Late Breaking Abstract - Investigating the association between Elderly Onset Sarcoidosis and Malignancy: A Retrospective Comparative Cross-Sectional Study.

<bold>Introduction:</bold> Elderly-onset sarcoidosis (EOS) refers to sarcoidosis newly diagnosed in patients over 65 years old as the most commonly used cut-off age. We aimed to analyze the possible association between malignancy and the occurrence of sarcoidosis in elderly patients over 65 years old. <bold>Patients and methods:</bold> In this retrospective study, newly diagnosed sarcoidosis patients were categorized into two groups based on their age at first presentation: early onset (younger than 65 years) and elderly onset (over 65 years and older). Alongside demographic data, any previous history of malignancy before the diagnosis of sarcoidosis was obtained from the records. <bold>Results:</bold> Total number of 447 patients were included (Ealy-onset: 365 and elderly onset: 82 patients). The median age of the early onset group was 47Y (min-max: 23-63), compared to 69 Y (min-max: 65-84), p≤0.001. Female patients were more prevalent in the group of elderly onsets (54.9%) compared to early onset group (35.9%) with risk of 2.17 (95%CI: 1.3-3.5, p:0.002). Regarding the past history of malignancy, patients who had positive history of malignancy were more prevalent among elderly onset group (29.6%) Compared to early onset group (5%), [OR (95%CI): 8.1 (4.1-15.8), p≤0.001]. <bold>Conclusion:</bold> EOS is a rare form of sarcoidosis with limited data on risk factors. Our study found a significant association between elderly onset sarcoidosis and a history of malignancy, making it an important factor to consider in these patients.