Duodenal cancers occur in the small intestine, and make up fewer than one in 10 GI tract cancers and about one in 100 of all cancers. They tend to occur in older people, usually in their 60s and 70s.
There are four main types of cancers that affect this region of the body:
- This cancer starts in the cells lining the small intestine, usually in the duodenum, which is the portion of bowel that connects to the stomach. Rarely diagnosed in its early stages, duodenal adenocarcinoma tends to grow and block the Sometimes, it has already spread to nearby organs at the time of diagnosis.
- Carcinoid tumour
- The most common type of cancer to affect this region of the GI tract, it is a neuroendocrine tumour (NET) which tends to grow slowly. Carcinoid tumours grow from cells of the diffuse neuroendocrine system, which consists of nerve cells scattered throughout the intestines and other organs, where they function as hormone-producing cells. In the intestine, they stimulate the digestive process. They also help control the release of digestive juices and how fast food moves in the GI tract, as well as the growth of other types of digestive cells.
- These tumours can start anywhere in the body, including in the small intestine. Lymphomas grow out of lymphocyte cells, the white blood cells that control immune response to infections.
- These cancers start in connective tissues such as muscle. The most common sarcomas in the intestine are known as gastrointestinal stromal tumours (GISTs).
Signs and symptoms of duodenal carcinoma will depend on the stage of the cancer. In the early stages, it might not present any symptoms. As the tumours grow and obstruct the bowel or affect other organs, they might produce abdominal pain, nausea, vomiting, weight loss, constipation, diarrhea, bleeding from the bowel, blood in the stool, and fatigue and weakness (which may be caused by anemia).
In order to diagnose this type of cancer, X-rays and CT scans are usually used, often followed by an endoscopy. This is used to identify the site of bleeding or to look for tumours. An endoscopy of the small intestine consists of a tube with a camera at the end that is inserted through the mouth and esophagus into the stomach and the duodenum, where the majority of tumours are found. If a lesion is discovered, a biopsy might be taken to determine what type of tumour it is.
Doctors may use laparotomy or laparoscopy to examine and collect biopsy samples from the small intestine when other procedures are unsuccessful. They use these procedures when there is a blocked intestine (bowel obstruction), a mass in the abdomen, or buildup of fluid in the abdomen (ascites).
Although most small intestine cancers look very similar to colon cancer, chromosomal and DNA studies have found differences that could eventually lead to more effective treatments. Researchers are studying treatment options involving chemotherapy or radiation therapy, either before surgery (neoadjuvant treatment) or after surgery (adjuvant treatment), in the hopes of improving outcomes. Other therapies, such as targeted therapy or immunotherapy, are also being developed to fight small intestine cancer.