The short answer
NCI counts five types of small intestine cancer and its treatment summary covers only two of them, adenocarcinoma and leiomyosarcoma. Surgery is the most common treatment; bypass, palliative radiation and trials follow when the tumor cannot be removed.
NCI lists five types of small intestine cancer: adenocarcinoma, sarcoma, neuroendocrine tumors, gastrointestinal stromal tumor and lymphoma. Adenocarcinoma is the most common.
NCI says surgery is the most common treatment, and that the surgeon will usually remove lymph nodes near the small intestine and check them for cancer.
When the tumor cannot be removed, NCI lists bypass surgery, radiation as palliative therapy, and clinical trials of radiosensitizers, new anticancer drugs or immunotherapy.
Neuroendocrine tumors, GIST and lymphoma have their own NCI treatment summaries, so general small intestine cancer information may not apply.
Choose how you want to understand this
The full explanation.
The short answer
Small intestine cancer is not one single disease. It covers several different cancer types. All of them start in your small intestine. These include adenocarcinoma, sarcoma, neuroendocrine tumors, gastrointestinal stromal tumors (called GIST), and lymphoma. Treatment differs a lot by type. Knowing exactly which type you have is the first, most important question to ask your team.
Adenocarcinoma
Adenocarcinoma is the most common type. When possible, surgery removes the tumor along with a margin of healthy tissue. Say the tumor cannot be fully removed. Other options come into play. These include bypass surgery, which reroutes your digestive tract around the blockage. Radiation therapy can relieve symptoms too. Clinical trials may combine radiation with chemotherapy or newer drugs, including immunotherapy.
Sarcoma (leiomyosarcoma)
For this type, surgery to remove the tumor is the preferred approach, when it is possible. If the tumor cannot be removed, treatment may combine bypass surgery with radiation therapy. Surgery, radiation, or chemotherapy may also be used together. This is mainly to ease symptoms, not to cure the cancer. Clinical trials testing new drugs and immunotherapy are another option worth asking about.
Neuroendocrine tumors, GIST, and lymphoma
These three types are treated differently enough that they have their own separate, detailed treatment guidelines. Say you have one of these. Ask your team to walk you through the specific approach for your type. Do not assume general small intestine cancer information applies directly to you.
How treatment is given
Surgery for small intestine cancer usually includes removing nearby lymph nodes. This lets your team check whether the cancer has spread. Radiation can be external, delivered by a machine outside your body. Sometimes it is combined with drugs called radiosensitizers. These make cancer cells more sensitive to radiation. Chemotherapy can be given as a pill or through a vein, depending on the specific drugs used.
Side effects worth knowing about
Surgery on the small intestine can affect digestion. It can also affect how your body absorbs nutrients, especially if a larger section is removed. Ask your team whether you will need any changes to your diet afterward. Radiation to the abdomen commonly causes nausea, diarrhea, and fatigue. Chemotherapy side effects depend on the specific drugs. They often include fatigue, nausea, and a temporary drop in blood counts that raises infection risk.
Which symptoms cannot wait
Are you on chemotherapy, by pill or by vein? Then a fever of 100.4°F (38°C) or higher is an emergency. Phone your care team straight away, whatever the hour, and go to an emergency room if you cannot reach them quickly. These drugs cause the drop in blood counts described above, and the CDC calls this fever a medical emergency. If you have had surgery or radiation alone, call your care team the same day for that temperature instead. Also call for severe abdominal pain, or vomiting that will not stop. The same goes for signs of a bowel blockage, such as an inability to pass gas or stool along with worsening belly pain. These need prompt evaluation, not a wait for your next scheduled visit.
Why a second opinion can help here
Small intestine cancers are rare. Treatment approaches are still evolving for some types, especially sarcoma and adenocarcinoma that cannot be fully removed. Because of this, a second opinion can help. Look for a center that regularly sees small intestine cancer. A conversation about clinical trials can be worth pursuing too, especially if your local team has treated few cases like yours.
What to ask your care team
- Which specific type of small intestine cancer do I have, and how does that change my options?
- Can my tumor be fully removed with surgery, and if not, what comes next?
- Are there clinical trials that fit my situation?
- What symptoms should prompt a same-day call rather than waiting for my next appointment?
Sources
Words to know
Tap any term to see what it means.
Common questions
Which types does the NCI summary actually cover?
Only two. NCI names five types found in the small intestine, but its treatment summary discusses adenocarcinoma and leiomyosarcoma. Gastrointestinal neuroendocrine tumors, GIST and lymphoma have separate NCI summaries.
What happens if the tumor cannot be removed?
NCI lists surgery to bypass the tumor, radiation therapy as palliative therapy to relieve symptoms, and clinical trials of radiation with radiosensitizers with or without chemotherapy, of new anticancer drugs, or of immunotherapy.
What is a radiosensitizer?
NCI describes radiosensitizers as drugs that make tumor cells more sensitive to radiation therapy, so that combining the two may kill more tumor cells. They appear in the trial options, not as standard care.
When should I ask about a clinical trial?
NCI notes that patients can enter trials before, during or after starting treatment, and that some trials are open only to people who have not started treatment. For unresectable disease, trials are on NCI's own option list.
Questions to ask your doctor
Being prepared helps you get the most out of your appointments. Save or print these questions.
Tap a question to save it to your list (kept on this device).
Your next step
Turn this guide into a short list for your care team.
Speak With Trained Specialists & Human Navigators
Cancer Explained provides educational guidance, but does not replace trained specialists, social workers, or your medical team.
Talk to a trained cancer information specialist
Free, confidential assistance from NCI Cancer Information Service via phone, chat, or email.
Contact your oncology team
Locate after-hours contact numbers, portal messages, or urgent triage phone lines.
Find a patient navigator
Get one-on-one help with appointments, logistics, translation, and care coordination.
Find a genetic counselor
Discuss inherited mutation risk, family history, and genetic testing options.
Find an oncology social worker
Access emotional counseling, family support groups, and mental health resources.
Find a financial navigator
Locate copay assistance foundations, grant programs, and lodging/travel support.
Find a clinical-trial specialist
Search matching studies and speak with NCI trial information specialists.
Get urgent help
Immediate emergency guidance for fever (>100.4°F during chemo), severe pain, or shortness of breath.
Help Us Improve This Guide
Did this explanation answer your question and help you determine your next step?
Know someone who needs this?
Plenty of people are looking for something like this and do not know where to start. If this would help a friend or someone you love, send it on — we have written an opening line so you do not have to stare at an empty message. You can change every word of it.
Your message is written and sent in your own email or messaging app — we never see who you send it to, and nothing is added to any list.
Plain-language explanation of the published sources cited on this page. AI-assisted, source-checked, not clinician-reviewed.
Sources last checked: 2026-08-13 what this meansLast updated: 2026-08-19Next planned review: 2027-01-22
How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status — Source checked. This page was written with AI assistance and checked line by line against the sources listed on it. That confirms the sources support what the page says. It is not a medical review, and it does not confirm the page is complete or right for your situation.
High-risk topic — talk to your care team. This topic can involve urgent, individual medical decisions. This page is general education only: it cannot tell you whether your situation is an emergency or what you personally should do. Follow your oncology team's instructions and contact them for individual guidance.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and checked line by line against the sources listed on it. That confirms the sources support what the page says. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
Read more about our editorial process, our use of AI, and our corrections policy.
Spotted a problem? Report an error — a factual mistake, broken or outdated source, confusing wording, or anything that seems unsafe. Please do not include names, medical record numbers, dates of birth, addresses, or other identifying medical information in your report.
After using this page, do you understand what to do next?
Anonymous — we only record the answer, never who gave it.
Related articles
Still have questions?
Educational answers, plain language
Free to print and share