S434 Risk Factors for Advanced-Stage Disease at Diagnosis in Colorectal Cancer

Introduction: According to American Cancer Society, at the beginning of colorectal cancer (CRC) screening era, an increase in local cancer and decrease in more advanced cancer were observed. However, this trend seems to have been reversed in recent years. We conducted this study to identify potential risk factors of advanced-staged disease at the time of CRC diagnosis. Methods: We retrospectively examined patients who were diagnosed with CRC in our institution and had a visit between July 2019 and March 2025. All patients with stage 0, I, and II CRC were included in non-advanced group, and patients with stage III and IV cancer were included in advanced group. Electronic medical record was reviewed and information on potential risk factors such as smoking status, lower gastrointestinal (GI) symptoms or anemia, fecal immunochemical test (FIT) results, and cancer genetics were collected. Univariate and multivariate logistic regression was performed to identify risk factors. Results: We identified 126 patients with non-advanced CRC and 184 patients with advanced CRC. Patients with advanced CRC were younger at diagnosis (60 vs 64 years old, P = 0.016) and more likely to be uninsured (26.6% vs 11.1%, P = 0.003). Significant risk factors found by univariate analysis include lower GI symptoms or anemia and KRAS mutation. In contrast, people who had diabetes, FIT within 1 year prior, positive FIT results within 1 year prior, and primary care physician (PCP) visit within 5 years prior are less likely to have advanced CRC. All potential risk factors or protective factors with a P value of <0.25 were included in multivariate analysis, which identified lower GI symptoms or anemia and KRAS mutation as significant risk factors for advanced-stage disease with odd ratio (OR) of 3.31 (95% confidence interval [CI], 1.47-8.04) and 28.5 (95% CI, 5.16-639), respectively. PCP visit within 5 years prior is a significant protective factor against advanced stage disease with an OR of 0.52 (95% CI, 0.29-0.91). Conclusion: Lower GI symptoms or anemia, KRAS mutation, and absence of primary care engagement are significant risk factors for advanced-stage disease at the time of CRC diagnosis. Other potential protective factors such as diabetes and prior screening also indicated better engagement in healthcare. Contrary to common beliefs, lifestyle modification such as smoking cessation and weight loss does not prevent advanced CRC. Actively enrolling patients in primary care clinic and detecting CRC before symptoms or anemia develop by screening tests can help with early diagnosis.