P0707 - Clinical Characteristics and Outcomes of Appendiceal Neoplasms in Inflammatory Bowel Disease: A Tertiary Care Center Experience

Sunday, October 22, 2023

3:30 PM – 7:00 PM PT

Location: Exhibit Hall

Presenting Author(s)

Siri Urquhart, MD (she/her/hers)

Mayo Clinic
Rochester, MN

Siri Urquhart, MD, John Kisiel, MD, Nayantara Coelho-Prabhu, MBBS
Mayo Clinic, Rochester, MN

Introduction: Patients with inflammatory bowel disease (IBD), including ulcerative colitis (UC), Crohn’s disease (CD), and indeterminate colitis (IC), face increased risk for the development of colorectal dysplasia and carcinoma. Although appendiceal inflammation occurs histologically in 40-80% of colectomy specimens from patients with IBD, appendiceal neoplasms have been reported infrequently. A direct association between IBD and appendiceal neoplasia, including whether IBD predisposes to development of appendiceal neoplasia, is unclear.

Methods: Using bioinformatics and natural language processing tools to mine the electronic medical record at our large referral center, all patients > 18-years-old with IBD who had an appendiceal neoplasm were identified from January 1992 to April 2023. Relevant demographic and clinical data were abstracted.

Results: In total, 44 patients were included (61.4% female) with median age of 53 years at appendix neoplasm diagnosis. A majority had UC (68.2%). Of these, four (13.3%) had backwash ileitis, 27 (90%) had extensive colitis, 12 (40%) had a history of colorectal neoplasia (most common location and type included right colon and low-grade dysplasia, respectively), and 6 (20%) had primary sclerosing cholangitis (PSC). Median duration of IBD prior to appendix neoplasm diagnosis was 17 years. The most common type of appendix neoplasm was adenocarcinoma (36.4%). The most common presenting symptom associated with diagnosis of appendix neoplasm was abdominal pain/distension (36.4%). Appendix neoplasm diagnosis was made by cross-sectional imaging in a majority of patients (47.7%). All patients had appendix neoplasm surgically resected. Median appendix neoplasm size was 2.7 cm. Three patients with UC (6.8%) had recurrence after surgical resection due to peritoneal seeding with median time from initial diagnosis to recurrence of 78 months.

Discussion: Appendix neoplasms must be considered in patients with longstanding UC presenting with abdominal pain/distension. The most common types of appendix neoplasia included adenocarcinoma and appendiceal mucinous neoplasms. A minority of patients had metastatic disease at the time of appendiceal neoplasia diagnosis. Although the incidence and recurrence of appendix neoplasia in patients with IBD is relatively low, further studies to compare appendiceal neoplasia in patients with and without IBD are needed to determine if IBD predisposes to the development of this neoplastic complication.

	IBD subtype
	Crohn's disease (N = 13)	Ulcerative colitis (N = 30)	Indeterminate colitis (N = 1)
Age at appendix neoplasm diagnosis (y) Median (range)	52 (19-62)	55 (28-83)	53
Duration of IBD at time of appendix neoplasm diagnosis (y) Median (range)	11.5 (1 month to 35 years)^**	17.5 (29 days to 53 years)^**	8
Type of appendix neoplasm, n (%)	Adenocarcinoma 3 (23.1) Appendiceal mucinous neoplasm 4 (30.8) Carcinoid/neuroendocrine tumor 6 (46.2)	Adenocarcinoma 13 (43.3) Appendiceal mucinous neoplasm 11 (36.7) Carcinoid/neuroendocrine tumor 4 (13.3) Sessile serrated adenoma with low-grade dysplasia 1 (3.3) Unknown 1 (3.3)	Carcinoid/neuroendocrine tumor 1 (100.0)
Presenting symptom associated with diagnosis of appendix neoplasm, n (%)	Asymptomatic 3 (23.1) Abdominal pain/distension 6 (46.2) Metastatic disease 1 (7.7) Unknown 3 (23.1)	Asymptomatic 11 (36.7) Abdominal pain/distension 10 (33.3) Weight loss 1 (3.3) Two or more symptoms 1 (3.3) Unknown 7 (23.3)	Asymptomatic 1 (100.0)
Diagnosis of appendix neoplasm, n (%)	Endoscopy 0 (0) Cross-sectional imaging 7 (53.8) At time of surgery 5 (38.4) Unknown 1 (7.7)	Endoscopy 3 (10.0) Cross-sectional imaging 14 (46.7) At time of surgery 10 (33.3) Unknown 3 (10.0)	At time of surgery 1 (100.0)
IBD treatment at time of appendix neoplasm diagnosis, n (%)	5-ASA 1 (7.7) ^{^}Immunomodulator 1 (7.7) ^*Biologic 2 (15.4) ⁺Combination therapy 1 (7.7) No treatment 2 (15.4) Unknown 6 (46.2)	Corticosteroids 3 (10.0) 5-ASA 10 (33.3) ^{^}Immunomodulator 1 (3.3) ^*Biologic 2 (6.7) No treatment 6 (20.0) Unknown 8 (26.7)	Corticosteroids 1 (100.0)
Outcome of appendix neoplasm diagnosis, n (%)	Surgical resection 13 (100.0)	Surgical resection 30 (100.0)	Surgical resection 1 (100.0)
Appendix tumor size, (cm) Median (range)	1 (0.1-4.3)	3.4 (0.2-13.5)	1.5
Histologic tumor grade of appendix neoplasm, n (%)	Grade 1 - 6 (46.2) Grade 2 - 0 (0.0) Grade 3 - 1 (7.7) Grade 4 - 0 (0.0) Unknown - 4 (30.8)	Grade 1 - 8 (26.6) Grade 2 - 4 (13.3) Grade 3 - 1 (3.3) Grade 4 - 0 (0.0) Unknown - 12 (40.0)	Unknown 1 (100.0)
Lymph node involvement at time of appendix neoplasm diagnosis, n (%)	1 (7.7)	1 (3.3)	0 (0.0)
Metastatic disease at time of appendix neoplasm diagnosis, n (%)	1 (7.7)	6 (20.0)	0 (0.0)
Adjuvant chemotherapy, n (%)	2 (15.4)	10 (33.3)	0 (0.0)
Recurrence of appendix neoplasm, n (%)	0 (0.0)	3 (10.0)	0 (0.0)
Time to recurrence of appendix neoplasm (months) Median (range)	-	78 (7-91)⁺⁺	-

Table: Table 1. Appendiceal Neoplasm Characteristics and Outcomes
NOTE: Percentages were calculated on the basis of those with data available.
IBD, inflammatory bowel disease; 5-ASA, 5-aminosalicylate
**8 patients with Crohn's disease had their IBD diagnosed prior to appendix neoplasm diagnosis and 1 patient with Crohn's disease had their IBD diagnosis and appendix neoplasm diagnosis on the same date; all patients with ulcerative colitis had their IBD diagnosed prior to appendix neoplasm.
^Immunomodulator included azathioprine, methotrexate, or 6-mercaptopurine.
*Biologics included infliximab, adalimumab, certolizumab, natalizumab, vedolizumab, ustekinumab, and/or risankizumab.
+Combination therapy included corticosteroids and 5-ASA or biologic and immunomodulator such as azathioprine, methotrexate, or 6-mercaptopurine.
++3 patients with ulcerative colitis had recurrence of appendiceal neoplasm. All were not on IBD-directed therapy at the time of recurrence.

Disclosures:

Siri Urquhart indicated no relevant financial relationships.

John Kisiel: Exact Sciences – Consultant, Grant/Research Support, Intellectual Property/Patents, Royalties.

Nayantara Coelho-Prabhu: Alexion Pharma – Advisor or Review Panel Member. Iterative Health – Advisor or Review Panel Member.

Siri Urquhart, MD, John Kisiel, MD, Nayantara Coelho-Prabhu, MBBS. P0707 - Clinical Characteristics and Outcomes of Appendiceal Neoplasms in Inflammatory Bowel Disease: A Tertiary Care Center Experience, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.