Even though it is called the small intestine, it is actually the longest section of the gastrointestinal (GI) tract. The small intestine is about 15 to 20 feet long. Because of its length, to fit in the abdomen, the small intestine has many loops.The small intestine continues breaking down the food and absorbs most of the nutrients.
The small intestine has 3 sections. The first section is the duodenum. It is short, only about 8 inches long. It is directly attached to the stomach and is where the stomach empties its contents. A short distance from where it attaches to the stomach, the pancreatic duct and bile duct attach to the duodenum. These discharge bile and pancreatic juices into the duodenum to further the digestive process. They attach at a site called the ampulla of Vater
The next two sections of the small intestine are the jejunum and ileum. These parts of the intestine are where all the nutrients in food are absorbed into the bloodstream. They make up most of the length of the small intestine with the ileum being slightly longer. The duodenum continues as the jejunum. The ileum comes after the jejunum and ends when it empties into the large intestine (colon). The colon is a muscular tube about 4 to 5 feet long. The appendix is found near the place the ileum meets the colon. The colon continues to absorb water and mineral nutrients from the food matter and serves as a storage place for waste. The waste left after this process goes into the rectum. From there it passes out of your body through the anus.
These major types make up about 60% to 70% of small intestine cancers:
- Carcinoid tumors
- Sarcomas (including gastrointestinal stromal tumors)
- Adenocarcinomas make up about 30% to 40% of small intestine cancers. This type of cancer starts from the cells that line the intestine. Most experts think that cancer of the small intestine develops much like colorectal cancer. It first begins as a small benign outgrowth called a polyp. Over time, the polyp can change into a cancer. Most small intestinal cancers develop in the duodenum and the rest occur in the jejunum and ileum.
Depending on the type and stage of your cancer, you may need more than one type of treatment. Doctors on your cancer treatment team may include:
- A surgeon: a doctor who uses surgery to treat cancers or other problems
- A surgical oncologist: a doctor who treats cancer with surgery
- A radiation oncologist: a doctor who uses radiation to treat cancer
- A medical oncologist: a doctor who uses chemotherapy and other medicines to treat cancer
- A gastroenterologist: a doctor that specializes in diseases and problems of the digestive tract
After the small intestine cancer is found and staged, the cancer care team will suggest one or more treatment plans. Choosing a treatment plan is an important decision. It is also important for you to take time and think about all of your choices.
The main types of treatment used for small intestine adenocarcinoma are:
- Radiation therapy
The main factors in selecting treatment options for small intestine adenocarcinoma are the size and location of the tumor, whether it has spread to lymph nodes, liver, bones, or other organs, whether there are any other serious medical conditions, and whether the tumor is causing bothersome symptoms.
Other types of cancers of small intestines are treated with surgery and chemotherapy (lymphomas) or hormonal therapy (neuroendocrine tumours).