Chemotherapy for Small Intestine Cancer (Adenocarcinoma)

Chemotherapy (chemo) uses drugs to kill cancer cells. Often, these drugs are injected into a vein (IV) or given by mouth. They enter the bloodstream and can reach cancer cells anywhere in the body.

Unfortunately, small intestine adenocarcinoma does not seem to be very sensitive to chemo, so it is not often part of the main treatment for this cancer. Still, it may be used in some situations:

• If the cancer has spread (metastasized) to other parts of the body
• After the tumor is removed with surgery (called adjuvant treatment), to try to lower the chance that the cancer will come back. It's not yet clear how well this works or small intestine cancer.
• As intraperitoneal chemotherapy for cancer that has spread to the inner lining of the abdomen (called the peritoneum). For this treatment, chemo is put directly into the abdomen right after surgery. The chemo is often heated first to help it work better. This is known as hyperthermic intraperitoneal chemotherapy (HIPEC).

Which chemo drugs might be used?

Some of the chemo drugs that can be used include:

• Capecitabine
• 5-fluorouracil (5-FU)
• Oxaliplatin
• Irinotecan

5-FU is often given with a vitamin-like drug called leucovorin, which helps it work better.

Because small intestine cancer is rare, it has been hard to study which chemo drugs work best. Some of the drug combinations that seem to work in advanced small intestine cancer include:

• Capecitabine and oxaliplatin (called CAPOX)
• 5-FU and leucovorin with oxaliplatin (FOLFOX)
• 5-FU and leucovorin with irinotecan (FOLFIRI).

Possible side effects

Chemo drugs kill cancer cells but also damage some normal cells, which can lead to side effects. These depend on the type and dose of drugs, and the length of treatment. Common short-term side effects might include:

• Nausea and vomiting
• Loss of appetite
• Loss of hair
• Mouth sores
• Diarrhea

Chemo can also damage the blood-making cells of the bone marrow, so you may have low blood cell counts. This can lead to:

• An increased risk of infection (from a shortage of white blood cells)
• Bleeding or bruising after minor cuts or injuries (from a shortage of blood platelets)
• Fatigue (tiredness) or shortness of breath (from a shortage of red blood cells)

Along with these, some other side effects can be seen with certain medicines, for example:

• Capecitabine or 5-FU (when given as an infusion) can cause hand-foot syndrome. This starts out as redness in the hands and feet, which can then progress to pain and sensitivity in the palms and soles. If it worsens, blistering or skin peeling can occur, sometimes leading to open, painful sores. These symptoms gradually get better when the drug is stopped or the dose is lowered, so it's important to tell your doctor when symptoms first come up.
• Oxaliplatin can often cause neuropathy (nerve damage). Symptoms can include numbness, tingling, and even pain in the hands and feet. It can also make you very sensitive to hot and cold, especially in the throat and esophagus (the tube connecting the throat to the stomach), which can make swallowing liquids painful. More information about neuropathy can be found in Peripheral Neuropathy Caused by Chemotherapy.
• Many of these drugs commonly cause diarrhea, but it can be particularly bad with irinotecan. If you get diarrhea while being treated with irinotecan, it needs to be treated right away – at the first loose stool – to prevent severe dehydration.

Most side effects tend to go away after treatment is finished. But some, such as hand and foot numbness, might last for a long time. Talk to you cancer care team about any side effects you have, because there are often ways to lessen chemo side effects. For example, drugs can be given to help prevent or reduce nausea and vomiting.