S310 The Iron Clue: Leveraging Anemia to Detect Early Colorectal Cancer in Young Adults: A Propensity-Matched Retrospective Analysis From the TrientX Database

Introduction: Colorectal cancer (CRC) is the third most common cancer worldwide, with early detection significantly improving outcomes. Iron deficiency anemia (IDA), present in ∼2.9% of CRC cases, may indicate early gastrointestinal blood loss and serve as the first clinical sign of malignancy. In adults aged 18–45 years, unexplained IDA is a relevant early marker of CRC and should prompt timely diagnostic evaluation, including endoscopy and colonoscopy. Early detection through endoscopic investigation enables the identification of malignancy or advanced neoplasia, reducing CRC-related morbidity and mortality. Methods: This 10-year retrospective cohort study utilized TriNetX data (2015–2024) and included adults aged 18–45, divided into 2 cohorts: those with IDA, defined by hemoglobin <13 g/dL and ferritin <30 ng/mL or <100 ng/mL with transferrin saturation <20%, and those without IDA. Patients with pregnancy, alternative causes of IDA, or a prior history of colorectal cancer (CRC) were excluded. Primary outcome: Incidence of CRC. Secondary: rates of colonoscopies, colonic polyps incidence and mean hemoglobin. Propensity score matching was performed to limit the confounders' effect. Results: A total of 357,680 patients were included, evenly divided into 2 cohorts of 178,840 each. The IDA group showed a significantly higher incidence of CRC, polyps, and colonoscopy utilization compared to the non-IDA group. Additionally, the mean baseline hemoglobin was significantly lower in the IDA group (11.8 g/dL ± 2.5) compared to the non-IDA group (13.0 g/dL ± 2.7). Conclusion: Patients with IDA had a 2.4-fold increased risk of developing CRC compared to matched controls without IDA. Anemic patients were more likely to have polyps and undergo colonoscopies than non-IDA individuals. These findings underscore the importance of heightened surveillance in patients with IDA where major causes have been ruled out. While the American Gastroenterological Association 2020 guidelines recommend endoscopic evaluation for IDA, our study analyzes the largest database to assess the actual rates of colonoscopy utilization and subsequent diagnosis in this patient population. Given the substantial burden of CRC and early detection associated with better prognosis, early incorporation of colonoscopy during IDA workup may improve early diagnosis and timely interventions in patients with CRC, ultimately improving patient outcomes.