The small intestine is located between the stomach and the colon, and is approximately 15 feet long. As a part of the digestive system, it is concerned with the digestion of food and the absorption of nutrients. The cancer of this part of the digestive system is quite rare, but can occur at times.
There are basically five subtypes of this cancer, and these are known as adenocarcinoma, sarcoma, gastrointestinal stromal tumor, carcinoid tumors, and lymphoma. It has been observed that adenocarcinomas are more frequent in industrialized nations, while lymphomas are more common in developing countries.
What exactly causes this cancer is not known. However, some possible risk factors for this condition have been identified. Some such important risk factors for this cancer, especially for adenocarcinomas are, Crohn’s disease, celiac disease, and familial adenomatous polyposis.
Peutz-Jeghers syndrome and hereditary nonpolyposis colorectal cancer can also raise the risk of developing cancer of the small intestine. The lymphomas are more commonly observed to be associated with a weakened immune system and celiac disease. Apart from these, eating habits can play an important role in the development of this cancer. A high fat diet coupled with unhealthy eating habits may increase the risk of this cancer.
Signs and Symptoms
The symptoms of this cancer can be vague, especially in the early stage. Many of these symptoms can resemble the symptoms produced by certain other health conditions. Therefore, they cannot be termed as the specific symptoms associated with the cancer of the small intestine. Such symptoms can include:
- Abdominal cramps or pain that can be felt in the middle of the abdomen
- Loss of appetite
- Nausea and bloating
- A lump in the abdomen
- Unexplained weight loss
- Unusual fatigue
- Vomiting blood
- Presence of blood in stool, or black, tarry stool
The treatment and prognosis of this cancer depend on several factors, including the subtype and the stage at which it is detected. The main treatment options for this cancer are, surgery, chemotherapy, radiation therapy, and biological therapy. Surgery is the most common treatment option, and it can be of two types – resection and bypass surgery.
In the resection surgery, a section of the small intestine that contains the cancerous cells or the tumor is removed surgically. After the surgery, the cut ends of the intestine are reconnected. Bypass surgery is usually opted if the tumor causes a blockage in the small intestine.
In radiation therapy, high energy X-rays are used to destroy the cancerous cells. Radiation therapy can be external or internal. In external radiation therapy, radiation is sent from a machine outside the body, while in internal radiation therapy, a radioactive substance is placed near the cancerous cells with the help of needles or catheters.
Radiation therapy is sometimes given after surgery to kill the remaining cancerous cells. Chemotherapy is another treatment option, where some specific drugs are used to target the malignant cells. Chemotherapy drugs can be administered orally or they can be injected into a vein or muscle. Biological therapy, on the other hand, uses substances that can stimulate the immune system to destroy the cancerous cells.
The survival rate for this cancer can vary depending on the subtype. The chances of recovery are better, if the cancer has not spread outside the small intestine. If the cancer is limited to the inner wall of the small intestine, then the chances of survival are good. In general, the 5-year survival rate for adenocarcinoma is about 55%, provided the cancer has not spread beyond the small intestine. The early diagnosis can ensure prompt treatment of this cancer, and increase the chances of survival.