Section: Small bowel
Incidence
- 5% of all adenomas occur in duodenum
- Cancers of small bowel:
- NETs: 1/3rd
- Adenocarcinoma: 1/3rd
- Lymphomas: 1/6th
- Stromal tumours: 8%
- 20–40% of malignant small bowel tumours are adenocarcinoma
- Peak at 70 y/o
- Slight male predominance
Aetiology
- Similar adenoma-carcinoma sequence to colorectal cancer
- A Krazy Disease Process (AFP, KRAS, DCC, p53)
Associations
- FAP
- 50–90% of FAP patients
- Require close surveillance, depending on Spigelman score
- HNPCC
- Peutz-Jeghers
- CF
- Crohn’s
- Coeliac
Presentation
- Unlike adenomas, they are usually symptomatic
- Bleeding
- Obstruction (duodenal or biliary)
- Perforation
- Metastases
Differential
- Ampullary cancer
- Pancreatic head cancer
Staging
Tumour
- T1 = invades submucosa or lamina propria
- T1a = submucosa
- T1b = lamina propria
- T2 = invades muscularis
- T3 = through muscularis into surrounding tissue, but not through serosa
- T4 = through serosa, into adjacent organs
Nodes
- N1 = 1–2 nodes
- N2 = 3 or more
- Any nodes is automatically stage III disease
Spigelman staging
- Stratifies risk of adenocarcinoma in FAP patients with duodenal polyps
- Traditionally Spigelman 1–3 → endoscopic surveillance
- Stage 4 → prophylactic duodenectomy (Whipple or pancreas-preserving)
- Score may underestimate risk of adenocarcinoma (Sourrouille et al, DCR 2017)
- Presence of an ampullary abnormality was additionally predictive of HGD
- Recommended modifying score to take this into account
Workup
- OGD and biopsy
- EUS if concern for malignancy
- CTCAP
- PET if indeterminate CT
Management
- Neoadjuvant chemo if invasion into surrounding structures
- Minimal evidence to guide this
- But has shown promise in small studies
- Complete resection with regional lymphadenectomy — Whipple
- No standard adjuvant protocol
- FOLFOX or FOLFIRI (have been used for metastatic small bowel ca)
Prognosis
- Depends most on number of nodes involved
- Overall 5YS is 50%
- Stage 1 = 68%
- Stage 2 = 48%
- Stage 3 = 35%
- Stage 4 = 4%
- Worse than comparative stage colorectal cancer