P106 Small bowel adenocarcinoma in the setting of Crohn's disease: systematic review of the literature

Abstract

BACKGROUND: Small bowel cancer (SBC) is a rare entity that can be associated with Crohn's Disease. The incidence of SBC in patients with CD is increased by 18.75-fold compared to normal population. The pathogenesis of SBC in the setting of CD is not fully understood, but the disease has a poor prognosis due to diagnostic challenges associated with the primary disease. The aim of this study is to present 2 cases treated within a year in a high volume IBD center and to conduct a systematic literature review of small bowel adenocarcinoma (SBA) associated with small bowel CD. METHODS: Systematic literature review was done by using MEDLINE and EMBASE databases and data regarding demographics, presentation, diagnosis, treatment and survival were extracted. Articles that did not clearly state the location of the Crohn's disease and type of the cancer were excluded. RESULTS: We identified 216 patients diagnosed with small bowel adenocarcinoma in the setting of small bowel Crohn's disease from 117 studies. In this review obstruction was the most common initial symptom (n = 82, 59%; data are missing in 77 patients). Other common symptoms were abdominal pain (n = 12), anemia-bleeding (n = 11), diarrhea (n = 10), and fistulas (n = 5). there were 206 patients with one adenocarcinoma and 10 patients with 2 different adenocarcinomas. Among the patients with only one tumor, 154 patients (74.7%) were found to have ileal SBA. The median time to diagnosis of SBA from the diagnosis of CD was 18 months (1-300 months, data on 10 patients were missing). Out of 129, 64 patients (49.6%) were diagnosed with cancer after the surgical procedure whereas 46 patients (35.6%) were diagnosed intraoperatively and 15 (11.6%) were diagnosed preoperatively. Four patients (3.2%) were diagnosed at the autopsy without any surgical interventions and data were missing in 87 patients. 36.7% (18/49 patients) of the patients operated for obstruction were alive at one year, and 15.2% (7/46 patients) at 2-year. Although these percentages are lower than other studies reported in the literature, data was missing in 34 patients, so this might have affected the outcomes. CONCLUSION(S): Small bowel adenocarcinoma should be in the differential diagnosis in patients with longstanding ileal Crohn's disease presenting with small bowel obstruction, anemia, and perforation. Diagnosis and management of the small bowel adenocarcinoma in the setting of Crohn's disease is challenging and awareness and early diagnosis may avoid mortality.