Small bowel cancer is rare, representing less than 5% of digestive cancers. Its incidence is estimated at less than 23 cases per million individuals.

Adenocarcinoma is the most common form of small bowel cancer. This type of cancer forms from the glandular cells of the mucosa of the small intestine. The main symptom of the disease is blood in the stool, sometimes associated with abdominal cramps and vomiting. Diagnosis is based on imaging studies. Surgical removal is the best treatment option.

Definition and symptoms

About the small intestine

The digestive system is composed of several organs whose purpose is to transform ingested food into small molecules that can be assimilated by the body. Thus, the first step is to bring the food to the mouth in order to shred it through chewing and with the help of the teeth. The salivary glands are in charge of producing saliva that will mix with the ingested food and start digestion. It also helps the food to progress towards the esophagus and then the stomach.

Once in the stomach, the food is kneaded and degraded thanks to the gastric juices in order to form a mush: the chyme. Once this is formed, it begins its journey through the intestines.

Diagram showing the anatomy of the upper body - small intestine cancer

First, there is the small intestine, also called the "small intestine", a long, tubular organ that connects the stomach to the large intestine, and in which most digestion takes place. The small intestine makes up three-quarters of the digestive system and is the longest part of the digestive tract. Many of the nutrients that are essential for the body to function properly will enter the bloodstream at this point.

The small intestine is composed of three parts: the duodenum, the jejunum, and the ileum. Food that is partially digested in the stomach enters the duodenum with digestive juices and bile. The food then progresses into the jejunum where further decomposition takes place. The digested food finally passes into the ileum where absorption of nutrients continues.

The remaining contents continue to progress to the large intestine or colon. The remaining fluid and nutrients are absorbed, while the remaining solids are stored in the rectum awaiting expulsion via the anus.

What is small bowel cancer?

Small bowel cancer is a malignant tumor. In fact, the cells of the small intestine can sometimes undergo changes that make their growth and behavior abnormal. This is called a precancerous state. For the small intestine, the most frequent precancerous state is the adenomatous polyp. At this stage, the cells are not yet cancerous, but the risk of them becoming cancerous is significant.

Sometimes the modified cells in the small intestine become cancerous. Cancer in the glandular cells (cells that make up the lining of the small intestine) develops. This is called adenocarcinoma of the small intestine. It is the most common cancer of the small intestine.

However, other cancers can occur in the organ:

Neuroendocrine tumors that arise in the neuroendocrine cells of the small intestine;
Lymphoma is when cancer starts in the lymphatic tissue of the small intestine;
A sarcoma is cancer that starts in the wall of the small intestine.

Small bowel cancer affects men more often than women. Generally, patients are over 50 years old at the time of diagnosis. Nearly 45% of them are 70 years or older.

Several risk factors are mentioned, including certain digestive tract diseases such as Crohn's disease or celiac disease, or hereditary digestive diseases (e.g. familial adenomatous polyposis or FAP). The risk of developing cancer also increases with age.

What are the symptoms?

Small bowel cancer usually develops without symptoms. When symptoms do exist, they are not very specific and another cause is first suspected:

Pain in the abdomen;
Nausea;
Vomiting;
Weight loss;
Constipation or diarrhea;
Bowel bleeding;
Blood in the stool or black stool;
Fatigue and feeling weak.

Namely! The presence of these symptoms should lead to medical consultation.

In some cases, small intestine cancer can lead to serious complications such as bowel obstruction or intestinal perforation.

Diagnosis and treatment

How is small bowel cancer diagnosed?

Diagnosis of small bowel cancer: a medical device that goes into the intestine to check the diagnosis of small bowel cancer is based on a variety of medical imaging tests: ultrasound, radiology, and gastroscopy. A gastroscopy is an upper GI endoscopy.

Ultrasound

An ultrasound is a medical examination based on the use of ultrasound emitted by the probe of a device called an ultrasound scanner. Ultrasound is a beam of inaudible sound waves sent by the probe that reflect off the walls of the organs to be analyzed and produce an echo. The images are obtained thanks to the return of this echo. The reflected waves are then converted by a computer into several shades of gray to form the image.

An ultrasound takes an average of 10 to 30 minutes. The examination is painless and harmless (since it does not use X-rays). There is no need for the patient to be hospitalized and no need for anesthesia.

Radiography

An x-ray is a medical imaging test that allows you to see part or all of an area of the body. This examination requires the use of X-rays because of their ability to penetrate tissues to a greater or lesser extent depending on their density.

The examination itself lasts between 10 and 15 minutes under the supervision of the medical team.

Gastroscopy

A gastroscopy or endoscopy is an examination performed under local or general anesthesia using an endoscope (flexible tube equipped with a camera and a lamp). This instrument can also be used to take a sample (biopsy), remove a tumor or a foreign body or coagulate blood vessels (treatment to stop bleeding).

Please note! Endoscopy is sometimes performed by video capsule. A wireless, battery-powered capsule is swallowed by the patient and allows tumors in the small intestine to be visualized.

What is the treatment?

The first choice of treatment for small bowel cancer is the surgical removal of the tumors. However, the treatment is chosen according to the size and location of the tumor, the age and health of the patient, and the presence of any metastases. It may therefore also include radiotherapy and/or chemotherapy.

In the case of extensive cancer, radiation therapy is often combined with chemotherapy. Chemotherapy is also sometimes used before or after surgery. It should be noted that chemotherapy can be a palliative treatment when the cancer is too advanced.

Charline D., Doctor of Pharmacy