Duodenal cancer is a type of malignancy that develops in the duodenum, which is a part of the small intestine. A malignancy involves cancerous cells that can metastasize (spread to other sites or invade and destroy nearby tissues). The most common type of duodenal cancer is adenocarcinoma.
What Is the Function of the Duodenum?
The duodenum is the first of three segments of the small intestine; the other segments are the jejunum and the ileum. The duodenum receives food from the stomach and digestive juices from the pancreas and gallbladder.
The digestive juices begin the process of digestion in the duodenum, breaking down ingested food from the stomach so that nutrients can be absorbed in the small intestine.
Types of Duodenal Cancer
There are five different types of duodenal cancer.
Adenocarcinomas can be found in cells that make and release mucus or other fluids. A 2016 study found that 55.7% of all adenocarcinomas were of the small bowel. The tumors sometimes grow big enough to cause intestinal blockage (bowel obstruction).
Duodenal adenocarcinoma is considered a rare and fast-spreading cancer in your small intestine. Although the duodenum is the most common part of the small intestine for adenocarcinoma to develop, overall, duodenal cancer represents less than 1% of all cancers of the gastrointestinal (digestive) tract.
Sarcomas are a type of tumor that arises from bone or soft tissues of the body. Primary sarcomas of the duodenum (those arising from the duodenum) are rare. Other types of cancer, such as testicular sarcomas, can metastasize to the duodenum, but the occurrence of this type of sarcoma in the duodenum is not common.
Carcinoid tumors most often form in the gastrointestinal system, in the stomach and intestines, and may metastasize to other areas of the body.
Carcinoid tumors can result in a rare but serious condition called carcinoid syndrome, characterized by serious symptoms caused by too many hormones that impact several different body systems. Symptoms of carcinoid syndrome include flushing, diarrhea, and, less frequently, trouble breathing (dyspnea) and associated wheezing.
Gastrointestinal Stromal Tumors
Gastrointestinal stromal tumors form in the wall of the gastrointestinal tract, in the stomach and intestines.
Lymphomas are a type of cancer that originates in the immune system but can affect various parts of the body, including the gastrointestinal system.
Duodenal Cancer Symptoms
Notable symptoms of duodenal cancer do not often occur for some time after the cancer begins to grow. Symptoms may be very unclear, which, unfortunately, can result in a delayed diagnosis.
Finding cancer early on leads to better treatment outcomes. Many times it can be a few months or longer before duodenal cancer symptoms begin and the condition is diagnosed.
Common symptoms of duodenal cancer include:
- Abdominal pain or cramps in the middle of the abdomen
- Nausea and vomiting
- Acid reflux (gastroesophageal reflux)
- Unexplained weight loss
- Fatigue and weakness
- Intestinal bleeding (causing dark-colored stools)
- Anemia (low red blood cell count)
- Jaundice (yellowing of the skin and eyes)
- A lump in the abdomen
Some of the symptoms of duodenal cancer result from the tumor causing an intestinal obstruction. Other symptoms are due to the inability of the duodenum to properly absorb vitamins and nutrients, and yet others are caused by bleeding (such as anemia and blood in the stool).
Inconsistent, cramp-like pain in the abdomen—which may worsen after eating—is often the first sign that a person has duodenal cancer. As the tumor grows, it may block the passage of food through the small bowel. This contributes to an increase in abdominal pain. If the intestine becomes completely blocked, severe nausea and vomiting will occur.
A tumor may begin to bleed inside of the duodenum, which can lead to a low red blood cell count (anemia) and blood in the stools (which appears as black, tarry-colored stools). Symptoms of anemia include weakness and fatigue; it can even cause lightheadedness, and a person may pass out.
An emergency situation associated with duodenal cancer is a perforated intestine: this is a rare condition caused by the cancer. Symptoms include severe abdominal pain that comes on over minutes to hours, as well as nausea and vomiting.
Jaundice is rare, but it can occur when the tumor blocks the bile duct (the tubular structure that transports bile). When bile is unable to flow, it builds up in the bloodstream, causing yellow-tinged skin and eyes.
It is important to note that the symptoms of duodenal cancer could be caused by conditions other than cancer. But if you have symptoms, it’s important to seek medical advice as soon as possible, particularly if the symptoms do not go away.
Causes of Duodenal Adenocarcinoma
The risks and causes of different types of duodenal cancer can vary. Because adenocarcinomas are the most common type, this section pertains to duodenal adenocarcinoma.
Although there are some known risk factors for duodenal adenocarcinomas, the exact cause of duodenal cancer is not well understood. However, scientists do know about some underlying factors that contribute to the development of duodenal cancer.
For example, DNA changes inside of adenocarcinoma cells appear to enable the tumors to grow inside of the duodenum. Some of our genes work to control when a cell begins to grow and divide (these are called oncogenes), while other genes keep cell division under control, stopping growth to fix mistakes in the DNA (these are called tumor-suppressor genes).
Scientists have studied oncogenes and tumor-suppressor genes for some time and strongly suspect that these genes play a role in cancer development. Some of these gene changes accumulate over a person’s lifetime. This is one reason the risk of cancer increases as a person ages.
Some patients who develop duodenal cancer have hereditary gene changes that lead to an inherited increased risk. In addition to familial adenomatous polyposis, there are other additional inherited genetic syndromes that increase the risk of small bowel adenocarcinoma as well.
Although scientists know that many duodenal cancers involve specific gene changes, they aren’t sure exactly what causes these changes. Gene changes could be inherited, or possibly influenced by risk factors (such as drinking too much alcohol or eating a diet too high in red meat). However, some gene changes seem to have no specific cause.
According to the American Cancer Society, the risks for adenocarcinoma of the small intestine are increased with certain diet and lifestyle choices, as well as the presence of other conditions, including:
- Smoking and alcohol use (some studies showed an increased risk, but not all)
- Sex (the risk increases for men)
- Age (people in their 60s and 70s were found to be most at risk)
- Diet (risks may be increased with a high intake of smoked, salted foods or red meat)
- The presence of other conditions (such as celiac disease, Crohn’s disease, a history of colon cancer, or familial adenomatous polyposis).
It’s important to properly diagnose the type of duodenal cancer, as well as the stage of the cancer, so that the right type of treatment can be determined. Staging cancer is the process of finding out how far the cancer has spread, and to which locations in the body.
There are many different types of tests used to help diagnose cancer, as well as to identify the stage of duodenal cancer. These tests include the following.
- A history and physical examination: Your health care provider will check for lumps or any other unusual signs of disease, as well as to evaluate a person’s overall health status.
- Lab studies: These include blood counts and blood chemistry tests to check for anemia or other unusual lab results.
- Liver function tests: These are performed by taking a blood sample to look for evidence of liver damage caused by duodenal cancer.
- Endoscopy: This is procedure involving an instrument that is placed inside the body to check for abnormalities of the organs and tissues. There are several types of endoscopy tests.
- Laparoscopy: This is a surgical procedure involving a fiberoptic instrument that is inserted through the abdominal wall via a small incision to view the organs. Sometimes tissue is removed and sent to the lab for microscopic examination to check for cancer. This is called a biopsy.
- Upper GI series: This is a series of X-rays taken after barium (a liquid that coats the stomach and small bowel for better viewing of the organs) is swallowed.
- Computerized tomography (CT) scan: This imaging test takes a series of images inside of the body from various angles. Computerized X-ray images are produced that show very detailed pictures of different body parts. Some CT scans use a type of dye so that images of organs and tissues can be seen more clearly.
- Magnetic resonance imaging (MRI): This imaging test uses very strong magnetic fields and radio waves to produce a series of detailed images. An MRI can show some types of cancer that are otherwise undetectable by other imaging tests. MRI imaging is also better at detecting whether cancer metastasis has occurred in the bone or brain.
The treatment for duodenal adenocarcinoma is complete surgical resection (the surgical removal of all or part of an organ or other body structure) or a Whipple procedure (pancreaticoduodenectomy).
A surgical resection (more accurately described as a “segmental duodenal resection,” which is the removal of a segment of the duodenum) may be performed instead of a Whipple procedure. The choioce depends on several factors, including:
- The location of the tumor
- The size of the tumor
- The stage of the cancer
- Other organs or tissues involved (metastasis of the cancer)
- The general health condition of the patient
- Other factors
A pancreaticoduodenectomy, or Whipple procedure, involves surgical removal of several areas that are adjoining structures to the duodenum. The procedure is performed to lower the risk of duodenal cancer spreading to nearby structures, and includes:
- Removal of part of the pancreas
- Removal of the cancerous segment of the duodenum
- Removal of the gallbladder
- Removal of nearby lymph nodes
- Removal of part of the stomach (in some Whipple procedures, but not all)
A Whipple procedure is not a simple operation; it is a complex surgery and, in fact, is several procedures in one operation. After recovery from a Whipple procedure, your oncologist may order chemotherapy (a type of treatment that kills cancer cells).
Treatment for duodenal cancer may also include the following.
- Radiation therapy: The use of high-energy beams (such as radiation from X-rays) to kill cancer cells.
- Chemotherapy: Administration of drugs that kill cancer cells or stop the growth of cancer. The medication is usually given via intravenous therapy, but some types of medication can be taken by mouth.
- Biologic therapy: These generally newer medications utilize substances made by living organisms to treat cancer.
Some factors can influence the outcome of duodenal cancer treatment. The prognosis is considered a person’s likeliness of recovery after surgery or other treatment modalities. In the case of duodenal cancer, the prognosis is influenced by several factors. These include:
- The type of duodenal cancer (some types are more aggressive than others)
- Where the cancer is located
- Whether the cancer has metastasized to other places in the body (such as the liver) or invaded nearby tissues (like the lymph nodes)
- Whether the cancer can be completely removed
- How early the diagnosis was made and whether this is an initial surgery or the cancer has recurred
A systematic review published in 2016 looked at 11 different studies and compared the five-year survival rate for those who had duodenal adenocarcinoma with and without lymph node involvement.
Those without lymph node involvement (invasion of the cancer into the lymph nodes) had a 65% five-year survival rate. Those with lymph node involvement had a 21% five-year survival rate.
Coping with a disease such as duodenal cancer is not an easy undertaking. It’s important to reach out and get support to deal with the many aspects of going through a diagnosis and treatment of malignant cancer.
There are many resources available (both online and in-person), such as through the American Cancer Society. You can find a local or online group of others who are going through similar circumstances.
If a support group isn’t enough, you may also want to consider reaching out for professional help, such as from a therapist or counseling professional. This is particularly true if you are experiencing any signs or symptoms of depression.
Many people have walked the path of recovery from cancer while learning how to maintain a high quality of life. It’s important not to forget to do things that you enjoy. For example, do your best to stay active before and during cancer treatment
Perhaps most importantly, remember that you are not your disease: don’t get too attached to the label of being a cancer patient. Instead, see yourself as a cancer survivor.