Trends in the Incidence of Rare Eyelid Malignancies: A Surveillance, Epidemiology, and End Results-Based Study (2000-2021).

Introduction: Malignant eyelid tumors, despite being rare, are on the rise, especially in the older population, with risk factors including ultraviolet light exposure. Trends have been notable to be different among different genders, races, age groups, etc. Therefore, analyzing temporal trends in the incidence of eyelid cancers, including malignant melanoma (MM), Merkel cell carcinoma (MCC), and sebaceous gland carcinoma (SGC), and predicting future patterns would definitely improve our understanding of the disease. Methods: A retrospective study was conducted on the Surveillance, Epidemiology, and End Results (SEER) database spanning 2000-2021. Time series models were applied to estimate incidence rates (IRs) per 100,000. The best models were selected based on root mean square error (RMSE) and Akaike information criterion. Poisson regression was used to assess the impact of gender and age ≥60 on IRs. Results: The autoregressive integrated moving average (ARIMA)(0,1,0) model (RMSE = 0.0144, Akaike information criterion = -100.23) showed an increasing overall trend in eyelid cancers IRs from 2000 to 2015, declining slightly until 2020 (IR = 0.1028), then rising again in 2021. The 10-year forecast predicts an increase to 0.13 (95% PI: 0.11-0.15). For MM, error, trend, seasonal (M,N,N) model indicated a gradual IR rise until 2010, followed by a decline, and subsequent rise to 0.068 in 2020; predicted to reach 0.081 (95% PI: 0.062-0.100) by 2022. For MCC, neural network autoregression (2,2) model showed IR stability (0.003-0.008), with a slight drop in 2021 (IR = 0.006), and predicted to decrease to 0.01 (95% PI: 0-0.01). For SGC, ARIMA(0,0,0) model demonstrated a decline in IR in 2011 (IR = 0.0192), increase until 2019, then decrease in 2021 (IR = 0.0246), with a predicted 10-year decrease to 0.026 (95% PI: 0.019-0.032). Poisson regression revealed that age ≥60 significantly increased IRR for both MM and SGC (17.0 and 25.4, respectively). Gender was nonsignificant for all three cancers. Conclusion: Incidence of eyelid cancers revealed variable temporal trends, with a slight overall increase projected. Age ≥60 is a strong risk factor, particularly for MM and SGC.