Small Intestine Cancer Early Detection, Diagnosis, and Staging

This test measures the different types of cells in your blood. It can show if you have anemia (too few red blood cells). This can happen if the tumor has been bleeding for a long time.

You may also have a blood test to check your liver function, because small intestine cancer can spread to the liver.

Tumor markers are substances that certain types of cancer cells make. For small intestine cancer, doctors may check the blood for tumor markers called carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9).

Blood tests for these tumor markers can sometimes suggest someone might have cancer, but they can’t be used alone to screen for or diagnose cancer. Not everyone with cancer will have a high tumor marker level, and people without cancer can sometimes have high levels for other reasons.

Tumor marker tests are used most often along with other tests during or after cancer treatment. They may help show how well treatment is working or provide an early warning that a cancer has returned.

A CT scan uses x-rays to make detailed cross-sectional images of your body. Unlike a regular x-ray, a CT scan creates detailed images of the soft tissues in the body.

CT scans are often done if you have abdominal (belly) pain to try to find the source of the problem. Although small intestine tumors may not always be seen well on a CT, these scans are good at showing some of the problems that these tumors can cause (such as an obstruction or perforation). CT scans can also help find areas of cancer spread.

CT-guided needle biopsy: If a biopsy is needed to check for cancer spread, this test can also be used to guide a biopsy needle into the mass (lump) to get a tissue sample to check for cancer.

Like CT scans, MRI scans show detailed images of soft tissues in the body. MRI scans use radio waves and strong magnets instead of x-rays.

MRI scans can sometimes be useful for people who may have a small intestine tumor, because they can show a lot of details in soft tissues.

For a PET scan, a slightly radioactive form of sugar (known as FDG) is injected into the blood and collects mainly in cancer cells. PET scans are generally done to help see whether the cancer has spread to other parts of the body, outside of the colon or rectum. However, they do not show whether cancer has spread to the brain.

For this test, you will be given a barium liquid to drink, and then x-rays are done to look at the upper part of the digestive tract (the esophagus, stomach, and first part of the small intestine).

To look for problems in the rest of the small intestine, a small bowel follow-through can also be done. This involves taking more x-rays over the next few hours as the barium passes through the intestines.

These tests often give good pictures of the first part of the small intestine (the duodenum), but the rest of the small intestine may be hard to see in detail. These tests were done more often before endoscopy was available.

Upper endoscopy (also called esophagogastroduodenoscopy or EGD) is used to look at the esophagus, stomach and duodenum (the first part of the small intestine). The endoscope is put in through the mouth and then passes through the esophagus, into the stomach, and then into the first part of the small intestine. If the doctor sees any abnormal areas, small pieces of tissue can be removed to be looked at under a microscope to see if cancer is present.

Most people are given medicine before the test to make them sleepy. If this is the case, you will usually need someone to take you home (not just a cab or rideshare service).

This test is helpful in looking at the first part of the small intestine. Other tests, such as capsule endoscopy and double-balloon enteroscopy, are needed to look at the rest of the small intestine.

This procedure does not actually use an endoscope. Instead, you will swallow a capsule (about the size of a large vitamin pill) that has a light and a very small camera. Like any other pill, the capsule goes through the stomach and into the small intestine. As it travels through the small intestine (usually over about 8 hours), it takes thousands of pictures. The camera sends the images to a device that you wear around the waist while going about your normal daily activities. The pictures can then be downloaded onto a computer, where the doctor can look at them as a video. The capsule passes out of the body during a normal bowel movement and is flushed away.

Most of the small intestine can't be viewed with an upper endoscopy because it is too long (about 20 feet) and has too many curves. Double-balloon enteroscopy gets around these problems by using a special endoscope that is made up of 2 tubes, 1 inside the other.

You are given intravenous (IV) medicine to help you relax, or even general anesthesia so that you are asleep. The endoscope is then inserted either through the mouth or the anus, depending on whether there is a specific part of the small intestine to be looked at.

Once in the small intestine, the inner tube, which is an endoscope, is pushed forward a small distance, and then a balloon at its end is inflated to anchor it. Then the outer tube is pushed forward to near the end of the inner tube and it is then anchored in place with a balloon. This process is repeated over and over, letting the doctor see the intestine a foot at a time.

This test can sometimes be helpful when done along with capsule endoscopy. An advantage of this test over capsule endoscopy is that the doctor can biopsy anything that looks abnormal.

Because you will be given medicine to make you sleepy for the procedure, usually someone you know will need to drive you home, not just a cab or rideshare service.

When a tumor is found during an endoscopy, the doctor can use biopsy forceps (pincers or tongs) through the tube to take small samples of the tumor. The samples are very small, but doctors can usually make an accurate diagnosis.

Bleeding after a biopsy is a rare but potentially serious problem. If bleeding becomes a problem, doctors can sometimes inject drugs that constrict blood vessels through the endoscope and into the tumor to stop the bleeding.

For some people, surgery is needed to biopsy a tumor in the intestines. This may be done if the tumor cannot be reached with an endoscope.

Sometimes CT scans or other imaging tests are used to guide a thin, hollow needle to biopsy tumors in other organs (like the liver) to see if they are cancer.

If the cancer is advanced, the cancer cells will probably be tested for specific gene and protein changes that might help tell if targeted therapy drugs could be options for treatment. For example, the cancer cells are typically tested for changes (mutations) in the KRAS, NRAS, and BRAF genes, as well as other gene and protein changes.

Intestinal cancer cells are also typically tested to see if they have high numbers of gene changes called microsatellite instability (MSI). Testing might also be done to check for changes in any of the mismatch repair (MMR) genes (MLH1, MSH2, MSH6, and PMS2) or the proteins they make.

Changes in MSI or in MMR genes (or both) are often seen in people with Lynch syndrome (HNPCC).

There are 2 possible reasons to test small intestine cancers for MSI or for MMR gene changes:

• To determine whether certain immunotherapy drugs might be options for treatment.
• To identify people who should be tested for Lynch syndrome. People with Lynch syndrome are at higher risk for some other cancers, so they are typically advised to get other cancer screenings. For example, women with Lynch syndrome may need to be screened for endometrial cancer. Also, if a person has Lynch syndrome, their relatives could have it as well, and may want to be tested for it.