Small Bowel Malignancies

Disclaimer

This manual is not a substitute for consultation with an appropriate specialist.
The contents of this manual have been developed through consensus of a Provincial Tumour Group. Please note the various update dates for each section as some of the content of the manual may not be up to date.

Small Bowel Malignancies

Malignancies that arise from the small intestine are quite rare. They include many histologic subtypes including: adenocarcinoma, lymphoma, sarcoma, and neuroendocrine tumours. This section addresses adenocarcinomas arising from the duodenum, jejunum and ileum. Please refer to the linked sections for management of all other subtypes.

1. Screening

Due to the rarity of malignancies arising from the small bowel, there are no recommended screening guidelines.

Hereditary/Genetic Syndromes:

Adenocarcinomas arising in both the small and large intestine are associated with a number of heritable cancer syndromes.
Please refer to the BC Cancer Hereditary Cancer Program (HCP) for description and indications for referral to HCP regarding:
Hereditary Colorectal Cancer
Familial Adenomatous Polyposis and other polyposis syndromes

2. Diagnostic and Staging Work-Up

Patients with small bowel neoplasms may present with any number of the following:

abdominal pain,
obstructive symptoms,
bleeding,
anorexia,
weight loss,
or in the case of a duodenal primary, jaundice.

Upper GI series with small bowel follow through may show a mass lesion, mucosal defect or intussusception.
CT scan of the abdomen and pelvis is generally done to assess the presenting symptoms and will reveal the extent of disease.
Upper GI endoscopy may detect a tumour in the duodenum and allow for biopsy for tissue diagnosis.
Wireless video capsule endoscopy is a means of visualizing the entire small bowel. However, it does not permit tissue sampling and should not be done in someone suspected of having bowel obstruction.
Exploratory laparoscopy or laparotomy may be required for diagnostic as well as therapeutic purposes.
PET scans are not recommended for staging purposes.
Pre-operative tumour markers: CEA, CA 19-9 and CA-125 may be useful for future monitoring.
Given the rarity of these cases, referral to BCCA is recommended.

3. Primary Surgical Therapy

For patients with localized adenocarcinomas of the small bowel wide segmental resection is done with curative intent.
Pancreaticoduodenectomy is required for tumours arising from the first and second portions of the duodenum.
A right hemicolectomy is indicated for tumours of the distal ileum.
For those with metastatic disease and no tissue diagnosis, biopsy for diagnostic purposes is essential. Palliative resection or bypass of the primary tumour may be done in patients with obstructive symptoms while patients with clinically significant active bleeding may require resection.

4. Pathology

(per College of American Pathologists 2012)

Specimen: specify

Type
Procedure Site

Tumour: specify

Site
Maximum tumour size
Histologic type
Histologic grade
Microscopic tumour extension
Margins: proximal, distal, mesenteric, circumferential
Lymph nodes: number examined, number involved
Lymph-Vascular invasion
Macroscopic tumour perforation
pTNM (AJCC 7th Edition)

Additional pathologic findings of interest
Histologic features suggestive of Microsatellite Instability

Intratumoral lymphocyte response
Prominent peritumoral lymphocyte response
Tumour subtype: mucinous, medullary, high histologic grade

Immunohistochemistry studies for Mismatch Repair Proteins

hMLH1
hMSH2
hMSH6
hPMS2

5. Staging

Staging diagram - small intestine

6. Treatment Options

Due to the rarity of these tumours, clinical trials are lacking, and most treatments are based on consensus opinion.

Resectable disease:

Resection of the primary and investing mesentery which contains the regional lymph nodes at risk for metastases provides important staging information.
Based on studies of patients with recurrent disease following complete resection, it is known that small bowel cancers tend to recur systemically. As such, extrapolating from published data for resected node-positive colon cancer, adjuvant chemotherapy with either 5-fluorouracil (5-FU) and oxaliplatin (i.e. FOLFOX) or 5-FU/capecitabine alone may be offered to patients (CAP approval required).
Patients with primary duodenal cancers are reported to be at higher risk of local recurrence. As such, adjuvant 5-FU-based chemoradiotherapy may be given in addition to a course of systemic chemotherapy.

Unresectable or metastatic disease:

Surgical resection and anastomosis or bypass of obstructing or bleeding primary tumours in selected patients
Endoscopic duodenal stent can be placed to palliate duodenal obstruction.
Palliative radiation therapy to the duodenum may provide local control.
Palliative chemotherapy with a 5-FU-based regimen in combination with a platinum compound has shown the best responses in retrospective studies. Any active regimen for either metastatic colon or gastric cancer would be a reasonable choice.

Options include (all require CAP approval):

5-FU and oxaliplatin (FOLFOX)
Epirubicin, cisplatin, and 5-FU or capecitabine (ECF/ECC)
5-FU and cisplatin (GIFUC)
5-FU and irinotecan (FOLFIRI)
infusional 5-FU alone (GIAVFL, GIFUINF)

The choice and sequence of chemotherapy is determined by disease-related factors, patient factors and patient preferences as assessed by the medical oncologist.

Consider treatment on a clinical trial, if available.
Symptom management, best supportive care, and involvement of palliative care services as indicated by patient's clinical status.

7. Follow-Up and Surveillance

Due to the rarity of malignancies arising from the small bowel, there are no recommended surveillance guidelines.

Patients with a small bowel adenocarcinoma are known to have a higher incidence of secondary malignancies involving the colon, rectum, ampulla of Vater, endometrium and ovary which warrants early investigation of any worrisome symptoms.