Epidemiology, survival, and prognostic factors of malignant eyelid tumors: A 17-year population-based study

Purpose: This study aimed to characterize the epidemiology, survival outcomes, and prognostic factors of primary malignant eyelid tumors, specifically sebaceous adenocarcinoma, malignant melanoma, and Merkel cell carcinoma (MCC). Methods: We conducted a retrospective analysis of 3,082 cases of primary eyelid malignancies diagnosed between 2004-2021 from the Surveillance, Epidemiology, and End Results (SEER) database. Patients were categorized by histological subtype, age, race, tumor stage, and treatment modality. Kaplan-Meier survival analysis, log-rank tests, and Cox proportional hazards regression were employed to evaluate survival and identify prognostic factors. Results: Sebaceous adenocarcinoma was the most prevalent subtype (26.57%), followed by malignant melanoma and MCC. Most patients (77.28%) were over 60 years old. While White individuals constituted the majority (86.9%), sebaceous adenocarcinoma showed a higher prevalence in Asian or Pacific Islander populations (11.8%). MCC exhibited the highest rate of distant metastases at diagnosis (19.4%). Surgery was the primary treatment (81.6%). Survival outcomes varied significantly by histology: MCC had the worst prognosis (5-year survival: 43.1%; median: 48 months), whereas melanoma had the best (5-year survival: 71.7%; median: 164 months). Cox regression identified age >60 years (HR: 4.25) and radiation therapy (HR: 2.01) as significant predictors of poor survival. Conclusion: Malignant eyelid tumors exhibit significant heterogeneity in survival. MCC is associated with the highest mortality, and advanced age and radiation therapy are key prognostic factors, underscoring the need for histology-specific management strategies.