P1190Association Between Medication and Cancer Incidence in Patients with Inflammatory Bowel Disease: A Population-Based, Nested Case-Control Study

Background Patients with inflammatory bowel disease (IBD) have an altered risk for intestinal and extraintestinal malignancies, influenced by chronic inflammation and potentially by IBD-specific therapies. We aimed to quantify the association between specific IBD medications and incident cancer in a large, nationwide cohort. Methods Using South Korea’s HIRA database (2007-2023), we conducted a nationwide, nested case-control study. From a source cohort of 66,392 patients with IBD, we identified 2,032 incident cancer “cases”, matching each 1:4 to 8,128 cancer-free IBD “controls” by age, sex, IBD type, and year of IBD diagnosis (Table 1). Medication use was assessed with a 365-day lag period. We calculated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) using conditional logistic regression. Results The malignancy association profiles of IBD medications were distinct and highly specific. Use of 5-ASA was associated with significantly lower odds of colorectal cancer (CRC) (aOR 0.19, 95% CI 0.06–0.68) (Figure 1); however, this association was stratified, significant in male patients and those with Crohn’s disease (CD), but not in females or those with ulcerative colitis (UC). Conversely, any use of immunomodulators confirmed a known association with higher odds of non-Hodgkin lymphoma (NHL) (aOR 2.05, 95% CI 1.12–3.75). Biologic therapies showed the most complex profile. While any use of biologics was associated with higher odds of overall malignancy (aOR 1.25, 95% CI 1.02–1.54), this association was critically stratified by sex: it was observed only in male patients (aOR 1.46, 95% CI 1.10–1.93) and not in females (aOR 0.99, 95% CI 0.69–1.41). A strong association was also found for CRC (aOR 2.76, 95% CI 1.61–4.74), an association that was further stratified by IBD type, being most pronounced in patients with UC (aOR 3.47) who also showed an associated higher odd for stomach cancer (aOR 2.89 Finally, odds appeared to increase with long-term concomitant therapy with an immunomodulator (aOR 1.77, 95% CI 1.17–2.66) but not in non-concomitant immunomodulator use with biologics. Conclusion This study confirms IBD medications have distinct, specific malignancy associations. 5-ASA was associated with lower odds of CRC, primarily in males and patients with CD. Immunomodulators were associated with higher odds of NHL. Biologic therapy was associated with higher odds of overall and CRC; this association was highly stratified, with the overall malignancy association confined to males and the gastrointestinal cancer associations (CRC, stomach) in patients with UC. These findings highlight the need for nuanced, risk-stratified cancer surveillance based on medication exposure, sex, and IBD type. References: 1. Beaugerie L, Itzkowitz SH. Cancers complicating inflammatory bowel disease. N Engl J Med. 2015;372(15):1441-1452. doi:10.1056/NEJMra1403718 2. Axelrad JE, Hashash JG, Itzkowitz SH. AGA Clinical Practice Update on Management of Inflammatory Bowel Disease in Patients With Malignancy: Commentary. Clin Gastroenterol Hepatol. 2024;22(7):1365-1372. doi:10.1016/j.cgh.2024.03.032 3. Murthy SK, Ahmed F, Pugliese M, et al. A Population-Based Matched Cohort Study of Extra-Digestive Cancer Incidence and Mortality in Individuals With and Without Inflammatory Bowel Disease. Aliment Pharmacol Ther. Published online November 11, 2025. doi:10.1111/apt.70439 4. Bonovas S, Fiorino G, Lytras T, Nikolopoulos G, Peyrin-Biroulet L, Danese S. Systematic review with meta-analysis: use of 5-aminosalicylates and risk of colorectal neoplasia in patients with inflammatory bowel disease. Aliment Pharmacol Ther. 2017;45(9):1179-1192. doi:10.1111/apt.14023 Conflict of interest: Dr. Seo, Jeongkuk: No conflict of interest Lee, Ju Won: No conflict of interest Kim, Kyuwon: No conflict of interest Jung, Sun-Young: No conflict of interest Choi, Chang Hwan: No conflict of interest