Small Intestinal Cancer: Types, Symptoms & Treatment

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What is Small Intestinal Cancer?

Small intestinal cancer is a rare type of cancer that develops in the tissues of the small intestine (small bowel), which is a critical part of the digestive system. The small intestine connects the stomach to the large intestine and plays an essential role in nutrient absorption.

The small intestine is the longest part of the digestive tract, measuring approximately 3 to 6 meters (10 to 20 feet) in length in adults, depending on the individual. The exact length can vary based on factors such as age, sex, and overall body size.

It is divided into three sections:

Duodenum: The first part, about 25-30 cm (10-12 inches) long, connects to the stomach.
Jejunum: The middle portion, about 2.5 meters (8 feet) long, is responsible for most nutrient absorption.
Ileum: The final and longest section, approximately 3.5 meters (11 feet) long, ends at the large intestine

There are several types of small intestinal cancer, including:

Adenocarcinoma (most common): Begins in the glandular cells lining the small intestine.
Neuroendocrine tumours (including carcinoid tumours): Develop from hormone-producing cells.
Lymphoma: Cancer of the immune system cells in the intestinal walls.
Gastrointestinal stromal tumours (GIST): A type of sarcoma that begins in the connective tissues of the intestine.

Symptoms of small intestinal cancer may develop gradually and can vary based on the location and type of tumour. Common signs and symptoms include:

Abdominal pain (intermittent or persistent).
Unexplained weight loss.
Nausea and vomiting.
Fatigue or weakness (due to anaemia or malnutrition).

Changes in bowel habits (diarrhoea or constipation).
Visible or occult blood in stool (leading to black or tarry stools).
Bloating or feeling full quickly after eating.

The exact cause of small intestinal cancer is unknown, but several factors may increase the risk:

Age: It is more common in older adults.
Gender: Men are at a slightly higher risk.
Family history: A family history of colorectal or small bowel cancer.
Genetic conditions:
- Lynch syndrome (hereditary nonpolyposis colorectal cancer).
- Familial adenomatous polyposis (FAP).
- Peutz-Jeghers syndrome.
Chronic inflammation: Conditions like Crohn’s disease or celiac disease.
Dietary factors: A diet high in red meat, smoked foods, and low in fibre.
Smoking and alcohol use: These increase the risk of various cancers, including in the small intestine.
Weakened immune system: From conditions like HIV/AIDS or immunosuppressive therapy.

Diagnosis

Diagnosing small intestinal cancer involves a combination of clinical evaluation, imaging, and laboratory tests:

Medical History and Physical Exam

Assessment of symptoms and risk factors.
Palpation of the abdomen for masses or tenderness.

Imaging Test

CT scan: Detects tumours, blockages, or metastases.
Positron Emission Tomography (PET): Evaluates the spread of cancer and tumour metabolism.
Capsule Endoscopy/Enteroscopy: Direct visualisation of the small intestine using a camera attach to a capsule that swallowed by the patient.

Biopsy

A small tissue sample is taken during endoscopy, usually at the very proximal part of small intestine (duodenum or proximal jejunum) or the distal part (terminal ileum)

Blood Tests

Complete blood count (CBC): May show anaemia.
Tumour markers: Some cancers release specific markers (e.g., CEA or chromogranin A for neuroendocrine tumours).

Treatment

Treatment for small intestinal cancer depends on the type, stage, and overall health of the patient. Options include:

Surgery

The most common treatment for localised tumours.
Segmental resection involves removing the affected portion of the intestine and reconnecting the healthy parts.