall survival outcomes in SCM, providing updated data on demographic, socioeconomic, and tumor-related characteristics and treatment patterns.

This retrospective cohort study analyzed histologically confirmed spindle cell melanoma and mixed spindle cell melanoma cases diagnosed between 2004 and 2021. Patient demographic, socioeconomic, and clinical factors were collected, and multivariate Cox regression analysis was performed to determine the effects on overall survival.

Among 9,210 SCM cases, most were White patients (97.5%), male (65.2%), and located in metropolitan areas (85.7%). Males were more likely to receive treatment at academic centers and have higher comorbidity scores. The average age at diagnosis was 67.3 years (SD±15.1). SCM in head and neck regions showed a worse prognosis compared to extremity melanomas. Surgical intervention, received by 84.9% of patients, was associated with improved overall survival. The minority of patients who received radiation and chemotherapy (13.2% and 3.3%, respectively) were linked to increased mortality risk.

Age, sex, insurance status, treatment facility type, tumor location, and stage significantly influence SCM survival outcomes. The findings suggest that SCM's prognosis is closely tied to demographic and clinical characteristics, similar to other melanoma subtypes, supporting standard treatment protocols with surgical intervention as the primary approach. This large-scale study leverages comprehensive NCDB data, contributing to the literature gap in SCM's treatment and management.