Elevated risk of multiple primary malignancies in esophageal cancer survivors: Incidence, patterns, and risk factors.

e16008 Background: Advancements in diagnostics and improved survival rates have raised a growing concern about the occurrence of multiple primary malignancies (MPMs) in survivors of esophageal cancer (EC). This study examines the incidence of MPMs in this population and explores potential risk factors to provide actionable insights that improve patient outcomes. Methods: Data from 56,756 EC patients in the SEER 17 registries (2000–2021) were analyzed. Standardized incidence ratios (SIRs) assessed MPM risk, and logistic regression identified key demographic and clinical predictors. Results: MPM risk was significantly elevated among EC survivors, particularly those with squamous cell carcinoma (SCC, SIR: 1.86) and adenocarcinoma (AC, SIR: 1.28). SCC survivors had the highest SIRs for MPMs in the trachea (57.60), esophagus (13.15), and oral cavity/pharynx (12.01). AC survivors had elevated risks in the esophagus (9.35), stomach (6.45), and thyroid (2.95). Key risk factors for MPMs included localized disease (OR: 3.25, CI: 2.89–3.65), race (Black: OR 2.36, CI: 2.10–2.65; White: OR 2.29, CI: 2.05–2.56; Asian/Pacific Islander: OR 2.19, CI: 1.88–2.55), surgical intervention (OR: 2.01, CI: 1.86–2.18), and age ≥65 years (OR: 1.90, CI: 1.48–2.50). Conclusions: Esophageal cancer survivors face a heightened risk of MPMs, driven by factors such as disease stage, race, surgical history, and age. These findings underscore the importance of personalized follow-up strategies and targeted interventions to mitigate risks and improve long-term outcomes.