A18: Association of Appendiceal Cancer with Autoimmune Disease

Friday, March 11, 2022

10:11 AM – 10:19 AM CST

Location: Coronado

Abstract Presenter(s)

Celyn Bregio

Medical Student
University of Chicago Pritzker School of Medicine
Chicago, Illinois, United States

Disclosure: I do not have any relevant financial / non-financial relationships with any proprietary interests.

Participants should be aware of the following financial/non-financial relationships:

Celyn Bregio: I do not have any relevant financial / non-financial relationships with any proprietary interests.

Introduction: Risk factors for the development of appendiceal epithelial neoplasms (AEN) (adenocarcinoma and low-grade appendiceal mucinous neoplasms (LAMN)) are poorly characterized. Recently, appendectomy has been linked to autoimmune manifestations; however, whether autoimmune diseases (AD) are associated with appendiceal neoplasms remains unknown. The appendix has a unique immunological environment that may be altered in AD, predisposing the tissue to neoplasia. We hypothesized that there is an epidemiological association of AEN with AD.

Methods: We retrospectively reviewed our single-center, prospectively collected database to identify patients with AEN between 2016 and 2021. Medical records were queried for clinical and pathologic data regarding any prior diagnosis of AD and the prevalence was ascertained. The comparison arm included age-matched cohort of patients seen at our medical center during the same time period, which was obtained using the Slicer Dicer program of EPIC medical systems. Chi-squared tests were used to determine heterogeneity with an alpha of 0.05.

Results: Of 134 patients with AEN, the percentage of those with AD was 22.4% (n= 30/134), while it was 2.32% in the age and sex matched cohort (n= 13,089/564,460) (p < 0.00001). Majority of the patients with AD were female in both groups (AEN (93.3%), matched cohort (83%)). Among patients with AD and AEN, the most common conditions were Hashimoto's thyroiditis (n = 20 (67%)), rheumatoid arthritis (n = 7(23%)), Graves' Disease (n = 5 (17%)), and ulcerative colitis (n =3 (10%)). There was no difference in the incidence of AD in patients with high-grade adenocarcinoma (22.7%, n=20) and LAMN (17.5%, n=10), p=0.34.

Conclusions:

This is the first study to identify the strong association between autoimmune disorders and appendiceal epithelial neoplasms. While this study does not demonstrate causality, this finding lends credence to the hypothesis that immune-related pathways may be implicated in the development of appendiceal disease. One postulated mechanism could be regional microbial dysbiosis driven by the defective immune system responsible for the autoimmune disease. Importantly, this study identifies AD as a risk factor for the development of AENs.

Learning Objectives:

Identify the potential association between appendiceal cancer and autoimmune disease.
Introspect into the potential role of immune-related pathways in the genesis of appendiceal cancer.
Distinguish the prospect for future investigations to identify possible new targets to treat appendiceal cancer.