Clinical Characteristics and Outcomes of Small Bowel Neoplasms in Crohn's Disease: A Tertiary Care Center Experience

Introduction: Small bowel (SB) cancer and associated death are more common amongst patients with inflammatory bowel disease (IBD) compared with the general population. Patients with Crohn’s disease (CD) who have ileal or any SB involvement are at increased risk of developing SB adenocarcinoma. Due the rarity of this fatal complication of CD, we aimed to describe the clinical features and presentation, outcomes, and incidence of SB neoplasms in patients with CD. 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 CD who had a SB neoplasm were identified from January 1992 to April 2023. Relevant demographic and clinical data were abstracted. Results: In total, 71 patients were included (39.4% female) with median age of 58 years at SB neoplasm diagnosis. A majority had ileal CD (49.3%) with stricturing (49.3%) phenotype. Twelve (16.9%) had perianal disease and 3 (4.2%) had upper gastrointestinal (GI) involvement. Thirty-six (50.7%) had history of SB stricture and 19 (26.8%) had history of IBD-related surgery prior to SB neoplasm diagnosis. Median duration of IBD prior to SB neoplasm diagnosis was 16 years. The most common type of SB neoplasm was adenocarcinoma (66.2%). The most common presenting symptom associated with diagnosis of SB neoplasm was obstruction (45.1%). SB neoplasm diagnosis was made at the time of surgery in a majority of patients (62%). Sixty-seven (94.4%) had SB neoplasm surgically resected. Median SB neoplasm size was 3 cm and was most often associated with a stricture (28.2%). Thirteen (18.3%) had recurrence of SB neoplasm with median time to recurrence from initial diagnosis of 26 months. Conclusion: Patients with IBD have increased risk for GI malignancies. Among these, the neoplasm with the highest relative risk and low overall survival is SB adenocarcinoma, although the absolute risk is low. Based on prior studies, risk factors for SB adenocarcinoma in CD include long disease duration, male sex, and stricturing disease. There are no specific recommendations for SB adenocarcinoma prevention and surveillance, except for control of inflammation. However, if patients develop a symptomatic stricture after prolonged symptom-free period or the stricture dose not respond to medical therapy, it is important to exclude early-stage cancer. Further studies with large sample sizes are needed to determine true incidence and risk factors associated with SB neoplasms in CD (Table 1). Table 1. - Small Bowel Neoplasm Characteristics and Outcomes Small Bowel Neoplasm (N = 71) Age at small bowel neoplasm diagnosis (y) Median (range) 58 (30-79) Duration of Crohn's disease at time of small bowel neoplasm diagnosis (y) Median (range) 16 (0 days to 53 years)* Type of small bowel neoplasm, n (%) Adenocarcinoma 47 (66.2)Carcinoid/NET 14 (19.7)Signet ring 7 (9.9)Metastatic disease from other primary** 3 (4.2) Location of small bowel neoplasm, n (%) Jejunum 10 (14.1)Ileum 57 (80.3)Ileocecal valve 4 (5.6) Presenting symptom associated with diagnosis of small bowel neoplasm, n (%) Obstruction 32 (45.1)Abdominal pain 21 (29.6)Weight loss 5 (7.0)Hematochezia 1 (1.4)Anemia 2 (2.8)Other+ 8 (11.3)Unknown 2 (2.8) Diagnosis of small bowel neoplasm, n (%) Endoscopy 11 (15.5)Cross-sectional imaging 13 (18.3)At time of surgery 44 (62.0)Unknown 3 (4.2) Crohn's disease treatment at time of small bowel neoplasm diagnosis, n (%) Corticosteroids 3 (4.2)5-ASA 5 (7.0)Immunomodulator^ 4 (5.6)BiologicY 5 (7.0)No treatment 5 (7.0)Unknown 49 (69.0) Outcome of small bowel neoplasm diagnosis, n (%) Surgical resection 67 (94.4) Small bowel tumor size, (cm) Median (range) 3 (0.3-25) Histologic tumor grade of small bowel neoplasm, n (%) Grade 1 - 11 (15.5)Grade 2 - 15 (21.1)Grade 3 - 22 (31.0)Grade 4 - 11 (15.5)Unknown - 12 (16.9) Small bowel neoplasm associations, n (%) Stricture 20 (28.2)Fistula 3 (4.2)Both 6 (8.5) Lymph node involvement at time of small bowel neoplasm diagnosis, n (%) 32 (45.1) Metastatic disease at time of small bowel neoplasm diagnosis, n (%) 29 (40.8) Adjuvant chemotherapy, n (%) 36 (50.7) Recurrence of small bowel neoplasm, n (%) 13 (18.3) Time to recurrence of small bowel neoplasm (months) Median (range) 26 (7-158) NOTE: Percentages were calculated on the basis of those with data available. NET, neuroendocrine tumor; 5-ASA, 5-aminosalicylate.*4 patients had same date of diagnosis for both Crohn's disease and small bowel neoplasm.**1 patient had metastatic endometrial cancer and 2 patients had metastatic breast cancer.+Other included asymptomatic, perforation, diarrhea, unresectable large polyp, appendicitis, and intra-abdominal abscess.^Immunomodulator included azathioprine, methotrexate, or 6-mercaptopurine. YBiologics included infliximab, adalimumab, certolizumab, natalizumab, vedolizumab, ustekinumab, and/or risankizumab.