Small Intestine Cancer Treatment (Health Professional Version)

General Information About Small Intestine Cancer

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Incidence and Mortality

Estimated new cases and deaths from small intestine cancer in the United States in 2025:[1]

• New cases: 13,920.
• Deaths: 2,060.

Small intestine cancer types include adenocarcinoma, sarcoma, neuroendocrine tumors, gastrointestinal stromal tumors, and lymphoma. Small intestine cancer accounts for 3.8% of all digestive system malignancies.[1,2]

Follow-Up and Survivorship

As in other gastrointestinal malignancies, the predominant modality of treatment is surgery when resection is possible, and cure relates to the ability to completely resect the cancer.

Neuroendocrine tumors of the small intestine are covered in another summary as a separate cancer entity. For more information, see Gastrointestinal Neuroendocrine Tumors Treatment.

References

1. American Cancer Society: Cancer Facts and Figures 2025. American Cancer Society, 2025. Available online. Last accessed January 16, 2025.
2. National Cancer Institute: SEER Cancer Stat Facts: Small Intestine Cancer. Bethesda, Md: National Cancer Institute. Available online. Last accessed March 6, 2025.

Cellular Classification of Small Intestine Cancer

The following tumors occur in the small intestine:

• Adenocarcinoma (most cases).
• Lymphoma (uncommon), which is usually of the non-Hodgkin type. For more information, see Indolent B-Cell Non-Hodgkin Lymphoma Treatment, Aggressive B-Cell Non-Hodgkin Lymphoma Treatment, and Peripheral T-Cell Non-Hodgkin Lymphoma Treatment.
• Sarcoma (most commonly leiomyosarcoma and more rarely angiosarcoma or liposarcoma).
• Neuroendocrine tumors. For more information, see Gastrointestinal Neuroendocrine Tumors Treatment.
• Gastrointestinal stromal tumors. For more information, see Gastrointestinal Stromal Tumors Treatment.

Approximately 25% to 50% of the primary malignant tumors in the small intestine are adenocarcinomas, and most occur in the duodenum.[1] Small intestine carcinomas may occur synchronously or metachronously at multiple sites.

Leiomyosarcomas occur most often in the ileum.

About 20% of malignant lesions of the small intestine are neuroendocrine tumors, which occur more frequently in the ileum than in the duodenum or jejunum and may be multiple.

It is uncommon to find malignant lymphoma as a solitary small intestine lesion.

References

1. Small Intestine. In: Amin MB, Edge SB, Greene FL, et al., eds.: AJCC Cancer Staging Manual. 8th ed. Springer; 2017, pp. 221–34.

Stage Information for Small Intestine Cancer

The treatment sections of this summary are organized according to histopathological type rather than stage.

AJCC Stage Groupings and TNM Definitions

The American Joint Committee on Cancer (AJCC) has designated staging by TNM (tumor, node, metastasis) classification to define small intestine cancer. This staging classification applies only to adenocarcinomas arising in the nonampullary duodenum and small intestine. Nonadenocarcinomas arising in the small intestine should have a TNM assigned but are not assigned a stage classification.[1]

Table 1. Definitions of Primary Tumor (T)a

T Category	T Criteria
aReprinted with permission from AJCC: Small Intestine. In: Amin MB, Edge SB, Greene FL, et al., eds.: AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer, 2017, pp 221–34.
bFor T3 tumors, the nonperitonealized perimuscular tissue is, for the jejunum and ileum, part of the mesentery and, for the duodenum in areas where serosa is lacking, part of the interface with the pancreas.
TX	Primary tumor cannot be assessed.
T0	No evidence of primary tumor.
Tis	High-grade dysplasia/carcinoma in situ.
T1	Tumor invades the lamina propria or submucosa.
−T1a	Tumor invades the lamina propria.
−T1b	Tumor invades the submucosa.
T2	Tumor invades the muscularis propria.
T3	Tumor invades through the muscularis propria into the subserosa, or extends into nonperitonealized perimuscular tissue (mesentery or retroperitoneum) without serosal penetration.b
T4	Tumor perforates the visceral peritoneum or directly invades other organs or structures (e.g., other loops of small intestine, mesentery of adjacent loops of bowel, and abdominal wall by way of serosa; for duodenum only, invasion of pancreas or bile duct).

Table 2. Definitions of Regional Lymph Node (N)a

N Category	N Criteria
aReprinted with permission from AJCC: Small Intestine. In: Amin MB, Edge SB, Greene FL, et al., eds.: AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer, 2017, pp 221–34.
NX	Regional lymph nodes cannot be assessed.
N0	No regional lymph node metastasis.
N1	Metastasis in one or two regional lymph nodes.
N2	Metastasis in three or more regional lymph nodes.

Table 3. Definitions of Distant Metastasis (M)a

M Category	M Criteria
aReprinted with permission from AJCC: Small Intestine. In: Amin MB, Edge SB, Greene FL, et al., eds.: AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer, 2017, pp 221–34.
M0	No distant metastasis.
M1	Distant metastasis present.

Table 4. Prognostic Stage Groups for Adenocarcinomaa

Stage	T	N	M
T = primary tumor; N = regional lymph node; M = distant metastasis.
aReprinted with permission from AJCC: Small Intestine. In: Amin MB, Edge SB, Greene FL, et al., eds.: AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer, 2017, pp 221–34.
0	Tis	N0	M0
I	T1−2	N0	M0
IIA	T3	N0	M0
IIB	T4	N0	M0
IIIA	Any T	N1	M0
IIIB	Any T	N2	M0
IV	Any T	Any N	M1

References

1. Small Intestine. In: Amin MB, Edge SB, Greene FL, et al., eds.: AJCC Cancer Staging Manual. 8th ed. Springer; 2017, pp. 221–34.

Treatment of Small Intestine Adenocarcinoma

Treatment options:

1. For resectable primary disease:
   • Radical surgical resection.[1,2]
2. For unresectable primary disease:
   • Surgical bypass of obstructing lesion.
   • Palliative radiation therapy.
   • Clinical trials evaluating methods to improve local control, such as the use of radiation therapy with radiosensitizers with or without systemic chemotherapy.
3. For unresectable metastatic disease:
   • Clinical trials evaluating the value of new anticancer drugs and biological therapy (phase I and phase II studies).

Current Clinical Trials

Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.

References

1. Rose DM, Hochwald SN, Klimstra DS, et al.: Primary duodenal adenocarcinoma: a ten-year experience with 79 patients. J Am Coll Surg 183 (2): 89-96, 1996. [PUBMED Abstract]
2. North JH, Pack MS: Malignant tumors of the small intestine: a review of 144 cases. Am Surg 66 (1): 46-51, 2000. [PUBMED Abstract]

Treatment of Small Intestine Leiomyosarcoma

Treatment options:

1. For resectable primary disease:
   • Radical surgical resection.
2. For unresectable primary disease:
   • Surgical bypass of obstructing lesion and radiation therapy.
   • Clinical trials evaluating the value of new anticancer drugs and biological therapy.
3. For unresectable metastatic disease:
   • Palliative surgery.
   • Palliative radiation therapy.
   • Palliative chemotherapy.
   • Clinical trials evaluating the value of new anticancer drugs and biological therapy.

Current Clinical Trials

Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.

Treatment of Recurrent Small Intestine Cancer

Treatment options:

1. For metastatic adenocarcinoma or leiomyosarcoma:
   • No standard effective chemotherapy exists for patients with recurrent metastatic adenocarcinoma or leiomyosarcoma of the small intestine. These patients should consider enrolling in phase I or II clinical trials evaluating new anticancer drugs or biological therapy.
2. For locally recurrent disease:
   • Surgery.
   • Palliative radiation therapy.
   • Palliative chemotherapy.
   • Clinical trials evaluating ways of improving local control, such as the use of radiation therapy with radiosensitizers with or without systemic chemotherapy.

Current Clinical Trials

Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.

Latest Updates to This Summary (03/06/2025)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

General Information About Small Intestine Cancer

Updated statistics with estimated new cases and deaths for 2025 (cited American Cancer Society as reference 1).

Revised text to state that small intestine cancer accounts for 3.8% of all digestive system malignancies.

This summary is written and maintained by the PDQ Adult Treatment Editorial Board, which is editorially independent of NCI. The summary reflects an independent review of the literature and does not represent a policy statement of NCI or NIH. More information about summary policies and the role of the PDQ Editorial Boards in maintaining the PDQ summaries can be found on the About This PDQ Summary and PDQ® Cancer Information for Health Professionals pages.