Duodenal cancer is a rare type of cancer that forms in the first part of the small intestine. Symptoms can be vague, which can make early diagnosis difficult.
In this article, we look at what duodenal cancer is, along with its symptoms, diagnosis, and treatment. We also discuss survival rates for this type of cancer.
Duodenal cancer develops in the small intestine, which is part of the digestive system and connects the stomach to the colon.
The small intestine, or small bowel, is a long, folded tube that sits in the lower abdomen. It consists of three parts: the duodenum, the jejunum, and the ileum.
Duodenal cancer starts in the duodenum, which is the uppermost portion of the small intestine.
According to the American Cancer Society (ACS), there are four main types of small intestine cancer:
- Adenocarcinoma initially develops in the glandular cells that line the inside of the small intestine. Adenocarcinomas are the most common type of small intestine cancer, accounting for approximately 1 in 3 cases.
- Sarcoma begins in the muscle and other supporting tissues of the small intestine. Around 10 percent of small intestine cancers are sarcomas.
- Carcinoid tumors are slow-growing and develop in the neuroendocrine cells of the small intestine. Neuroendocrine cells produce hormone-like substances.
- Lymphomas form in cells called lymphocytes. These are part of the immune system and are present in most parts of the body, including the intestines.
This type of cancer is more common in older people, particularly in those aged over 60 years.
Small intestine cancer, including duodenal cancer, can cause a variety of symptoms, such as:
- unexplained weight loss
- abdominal pain
- bloody stools
- a lump in the abdomen
- weakness and fatigue
- anemia, which is a low number of red blood cells
- jaundice, which causes the skin and the whites of the eyes to become yellow
However, having these symptoms does not mean that a person has cancer. A range of conditions can cause similar symptoms, including irritable bowel syndrome and inflammatory bowel disease.
As these symptoms can suggest several different health conditions, a person should consult a doctor as soon as they appear.
A number of factors can increase a person’s risk of developing cancer.
Risk factors for developing a type of small intestine cancer, such as duodenal cancer, include:
- Age. Small intestine cancer is more common in older people.
- Inherited conditions. These are health issues that a person inherits from a parent. Those that may increase the risk of developing small intestine cancer include:
- familial adenomatous polyposis
- Lynch syndrome
- Peutz-Jeghers syndrome
- cystic fibrosis
- Gastrointestinal disorders. Having Crohn’s disease or celiac disease can increase the risk of cancer in the small intestine.
- Colon cancer. Having had colon cancer can increase the risk of developing small intestine cancer.
- Smoking and alcohol. The ACS report findings suggesting that people who smoke or drink alcohol may have an increased risk of small intestine cancer. However, confirming this as a risk factor will require further research.
- Diet. Some studies indicate that people who eat a lot of red meat, salt, or smoked foods may have a higher risk of small intestine cancer, according to the ACS.
It can be difficult for doctors to diagnose duodenal cancer, due to the natural folds of the small intestine and because symptoms can be similar to those of several other conditions.
To make a diagnosis, a doctor usually performs a physical exam to check the person’s general health and look for possible signs of disease. They will also ask about an individual’s medical history, including:
- health and lifestyle habits
- family history
- previous and current conditions
- current medications and ongoing treatments
To diagnose and correctly identify the stage of duodenal cancer, a doctor may order one or more tests, including:
- Blood tests. These involve taking a blood sample from the person and using it to check for signs of cancer and to help rule out other conditions.
- Imaging tests. These create images that allow the doctor to look inside the body for tumors and determine how far the cancer has spread. Imaging tests can include X-rays and MRI and CT scans. Some may require the person to drink a special dye.
- Upper endoscopy. During this procedure, a doctor inserts a thin, flexible tube called an endoscope through a person’s throat, then through the stomach and into the duodenum. The endoscope has a light and camera on the end, which allow the doctor to see and photograph problematic areas.
- Biopsy. During an upper endoscopy, a doctor can use the endoscope to take a sample of any potential tumors. They will then examine this sample under a microscope to check for signs of cancer.
- Capsule endoscopy. The doctor asks the person to swallow a small capsule that has a light and a camera inside. As the capsule moves along the duodenum and other portions of the small intestine, it sends pictures of its surroundings to a recorder connected to a computer.
Doctors usually stage duodenal cancer when they diagnose it. The stage reflects how far a person’s cancer has spread.
There are five stages for cancers of the small intestine: from stage 0 to stage 5. In the earliest stages, the cancer is confined to the place where it first developed. The later the stage, the further the cancer has spread into other areas of the body.
The stage of duodenal cancer can affect a person’s treatment options and outlook.
When a doctor diagnoses a person with duodenal cancer, the treatment options will depend on the cancer’s stage.
Usually, doctors first recommend surgery to remove the tumor. This is the main treatment for duodenal cancer.
A person may require different treatments:
- after surgery to kill any remaining cancerous cells and to prevent the cancer from returning
- instead of surgery, if the cancer is at an advanced stage
- instead of surgery, when a person cannot undergo an operation
Nonsurgical treatment options for duodenal cancer can include:
- Radiotherapy. This uses focused, high-energy beams, such as X-rays, to kill cancer cells. Doctors often administer this externally, using a machine.
- Chemotherapy. This involves taking medications that kill cancer cells or prevent them from growing. Administration is either oral or by intravenous injection.
- Biologic therapy. In this type of treatment, doctors use biological molecules to stimulate a person’s immune system to fight the cancer more effectively. Biologic therapy is new, and it may only be available by taking part in a clinical trial.
For duodenal cancer, a person’s outlook can depend on several factors, including the stage of the tumor at diagnosis.
Because its symptoms can be vague and similar to those of other, less serious conditions, doctors often diagnose duodenal cancer at later stages.
When they detect and treat the cancer at an early stage, the person’s outlook is generally better.
According to the American Society of Clinical Oncology, the 5-year relative survival rate for all types of small intestine cancer is 67 percent. This means that, following a diagnosis of small intestine cancer, a person is 67 percent as likely to live for at least the next 5 years as someone without the condition.
However, if a doctor diagnoses the cancer at an early stage, the survival rate increases to 83 percent.
If the cancer has spread to surrounding tissues and organs by the time of diagnosis, the 5-year survival rate is 73 percent. If the cancer has spread to distant parts of the body, the same survival rate is 43 percent.
It is important to note that these figures are just estimates, and doctors have based them on data that is at least 5 years old. Everyone’s outlook is different, and treatments for cancer are continuing to improve.
Duodenal cancer is rare, and it develops in the duodenum, which is the first section of the small intestine. The symptoms are often vague and can be similar to those of other conditions. This can make diagnosing the cancer in early stages difficult.
However, early diagnosis and treatment can significantly improve a person’s outlook, so it is important to see a doctor about any unexplained symptoms, such as weight loss or abdominal pain.