Small Bowel Carcinomas Associated with Immune-Mediated Intestinal Disorders: The Current Knowledge

Area of Science:

• Gastroenterology and Oncology
• Pathology and Molecular Biology

Background:

• Small bowel carcinomas (SBC) are rare, often linked to hereditary syndromes or immune-mediated disorders like coeliac disease (CD) and Crohn's disease (CrD).
• CD-associated SBC (CD-SBC) and CrD-associated SBC (CrD-SBC) share an inflammatory origin but exhibit distinct phenotypes, molecular profiles, and prognoses.

Purpose of the Study:

• To review recent pathological and molecular findings in CD-SBC and CrD-SBC.
• To provide insights for clinical and therapeutic management of these rare cancers.

Main Methods:

• Literature review of pathological and molecular studies on SBC associated with CD and CrD.
• Analysis of tumor cell phenotype, microsatellite instability, beta-catenin expression, and prognostic factors.

Main Results:

• CD-SBC and CrD-SBC differ in tumor characteristics and prognosis, despite common inflammatory backgrounds.
• High tumor-infiltrating lymphocyte density and glandular/medullary histotype are positive prognostic indicators.
• Dysplasia adjacent to SBC shows distinct features in CD versus CrD, with rare Epstein-Barr virus associations noted in CrD.

Conclusions:

• Understanding the distinct pathological and molecular features of CD-SBC and CrD-SBC is crucial for patient care.
• Novel insights into these rare small bowel cancers can guide future therapeutic strategies.
• Further research into prognostic factors and potential viral associations may improve outcomes.