TNF-alpha immunosuppressive use and future malignancy risk.

10558 Background: Tumor Necrosis Factor Alpha (TNF-a) inhibitors suppress the immune system in patients with systemic inflammatory conditions. Long term data assessing future cancer risk for these patients is not known. We assessed long term risk of malignancy in patients with Rheumatoid Arthritis [RA], Inflammatory Bowel Disease [IBD], Psoriasis [PS], and Ankylosing Spondylitis [AS], who were or were not exposed to a TNF-a inhibitor. Methods: This was a retrospective, cohort study conducted using electronic medical record data for patients with complete demographic and treatment data at Northwestern Medicine from years 1998 to 2020 (RA: n = 10763; IBD: n = 12106; PS: n = 1920; AS: n = 5103). Inverse Probability of Treatment Weighting (IPTW) was used to balance the distributions of age, race, gender, smoking status, and follow-up time across exposure groups within each inflammatory condition type. Relative risk (RR) of malignancy based on TNF-a exposure was assessed using logistic regression. Results: 2583 (24.0%) of RA, 2185 (18.0%) of IBD, 1811 (94.3%) of PS, 572 (11.2%) of AS patients had TNF-a exposure. Median follow-up for patients was 43 months. The RR for any cancer was higher for patients exposed to a TNF-a agent with rheumatoid arthritis (RR 1.121 (95% CI 1.02-1.23, p = 0.015) and psoriasis (RR 1.763 (95% CI 1.32-2.37, p < 0.001). The relative risk of any cancer was lower in patients exposed to a TNF-a agent with IBD (RR 0.858 (95% CI 0.78-0.94, p = 0.001). No significant difference in relative risk associated with TNF-a exposure was detected with ankylosing spondylitis (RR 0.929 (95% CI 0.8-1.08, p = 0.344). Conclusions: Patients with RA or PS and TNF-a exposure had higher RR of overall malignancy. Patients with IBD and TNF-a exposure had lower risk of overall malignancy. TNF-a immunosuppression may alter cancer risk differently based on the disease states for which it is being used. This information is critical when counseling patients on long term risk and screening strategies when considering TNF-a inhibition.