Small intestine cancer

The small intestine is the part of the digestive system that connects the stomach with the large intestine. Its interior is lined by various cells that are responsible for both the secretion of substances necessary for digestion and the absorption of nutrients. When some of these cells become malignant, that is, they lose the control mechanisms that allow them to reproduce and die normally, a neoplasm or cancer of the small intestine occurs.

It should be said, however, that the majority of tumors that occur in the small intestine, between 75% and 90%, are benign. Most of the time these tumors do not produce symptoms and if they do they are usually due to intestinal obstruction or chronic bleeding. They are generally not treated unless they cause significant bleeding that can lead to anemia, in which case they will be removed surgically.

How is it produced?

Malignant tumors of the small intestine can be of different classes depending on the type of cells from which they are produced. Adenocarcinomas, derived from intestinal cells with the capacity to secrete substances, are the most frequent malignant tumors of the small intestine. They occur mainly at the level of the final part of the duodenum and the initial part of the jejunum and more frequently in people with intestinal polyps.

Intestinal lymphomas are usually non-Hodgkin's type. They are usually localized, with a single location, but sometimes they present as diffuse tumors throughout the small intestine, mainly the ileum. They are usually aggressive tumors that easily invade structures adjacent to the intestine. Its incidence is higher in people with celiac disease.

Sarcomas are rare tumors of the small intestine and appear mainly in the jejunum and ileum.

It is worth highlighting a type of intestinal tumors that are carcinoid tumors. These tumors originate from cells with hormonal secretion capacity that exist in the intestinal wall, so they not only produce digestive symptoms but also other derivatives of hormonal production, mainly serotonin. They can be seen in the appendix and rectum, but those that occur in the small intestine, more frequently in the ileum than in the jejunum or duodenum, are more aggressive and tend to metastasize to the liver.

Symptoms

Most tumors of the small intestine give symptoms due to the obstruction of the digestive tract that they cause, in such a way that they can cause chronic intestinal pain that is difficult to control, alterations in intestinal transit and sometimes intestinal obstruction. They can ulcerate and bleed, which can lead to chronic bleeding anemia. Sometimes they can cause nausea and vomiting.

Diffuse intestinal lymphomas can cause episodes of fever, impaired intestinal absorption, weight loss, and severe asthenia.

Carcinoid tumors, in addition to the possible intestinal obstruction that they can cause depending on their size, are characterized by very marked asthenia and by symptoms derived from hormonal secretion. The serotonin produced by these tumors causes increased intestinal secretion, increased peristalsis, decreased absorption, and increased fibrosis. This fibrosis usually affects the intestine and especially the right heart valves (pulmonary and tricuspid), which can lead to heart failure, sudden episodes of arterial hypotension (which are usually triggered by stress, alcohol or certain foods), telangiectasias and wheezing. The carcinoid syndrome is characterized by intense facial flushing, diarrhea and cardiac involvement, although it can be said that there are carcinoid tumors that do not cause these symptoms as they have minimal hormonal production.

Diagnosis

An intestinal tumor should be suspected in a patient with long-standing symptoms of intestinal obstruction, intestinal pain, asthenia, or dark stools. In addition to a physical examination, a blood test will determine if there is anemia. A test to detect occult blood in feces can also be performed.

The difficulty in diagnosing these tumors is that their location is not easily accessible. Imaging tests such as barium contrast X-ray or computerized axial tomography (CT) may not always be successful. Endoscopy will allow tumors to be seen as long as they are in an accessible area of ​​the small intestine. Nowadays, thanks to the endoscopic capsule, it is easier to obtain images of inaccessible areas.

A carcinoid tumor will be suspected when the patient presents symptoms of digestive symptoms compatible with a small intestine tumor and there is facial flushing or symptoms derived from cardiac valve involvement such as those described above. A serotonin derivative can be determined in urine, which in the event of a carcinoid tumor will be very high. Also, plasma serotonin levels may be elevated as well.

80% of carcinoid tumors have receptors in their cells for a substance, somatostatin. If a scintigraphy is performed using a radioactively labeled somatostatin analog, it will be possible to see how these tumors take up this substance.

It should be said that sometimes there is only digestive symptoms, so until the tumor is intervened and analyzed, it is not possible to discern what type of small bowel cancer it is.

Treatment

The main treatment option for small bowel tumors is surgery. In general, an attempt is made to perform a wide resection and remove the lymph nodes from the affected area in the same intervention.

If the tumor cannot be removed or has spread, palliative surgeries, such as intestinal diversions and isolations of the affected intestinal segment, may be chosen to avoid recurrent episodes of intestinal obstruction.

In the case of lymphomas, chemotherapy or radiotherapy is usually associated with surgical resection.

Carcinoid tumors that present symptoms derived from hormonal secretion usually have already given metastases, mainly liver, so surgical resection of the same is not recommended unless they are unique or very localized. Chemotherapy is usually associated with treatment, although they are not very sensitive to it.

In case of not being able to operate, the symptoms produced by carcinoid tumors will be controlled with octreotide, loperamide, antihistamines, bronchodilators or corticosteroids.

Precautionary measures

There are no specific preventive measures for small bowel tumors. At most, if you have chronic digestive symptoms, it is advisable to go to the digestive specialist as soon as possible.