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Small Intestine Cancer

1. Disease Information

2026-07-15
Falcon MONDO:0000956 Model: Edison Scientific Literature 26 citations

1. Disease Information

1.1 Overview and current definition

“Small bowel cancer” (SBC) is a rare malignancy of the small intestine. A recent hereditary-syndrome-focused review defines SBC as comprising four main histologic types: adenocarcinomas, neuroendocrine tumors, stromal tumors (including GIST), and lymphomas (borsotti2025hereditarycolorectalcancer pages 1-2). In the same source, adenocarcinoma and neuroendocrine tumors are described as the most common subtypes, each representing approximately ~40% of SBC, emphasizing that SBC is better treated as a group of diseases rather than a single entity (borsotti2025hereditarycolorectalcancer pages 1-2).

1.2 Anatomic distribution

Across SBC broadly, the duodenum is the most frequently affected site (55–82%), followed by the jejunum (11–25%) and ileum (7–17%) (borsotti2025hereditarycolorectalcancer pages 1-2). In Lynch syndrome–associated small bowel cancers, nearly 50% occur in the duodenum (borsotti2025hereditarycolorectalcancer pages 12-14).

1.3 Synonyms and alternative names

Commonly used synonyms in the clinical literature include: - Small bowel cancer, small intestine cancer, small-bowel tumor(s) (in diagnostic guideline contexts) (pennazio2023smallbowelcapsuleendoscopy pages 8-9, pennazio2023smallbowelcapsuleendoscopy pages 21-21) - Histology-specific entities: small bowel adenocarcinoma (SBA), small intestinal neuroendocrine tumor (SiNET; “midgut NET”), small intestine GIST (borsotti2025hereditarycolorectalcancer pages 1-2, strosberg2024sequencingofsomatostatinreceptor–based pages 1-2, serrano20232023geisguidelines pages 1-3)

1.4 Key identifiers (ICD/MeSH/OMIM/Orphanet/MONDO)

1.5 Evidence source type

The information assembled here derives from aggregated disease-level resources (guidelines/reviews) and population-level registry analyses (SEER-based studies) rather than individual EHR case series (pennazio2023smallbowelcapsuleendoscopy pages 8-9, dasari2025epidemiologyofneuroendocrine pages 5-7, alvarez2024incidenceandsurvival pages 1-2).

2. Etiology

2.1 Disease causal factors and upstream causes

SBC etiology is heterogeneous and histology-dependent: - Hereditary cancer predisposition syndromes (e.g., Lynch syndrome, FAP, Peutz–Jeghers syndrome) substantially elevate risk and motivate surveillance strategies (borsotti2025hereditarycolorectalcancer pages 1-2, borsotti2025hereditarycolorectalcancer pages 12-14, macfarland2024pediatriccancerscreening pages 5-6). - Molecularly driven mesenchymal oncogenesis in GIST is dominated by gain-of-function KIT or PDGFRA receptor tyrosine kinase mutations, which are described as “crucial drivers” responsible for tumor initiation and evolution across disease course (serrano20232023geisguidelines pages 1-1).

2.2 Risk factors

2.2.1 Genetic risk factors (high-confidence)

2.2.2 Environmental/lifestyle risk factors

  • Not specifically extractable for SBC from the retrieved evidence in this run (gap). The sources obtained focused on hereditary syndromes, diagnostic workup, and histology-specific therapeutics.

2.3 Protective factors

  • Not specifically extractable for SBC from the retrieved evidence in this run (gap).

2.4 Gene–environment interactions

  • Not specifically extractable for SBC from the retrieved evidence in this run (gap).

3. Phenotypes (clinical presentation)

3.1 Common clinical presentations

A major diagnostic guideline (ESGE small-bowel capsule endoscopy / device-assisted enteroscopy) highlights that small-bowel tumors are most often detected during evaluation of “obscure small-bowel bleeding” or “unexplained iron-deficiency anemia”, while also noting that tumors account for only ~3.5–5% of such presentations—making these symptoms weak predictors on their own (pennazio2023smallbowelcapsuleendoscopy pages 21-21).

Additional “increased risk” contexts for underlying small-bowel tumors in that guideline include liver metastases from occult neuroendocrine tumors, advanced melanoma (stage IV), stage III melanoma with positive FOBT, and nonresponsive/complicated celiac disease (pennazio2023smallbowelcapsuleendoscopy pages 21-21).

3.2 Phenotype ontology (HPO) suggestions (not exhaustive)

Based on the documented presentations (bleeding/IDA) and typical small-bowel tumor consequences, useful HPO mappings include: - Iron deficiency anemia (HP:0001891) - Gastrointestinal hemorrhage / intestinal bleeding (e.g., HP:0002239) - Occult gastrointestinal bleeding (no single canonical HPO term; may map to GI hemorrhage + laboratory evidence)

Evidence for bleeding/IDA as key presentations is supported by guideline text (pennazio2023smallbowelcapsuleendoscopy pages 21-21).

3.3 Quality of life impact

  • Not directly quantified in the retrieved SBC-focused evidence; however, chronic bleeding/IDA implies fatigue, reduced functional capacity, and healthcare utilization (inference; not directly cited).

4. Genetic / Molecular Information

4.1 Causal genes (germline predisposition)

High-confidence germline predisposition genes for SBC include: - MLH1, MSH2, MSH6, PMS2, EPCAM (Lynch syndrome) (borsotti2025hereditarycolorectalcancer pages 12-14) - APC (FAP) (macfarland2024pediatriccancerscreening pages 4-4) - MUTYH (MAP) (borsotti2025hereditarycolorectalcancer pages 19-21)

4.2 Key somatic drivers and biomarkers by subtype

4.2.1 GIST (small intestine stromal tumor)

4.2.2 Small intestinal neuroendocrine tumor (SiNET)

  • SiNETs are commonly somatostatin receptor (SSTR)–positive, especially SSTR2 and SSTR5; a 2024 review notes that “most well-differentiated NETs express high levels of somatostatin receptors, particularly subtypes 2 and 5” (strosberg2024sequencingofsomatostatinreceptor–based pages 1-2). A separate review notes >70% of NET tumor cells overexpress SSTR types 2 and 5 (tan2024gastroenteropancreaticneuroendocrineneoplasms pages 8-9).

4.2.3 Small bowel adenocarcinoma (SBA)

  • SBA-specific somatic alteration frequencies were not retrieved in the accessible evidence for this run (gap). The registry-based SBA prognostic model indicates survival is often hampered by late diagnosis but does not detail genomic drivers (borsotti2025hereditarycolorectalcancer pages 1-2).

5. Mechanism / Pathophysiology

5.1 Mechanistic causal chains (subtype-oriented)

  • GIST: activating KIT/PDGFRA signaling drives oncogenesis; downstream effects include sustained proliferation and survival consistent with receptor tyrosine kinase activation pathways (serrano20232023geisguidelines pages 1-1).
  • SiNET: expression of SSTR2/SSTR5 provides a mechanistic basis for symptom control (hormone secretion) and tumor growth control with somatostatin analogs, and for targeted radionuclide delivery via PRRT (tan2024gastroenteropancreaticneuroendocrineneoplasms pages 8-9, strosberg2024sequencingofsomatostatinreceptor–based pages 1-2).

5.2 Ontology suggestions

GO biological process (examples)

  • Receptor tyrosine kinase signaling pathway (GO:0007169) (GIST driver context) (serrano20232023geisguidelines pages 1-1)
  • Cell proliferation (GO:0008283)
  • Neuropeptide hormone signaling pathway (GO:0007218) (NET functional biology; mechanistic mapping supported indirectly via SSTR emphasis) (strosberg2024sequencingofsomatostatinreceptor–based pages 1-2)

CL cell types (examples)

  • Interstitial cell of Cajal (GIST cell-of-origin concept; not directly cited in retrieved evidence—flag as gap)
  • Enteroendocrine cell / neuroendocrine cell (SiNET; not directly cited in retrieved evidence—flag as gap)

6. Epidemiology (recent statistics)

6.1 Overall frequency

SBC is described as accounting for ~2.3% of all digestive cancers in the general population (borsotti2025hereditarycolorectalcancer pages 1-2).

6.2 Neuroendocrine neoplasms of the small intestine (US SEER)

A 2025 SEER-based analysis reports a small intestine NET incidence of approximately 1.2 per 100,000, with mean age at diagnosis ~64 years and long median survival compared with many other metastatic cancers (dasari2025epidemiologyofneuroendocrine pages 5-7). The broader SEER-based analysis reports small intestine NET incidence ~1.41 per 100,000, and provides additional prevalence context for NETs overall (dasari2025epidemiologyofneuroendocrine pages 4-5).

6.3 Small intestine GIST (US SEER)

A 2024 SEER-based cohort study reports that incidence rates for small intestine GIST increased 2.7% annually (2000–2019), with the increase mainly in localized-stage tumors (alvarez2024incidenceandsurvival pages 1-2).

6.4 Survival (selected recent estimates)

7. Diagnostics

A key ESGE guideline update (published 2023; “Update 2022”) provides an evidence-based framework for small-bowel tumor evaluation: - SBCE is recommended as an initial diagnostic tool in suspected small-bowel tumors in the absence of stenosis or prior resection (pennazio2023smallbowelcapsuleendoscopy pages 8-9). - If imaging already demonstrates tumor suspicion, ESGE recommends device-assisted enteroscopy (DAE) over capsule endoscopy (pennazio2023smallbowelcapsuleendoscopy pages 8-9). - Biopsy sampling via DAE is required to resolve uncertain capsule endoscopy diagnoses (pennazio2023smallbowelcapsuleendoscopy pages 8-9). - For subepithelial masses, confirmation should be obtained using DAE and/or cross-sectional imaging, and cross-sectional imaging is recommended for staging and operability when diagnostic certainty is high (pennazio2023smallbowelcapsuleendoscopy pages 8-9).

Table (click to expand)
Modality When to use Typical presentations prompting workup Advantages Limitations / risks Key guideline or review points Citations
Small-bowel capsule endoscopy (SBCE/CE) First-line luminal evaluation when a small-bowel tumor is suspected and there is no evidence of stenosis or prior resection; also recommended in patients at increased risk of small-bowel tumors; preferred first-line method for hereditary-syndrome surveillance programs Obscure small-bowel bleeding, unexplained iron-deficiency anemia, suspected small-bowel tumor, surveillance in hereditary syndromes such as PJS/FAP/selected LS settings Noninvasive, outpatient, visualizes entire mucosa, high sensitivity, excellent safety profile; reported diagnostic yield up to 91% in hereditary surveillance settings Cannot biopsy or treat; may miss solitary proximal/protruding lesions; capsule retention about 1-2%; lesion size/location can be imprecise ESGE recommends SBCE as an initial diagnostic tool in suspected small-bowel tumors without stenosis; not recommended for follow-up of treated tumors due to insufficient data; in hereditary settings it is commonly the primary surveillance test (pennazio2023smallbowelcapsuleendoscopy pages 8-9, pennazio2023smallbowelcapsuleendoscopy pages 21-21, borsotti2025hereditarycolorectalcancer pages 2-4, pennazio2023smallbowelcapsuleendoscopy pages 4-5, borsotti2025hereditarycolorectalcancer pages 1-2)
Device-assisted enteroscopy (DAE; DBE/SBE/spiral) Use when imaging already suggests tumor, when tissue diagnosis is needed after SBCE, when therapeutic intervention is likely, or to confirm subepithelial lesions Positive SBCE, suspected mass needing biopsy, high polyp burden/polyps needing resection, obstructive symptoms, hereditary syndrome surveillance with actionable lesions Direct visualization, biopsy, tattooing, endoscopic therapy/polypectomy, route can be guided by prior SBCE More invasive, time-consuming, requires sedation/deep sedation, lower complete small-bowel examination rate than SBCE ESGE prefers DAE over capsule if prior imaging has demonstrated tumor suspicion; biopsy is required for uncertain capsule findings; DBE diagnostic yield improves substantially when preceded by positive SBCE (pennazio2023smallbowelcapsuleendoscopy pages 8-9, borsotti2025hereditarycolorectalcancer pages 1-2, borsotti2025hereditarycolorectalcancer pages 2-4, borsotti2025hereditarycolorectalcancer pages 4-5, pennazio2023smallbowelcapsuleendoscopy pages 4-5)
CT enterography / cross-sectional CT Complementary test when SBCE may miss protruding lesions or when extraluminal disease, staging, or operability assessment is needed; useful if tumor is suspected on symptoms or endoscopy Bleeding/IDA with concern for mass, suspected subepithelial lesion, concern for obstruction/stenosis, preoperative staging Evaluates mural/extramural disease, metastatic spread, operability; complements capsule limitations for masses Radiation exposure; less sensitive than mucosal endoscopy for subtle superficial lesions; no biopsy ESGE notes CT enterography can reasonably complement SBCE, particularly when small-bowel tumor is suspected; once diagnostic certainty is high, cross-sectional imaging is recommended for staging and operability assessment (pennazio2023smallbowelcapsuleendoscopy pages 8-9, pennazio2023smallbowelcapsuleendoscopy pages 4-5)
MR enterography / MRI-based small-bowel imaging Alternative or adjunct cross-sectional imaging, especially in surveillance programs and when repeated imaging is anticipated; used with CE in PJS and other hereditary settings Hereditary syndrome surveillance, suspected mass/polyp burden, need to localize lesions or assess bowel beyond mucosa No ionizing radiation; complements CE for localization and burden assessment Less direct mucosal detail than endoscopy; no biopsy or endoscopic therapy Reviews of hereditary SBC surveillance recommend combined approaches using CE with CT/MR enterography; PJS protocols may alternate CE and MRI-enterography every 1-3 years (borsotti2025hereditarycolorectalcancer pages 2-4, borsotti2025hereditarycolorectalcancer pages 19-21, macfarland2024pediatriccancerscreening pages 5-6)
Push enteroscopy / routine upper endoscopy-colonoscopy extensions Targeted use for proximal duodenal/jejunal lesions, especially in FAP/LS where proximal lesions may be reachable by standard upper endoscopy or push techniques Duodenal polyposis, proximal small-bowel lesions, hereditary syndromes with duodenal risk Allows direct inspection/biopsy of reachable proximal lesions; integrates with routine surveillance Limited reach beyond proximal small bowel In FAP, push enteroscopy is recommended for advanced Spigelman stage disease; in LS, duodenal/distal ileal lesions may be accessible with routine gastroscopy/colonoscopy, so routine jejunoileal screening is generally not recommended except selected high-risk groups (borsotti2025hereditarycolorectalcancer pages 12-14)
Multimodal workup pathway Best when suspicion remains despite a single negative test or when hereditary risk is present Persistent obscure bleeding/IDA, positive occult blood with high-risk cancer history, nonresponsive/complicated celiac disease, hereditary syndrome surveillance Improves detection, localization, histologic confirmation, and treatment planning Requires coordination and resource availability Reviews emphasize combining endoscopy, cross-sectional imaging, and genetic risk stratification in tertiary centers; AI-assisted CE/enterography may improve workflow in the future (borsotti2025hereditarycolorectalcancer pages 22-24, borsotti2025hereditarycolorectalcancer pages 1-2, pennazio2023smallbowelcapsuleendoscopy pages 21-21)

Table: This table summarizes the main diagnostic modalities used for suspected small-bowel tumors, including when each test is typically used, its strengths and limitations, and recent guideline-based recommendations. It is useful for comparing first-line luminal evaluation with confirmatory, therapeutic, and staging approaches.

8. Treatment (current applications and real-world implementations)

8.1 Surgery

8.2 Somatostatin analogs (SSAs) and PRRT for SiNET

  • SSAs (octreotide LAR, lanreotide) are described as first-line for SSTR-positive, well-differentiated metastatic gastroenteropancreatic NETs, with low toxicity and tumor growth control (strosberg2024sequencingofsomatostatinreceptor–based pages 4-5).
  • PRRT (e.g., 177Lu-DOTATATE) is a core real-world theranostic modality for progressive midgut NETs and improves progression-free survival in this population, with ongoing work on sequencing vs other systemic therapies (strosberg2024sequencingofsomatostatinreceptor–based pages 1-2).

8.3 Targeted therapy for GIST (approved agents and mutation-informed selection)

The 2023 GEIS guideline states that five TKIs have regulatory approval for metastatic GIST: imatinib, sunitinib, regorafenib, ripretinib, avapritinib (serrano20232023geisguidelines pages 1-3). Molecular-genotype–response relationships include: - KIT exon 11 mutants: 72% objective response with imatinib; exon 9 mutants: 38% response, with higher-dose imatinib benefiting exon 9 disease (serrano20232023geisguidelines pages 10-11). - PDGFRA D842V: resistant to imatinib and most standard therapies (serrano20232023geisguidelines pages 10-11).

These therapies are widely implemented in modern sarcoma/GIST practice and represent one of oncology’s canonical successes of biomarker-driven treatment (serrano20232023geisguidelines pages 1-1).

MAXO (Medical Action Ontology) suggestions (examples)

  • Surgical resection (MAXO:0000001; placeholder—exact MAXO ID not retrieved)
  • Endoscopic biopsy / endoscopic polypectomy
  • Somatostatin analog therapy
  • Peptide receptor radionuclide therapy
  • Tyrosine kinase inhibitor therapy

9. Prevention

9.1 High-risk surveillance as secondary prevention

The most evidence-supported “prevention” approach for SBC in current retrieved sources is surveillance in hereditary syndromes, using CE, enteroscopy, and cross-sectional imaging with gene-informed stratification (borsotti2025hereditarycolorectalcancer pages 1-2, borsotti2025hereditarycolorectalcancer pages 12-14, macfarland2024pediatriccancerscreening pages 5-6).

Table (click to expand)
Syndrome Causal genes / inheritance Small bowel cancer risk estimates Suggested surveillance approach Key citations
Lynch syndrome (LS/HNPCC) Pathogenic variants in MLH1, MSH2, MSH6, PMS2 or EPCAM deletion; autosomal dominant Lifetime small bowel cancer risk reported at 0.4%–12% overall; cumulative incidence by age 75 reported as 64.7% for MLH1, 20.1% for MSH2, 0% for MSH6/PMS2 in the cited review cohort; ~50% of LS-associated small bowel cancers arise in the duodenum (borsotti2025hereditarycolorectalcancer pages 12-14) Routine jejunal/ileal screening is generally not recommended; duodenal/distal ileal lesions may be accessible during routine gastroscopy/colonoscopy; consider more tailored surveillance in MLH1 carriers; capsule endoscopy has low complication rates (0%–0.5%) and reported diagnostic yield up to 8.6% for asymptomatic small-bowel neoplasms (borsotti2025hereditarycolorectalcancer pages 12-14, borsotti2025hereditarycolorectalcancer pages 1-2) (borsotti2025hereditarycolorectalcancer pages 1-2, borsotti2025hereditarycolorectalcancer pages 12-14)
Familial adenomatous polyposis (FAP) APC pathogenic variants; autosomal dominant; de novo cases occur (macfarland2024pediatriccancerscreening pages 4-4) Elevated small bowel/duodenal cancer risk; duodenal surveillance risk stratified by Spigelman classification; jejunal/ileal polyps less well studied (borsotti2025hereditarycolorectalcancer pages 1-2, borsotti2025hereditarycolorectalcancer pages 12-14) Push enteroscopy recommended for Spigelman III–IV disease; double-balloon enteroscopy (DAE) for high polyp burden; surveillance at 3–6 month intervals for high-burden disease or 12-month intervals for minimal disease; multimodal care in tertiary centers emphasized (borsotti2025hereditarycolorectalcancer pages 12-14, borsotti2025hereditarycolorectalcancer pages 1-2) (borsotti2025hereditarycolorectalcancer pages 1-2, borsotti2025hereditarycolorectalcancer pages 12-14, macfarland2024pediatriccancerscreening pages 4-4)
Peutz-Jeghers syndrome (PJS) STK11/LKB1 pathogenic variants; typically autosomal dominant (syndrome context from screening guidance) High small bowel polyp/cancer risk; pediatric complication burden notable, with intussusception >20% by age 10 and >50% by age 20 (macfarland2024pediatriccancerscreening pages 5-6) Start GI screening at age 8 years with endoscopy/colonoscopy plus small bowel imaging (video capsule endoscopy or MR enterography); if polyps are found, repeat every 2–3 years; some protocols alternate CE and MRI-E every 1–3 years; significant polyps ≥15 mm should undergo enteroscopy-assisted resection (borsotti2025hereditarycolorectalcancer pages 19-21, macfarland2024pediatriccancerscreening pages 5-6) (borsotti2025hereditarycolorectalcancer pages 1-2, borsotti2025hereditarycolorectalcancer pages 19-21, macfarland2024pediatriccancerscreening pages 5-6)
Constitutional mismatch repair deficiency (CMMRD) Biallelic mismatch repair gene pathogenic variants; autosomal recessive (borsotti2025hereditarycolorectalcancer pages 19-21) Small bowel cancer prevalence reported at 10%–16%; median diagnosis age around 28 years (borsotti2025hereditarycolorectalcancer pages 19-21) Surveillance includes annual upper endoscopy from age 8 and capsule endoscopy from age 10; concurrent push enteroscopy is recommended because lesions are often duodenal (borsotti2025hereditarycolorectalcancer pages 19-21) (borsotti2025hereditarycolorectalcancer pages 19-21)
MUTYH-associated polyposis (MAP) MUTYH pathogenic variants; usually autosomal recessive (syndrome context reflected in guideline-style review) Duodenal cancer risk described as comparable to FAP; risk focus is mainly proximal small bowel/duodenum (borsotti2025hereditarycolorectalcancer pages 19-21) Surveillance limited to proximal small bowel; upper endoscopy with duodenoscopy starting at age 25–30 years in American guidance or 35 years in European guidance; polypectomy regardless of size is recommended because Spigelman staging is less reliable in MAP (borsotti2025hereditarycolorectalcancer pages 19-21) (borsotti2025hereditarycolorectalcancer pages 19-21)

Table: This table summarizes the major hereditary syndromes linked to small bowel cancer, highlighting causal genes, reported risk estimates, and syndrome-specific surveillance/prevention approaches. It is useful for quickly comparing how surveillance differs across Lynch syndrome, FAP, Peutz-Jeghers syndrome, CMMRD, and MAP.

10. Other Species / Natural Disease

Not retrieved for small intestine cancer specifically in this run (gap).

11. Model Organisms

Not retrieved for small intestine cancer specifically in this run (gap).

12. Recent developments and latest research (emphasis 2023–2024)

Key 2023–2024 developments captured in the retrieved evidence include: 1. Endoscopic technology integration: ESGE guidance formalizes pathways that integrate capsule endoscopy, device-assisted enteroscopy, and cross-sectional imaging for suspected small-bowel tumors, clarifying when DAE should supersede capsule endoscopy when a tumor is already suspected on imaging (pennazio2023smallbowelcapsuleendoscopy pages 8-9). 2. Syndrome-based surveillance modernization: 2024 AACR Childhood Cancer Predisposition Working Group updates support early initiation of small bowel imaging (capsule endoscopy or MR enterography) in pediatric PJS beginning at age 8, reflecting increasing emphasis on life-course surveillance (macfarland2024pediatriccancerscreening pages 5-6). 3. Registry-based epidemiology of rare GI malignancies: 2024–2025 SEER-based analyses provide updated incidence trends and long-horizon survival estimates for small intestine NETs and small intestine GIST, highlighting increasing detection and improving survivorship in some subtypes (dasari2025epidemiologyofneuroendocrine pages 5-7, alvarez2024incidenceandsurvival pages 1-2). 4. Precision therapeutics maturity in rare tumors: 2023 GIST guideline synthesis reiterates that KIT/PDGFRA genotype dictates therapeutic selection and outcome, with multiple approved TKIs and genotype-specific resistance patterns informing sequencing (serrano20232023geisguidelines pages 10-11, serrano20232023geisguidelines pages 1-3).

13. Expert opinion and analysis (authoritative sources)

  • ESGE guideline perspective (2023 Endoscopy): emphasizes that small-bowel tumors are rare and often discovered in workups for bleeding/IDA, and that diagnostic certainty should drive escalation from capsule endoscopy to device-assisted enteroscopy and staging imaging (pennazio2023smallbowelcapsuleendoscopy pages 8-9, pennazio2023smallbowelcapsuleendoscopy pages 21-21).
  • GEIS guideline perspective (2023 Therapeutic Advances in Medical Oncology): positions GIST as a paradigmatic success of molecularly targeted therapy, explicitly noting that KIT/PDGFRA mutations underpin disease initiation/evolution and that multiple TKIs have transformed outcomes (serrano20232023geisguidelines pages 1-1).
  • Nuclear medicine/NET therapy perspective (2024 Journal of Nuclear Medicine): stresses SSTR expression as the biological basis for first-line SSA use and PRRT, while noting that randomized head-to-head sequencing evidence remains limited (strosberg2024sequencingofsomatostatinreceptor–based pages 4-5, strosberg2024sequencingofsomatostatinreceptor–based pages 1-2).

Limitations of this report (evidence gaps)

  1. Ontology identifiers (MONDO, MeSH, Orphanet, ICD) were not obtainable from the retrieved full texts in this tool run.
  2. Small bowel adenocarcinoma (SBA) molecular landscape (somatic driver frequencies, MSI status rates, actionable alterations) was not captured in the accessible evidence.
  3. Environmental/lifestyle risk factors, protective factors, animal models, and disease-specific QoL statistics were not retrieved from the current evidence set.
  4. Image extraction via the available tooling failed for multiple candidate documents; therefore no figure/table image citations are provided.

Summary tables

Table (click to expand)
Entity Definition/notes Approx share or incidence (if in evidence) Typical location Key citations
SBC umbrella Small bowel cancer is a rare malignancy of the small intestine comprising four main histologic groups: adenocarcinomas, neuroendocrine tumors, stromal tumors, and lymphomas. Reviews note adenocarcinoma and neuroendocrine tumor are the two most common categories. Accounts for ~2.3% of digestive cancers; adenocarcinoma and neuroendocrine tumors each represent ~40% of SBC; duodenum is most commonly involved (55–82%), followed by jejunum (11–25%) and ileum (7–17%). Duodenum most common overall; then jejunum and ileum. (borsotti2025hereditarycolorectalcancer pages 1-2)
SBA Small bowel adenocarcinoma is the epithelial adenocarcinoma subtype of SBC; prognosis is often limited by late diagnosis and management complexity. In hereditary settings, it can arise through an adenoma-carcinoma sequence, especially in Lynch syndrome. Included within the ~40% adenocarcinoma share of SBC; SEER-based prognostic study analyzed 2,064 SBA cases diagnosed 2010–2020. Often duodenal overall; in Lynch syndrome, nearly 50% of small bowel cancers occur in the duodenum. (borsotti2025hereditarycolorectalcancer pages 1-2, borsotti2025hereditarycolorectalcancer pages 12-14)
SiNET Small intestinal neuroendocrine tumor (midgut/small-bowel NET) is a well-differentiated neuroendocrine neoplasm of the small intestine; commonly SSTR-positive and often slow-growing but prone to mesenteric nodal/liver spread. Small intestine NET incidence ~1.2–1.41 per 100,000 persons in recent US SEER analyses; small bowel NETs are among the most common GEP-NET sites; 10-year overall survival reported at 51.7% in one SEER-based analysis. Frequently ileal/midgut; ileal/ileocecal primaries are emphasized in treatment reviews. (dasari2025epidemiologyofneuroendocrine pages 5-7, dasari2025epidemiologyofneuroendocrine pages 1-2, dasari2025epidemiologyofneuroendocrine pages 4-5, strosberg2024sequencingofsomatostatinreceptor–based pages 1-2)
Small intestine GIST Gastrointestinal stromal tumor is the principal mesenchymal/stromal tumor category of the small intestine, usually driven by KIT or PDGFRA alterations and characterized by KIT (CD117) expression in >95% of cases. Small intestine is the primary site in ~31% of GISTs; global GIST incidence ~10–15 per million people; small intestine GIST incidence increased by 2.7% annually in SEER 2000–2019. Small intestine is a major primary site after stomach; may present as multifocal disease in NF1-associated cases. (serrano20232023geisguidelines pages 1-3, alvarez2024incidenceandsurvival pages 1-2, wang2026targetedtherapyfor pages 1-2)

Table: This table summarizes the disease scope of small intestine cancer, highlighting the umbrella category and the major clinically important histologic subtypes. It is useful for orienting a knowledge base entry to the main entities, their approximate frequencies or incidence, and their usual anatomic distribution.

References

  1. (borsotti2025hereditarycolorectalcancer pages 1-2): Edoardo Borsotti, Francesca Laura Nava, Felice Benedicenti, Laura Cini, Andrea Magarotto, Davide Ferrari, Paolo Cantù, Marco Vitellaro, Emanuele Rausa, and Federica Cavalcoli. Hereditary colorectal cancer syndromes: small bowel cancer risk and endoscopic surveillance strategies. Diagnostics, 15:819, Mar 2025. URL: https://doi.org/10.3390/diagnostics15070819, doi:10.3390/diagnostics15070819. This article has 5 citations.

  2. (borsotti2025hereditarycolorectalcancer pages 12-14): Edoardo Borsotti, Francesca Laura Nava, Felice Benedicenti, Laura Cini, Andrea Magarotto, Davide Ferrari, Paolo Cantù, Marco Vitellaro, Emanuele Rausa, and Federica Cavalcoli. Hereditary colorectal cancer syndromes: small bowel cancer risk and endoscopic surveillance strategies. Diagnostics, 15:819, Mar 2025. URL: https://doi.org/10.3390/diagnostics15070819, doi:10.3390/diagnostics15070819. This article has 5 citations.

  3. (pennazio2023smallbowelcapsuleendoscopy pages 8-9): Marco Pennazio, Emanuele Rondonotti, Edward J. Despott, Xavier Dray, Martin Keuchel, Tom Moreels, David S. Sanders, Cristiano Spada, Cristina Carretero, Pablo Cortegoso Valdivia, Luca Elli, Lorenzo Fuccio, Begona Gonzalez Suarez, Anastasios Koulaouzidis, Lumir Kunovsky, Deirdre McNamara, Helmut Neumann, Enrique Perez-Cuadrado-Martinez, Enrique Perez-Cuadrado-Robles, Stefania Piccirelli, Bruno Rosa, Jean-Christophe Saurin, Reena Sidhu, Ilja Tacheci, Erasmia Vlachou, and Konstantinos Triantafyllou. Small-bowel capsule endoscopy and device-assisted enteroscopy for diagnosis and treatment of small-bowel disorders: european society of gastrointestinal endoscopy (esge) guideline – update 2022. Endoscopy, 55:58-95, Nov 2023. URL: https://doi.org/10.1055/a-1973-3796, doi:10.1055/a-1973-3796. This article has 391 citations and is from a domain leading peer-reviewed journal.

  4. (pennazio2023smallbowelcapsuleendoscopy pages 21-21): Marco Pennazio, Emanuele Rondonotti, Edward J. Despott, Xavier Dray, Martin Keuchel, Tom Moreels, David S. Sanders, Cristiano Spada, Cristina Carretero, Pablo Cortegoso Valdivia, Luca Elli, Lorenzo Fuccio, Begona Gonzalez Suarez, Anastasios Koulaouzidis, Lumir Kunovsky, Deirdre McNamara, Helmut Neumann, Enrique Perez-Cuadrado-Martinez, Enrique Perez-Cuadrado-Robles, Stefania Piccirelli, Bruno Rosa, Jean-Christophe Saurin, Reena Sidhu, Ilja Tacheci, Erasmia Vlachou, and Konstantinos Triantafyllou. Small-bowel capsule endoscopy and device-assisted enteroscopy for diagnosis and treatment of small-bowel disorders: european society of gastrointestinal endoscopy (esge) guideline – update 2022. Endoscopy, 55:58-95, Nov 2023. URL: https://doi.org/10.1055/a-1973-3796, doi:10.1055/a-1973-3796. This article has 391 citations and is from a domain leading peer-reviewed journal.

  5. (strosberg2024sequencingofsomatostatinreceptor–based pages 1-2): Jonathan R. Strosberg, Taymeyah Al-Toubah, Ghassan El-Haddad, Diane Reidy Lagunes, and Lisa Bodei. Sequencing of somatostatin-receptor–based therapies in neuroendocrine tumor patients. The Journal of Nuclear Medicine, 65:340-348, Jan 2024. URL: https://doi.org/10.2967/jnumed.123.265706, doi:10.2967/jnumed.123.265706. This article has 27 citations.

  6. (serrano20232023geisguidelines pages 1-3): César Serrano, Javier Martín-Broto, José Manuel Asencio-Pascual, José Antonio López-Guerrero, Jordi Rubió-Casadevall, Silvia Bagué, Xavier García-del-Muro, Juan Ángel Fernández-Hernández, Luís Herrero, Antonio López-Pousa, Andrés Poveda, and Virginia Martínez-Marín. 2023 geis guidelines for gastrointestinal stromal tumors. Therapeutic Advances in Medical Oncology, Jan 2023. URL: https://doi.org/10.1177/17588359231192388, doi:10.1177/17588359231192388. This article has 156 citations and is from a peer-reviewed journal.

  7. (dasari2025epidemiologyofneuroendocrine pages 5-7): Arvind Dasari, Katrine Wallace, Daniel M. Halperin, Jessica Maxwell, Pamela Kunz, Simron Singh, Beth Chasen, and James C. Yao. Epidemiology of neuroendocrine neoplasms in the us. JAMA Network Open, 8:e2515798, Jun 2025. URL: https://doi.org/10.1001/jamanetworkopen.2025.15798, doi:10.1001/jamanetworkopen.2025.15798. This article has 98 citations and is from a peer-reviewed journal.

  8. (alvarez2024incidenceandsurvival pages 1-2): Christian S. Alvarez, M. Blanca Piazuelo, Tania Fleitas-Kanonnikoff, Jennifer Ruhl, J. Alejandro Pérez-Fidalgo, and M. Constanza Camargo. Incidence and survival outcomes of gastrointestinal stromal tumors. Aug 2024. URL: https://doi.org/10.1001/jamanetworkopen.2024.28828, doi:10.1001/jamanetworkopen.2024.28828. This article has 54 citations and is from a peer-reviewed journal.

  9. (macfarland2024pediatriccancerscreening pages 5-6): Suzanne P. MacFarland, Kerri Becktell, Kami Wolfe Schneider, Roland P. Kuiper, Harry Lesmana, Julia Meade, Kim E. Nichols, Christopher C. Porter, Sharon A. Savage, Kris Ann Schultz, Hamish Scott, Lisa States, Uri Tabori, Chieko Tamura, Gail Tomlinson, Kristin Zelley, Carol Durno, Andrew Bauer, and Sharon E. Plon. Pediatric cancer screening in hereditary gastrointestinal cancer risk syndromes: an update from the aacr childhood cancer predisposition working group. Clinical cancer research : an official journal of the American Association for Cancer Research, 30:4566-4571, Aug 2024. URL: https://doi.org/10.1158/1078-0432.ccr-24-0953, doi:10.1158/1078-0432.ccr-24-0953. This article has 25 citations.

  10. (serrano20232023geisguidelines pages 1-1): César Serrano, Javier Martín-Broto, José Manuel Asencio-Pascual, José Antonio López-Guerrero, Jordi Rubió-Casadevall, Silvia Bagué, Xavier García-del-Muro, Juan Ángel Fernández-Hernández, Luís Herrero, Antonio López-Pousa, Andrés Poveda, and Virginia Martínez-Marín. 2023 geis guidelines for gastrointestinal stromal tumors. Therapeutic Advances in Medical Oncology, Jan 2023. URL: https://doi.org/10.1177/17588359231192388, doi:10.1177/17588359231192388. This article has 156 citations and is from a peer-reviewed journal.

  11. (macfarland2024pediatriccancerscreening pages 4-4): Suzanne P. MacFarland, Kerri Becktell, Kami Wolfe Schneider, Roland P. Kuiper, Harry Lesmana, Julia Meade, Kim E. Nichols, Christopher C. Porter, Sharon A. Savage, Kris Ann Schultz, Hamish Scott, Lisa States, Uri Tabori, Chieko Tamura, Gail Tomlinson, Kristin Zelley, Carol Durno, Andrew Bauer, and Sharon E. Plon. Pediatric cancer screening in hereditary gastrointestinal cancer risk syndromes: an update from the aacr childhood cancer predisposition working group. Clinical cancer research : an official journal of the American Association for Cancer Research, 30:4566-4571, Aug 2024. URL: https://doi.org/10.1158/1078-0432.ccr-24-0953, doi:10.1158/1078-0432.ccr-24-0953. This article has 25 citations.

  12. (borsotti2025hereditarycolorectalcancer pages 19-21): Edoardo Borsotti, Francesca Laura Nava, Felice Benedicenti, Laura Cini, Andrea Magarotto, Davide Ferrari, Paolo Cantù, Marco Vitellaro, Emanuele Rausa, and Federica Cavalcoli. Hereditary colorectal cancer syndromes: small bowel cancer risk and endoscopic surveillance strategies. Diagnostics, 15:819, Mar 2025. URL: https://doi.org/10.3390/diagnostics15070819, doi:10.3390/diagnostics15070819. This article has 5 citations.

  13. (tan2024gastroenteropancreaticneuroendocrineneoplasms pages 8-9): Baizhou Tan, Beiyu Zhang, and Hongping Chen. Gastroenteropancreatic neuroendocrine neoplasms: epidemiology, genetics, and treatment. Frontiers in Endocrinology, Sep 2024. URL: https://doi.org/10.3389/fendo.2024.1424839, doi:10.3389/fendo.2024.1424839. This article has 32 citations.

  14. (dasari2025epidemiologyofneuroendocrine pages 4-5): Arvind Dasari, Katrine Wallace, Daniel M. Halperin, Jessica Maxwell, Pamela Kunz, Simron Singh, Beth Chasen, and James C. Yao. Epidemiology of neuroendocrine neoplasms in the us. JAMA Network Open, 8:e2515798, Jun 2025. URL: https://doi.org/10.1001/jamanetworkopen.2025.15798, doi:10.1001/jamanetworkopen.2025.15798. This article has 98 citations and is from a peer-reviewed journal.

  15. (dasari2025epidemiologyofneuroendocrine pages 1-2): Arvind Dasari, Katrine Wallace, Daniel M. Halperin, Jessica Maxwell, Pamela Kunz, Simron Singh, Beth Chasen, and James C. Yao. Epidemiology of neuroendocrine neoplasms in the us. JAMA Network Open, 8:e2515798, Jun 2025. URL: https://doi.org/10.1001/jamanetworkopen.2025.15798, doi:10.1001/jamanetworkopen.2025.15798. This article has 98 citations and is from a peer-reviewed journal.

  16. (borsotti2025hereditarycolorectalcancer pages 2-4): Edoardo Borsotti, Francesca Laura Nava, Felice Benedicenti, Laura Cini, Andrea Magarotto, Davide Ferrari, Paolo Cantù, Marco Vitellaro, Emanuele Rausa, and Federica Cavalcoli. Hereditary colorectal cancer syndromes: small bowel cancer risk and endoscopic surveillance strategies. Diagnostics, 15:819, Mar 2025. URL: https://doi.org/10.3390/diagnostics15070819, doi:10.3390/diagnostics15070819. This article has 5 citations.

  17. (pennazio2023smallbowelcapsuleendoscopy pages 4-5): Marco Pennazio, Emanuele Rondonotti, Edward J. Despott, Xavier Dray, Martin Keuchel, Tom Moreels, David S. Sanders, Cristiano Spada, Cristina Carretero, Pablo Cortegoso Valdivia, Luca Elli, Lorenzo Fuccio, Begona Gonzalez Suarez, Anastasios Koulaouzidis, Lumir Kunovsky, Deirdre McNamara, Helmut Neumann, Enrique Perez-Cuadrado-Martinez, Enrique Perez-Cuadrado-Robles, Stefania Piccirelli, Bruno Rosa, Jean-Christophe Saurin, Reena Sidhu, Ilja Tacheci, Erasmia Vlachou, and Konstantinos Triantafyllou. Small-bowel capsule endoscopy and device-assisted enteroscopy for diagnosis and treatment of small-bowel disorders: european society of gastrointestinal endoscopy (esge) guideline – update 2022. Endoscopy, 55:58-95, Nov 2023. URL: https://doi.org/10.1055/a-1973-3796, doi:10.1055/a-1973-3796. This article has 391 citations and is from a domain leading peer-reviewed journal.

  18. (borsotti2025hereditarycolorectalcancer pages 4-5): Edoardo Borsotti, Francesca Laura Nava, Felice Benedicenti, Laura Cini, Andrea Magarotto, Davide Ferrari, Paolo Cantù, Marco Vitellaro, Emanuele Rausa, and Federica Cavalcoli. Hereditary colorectal cancer syndromes: small bowel cancer risk and endoscopic surveillance strategies. Diagnostics, 15:819, Mar 2025. URL: https://doi.org/10.3390/diagnostics15070819, doi:10.3390/diagnostics15070819. This article has 5 citations.

  19. (borsotti2025hereditarycolorectalcancer pages 22-24): Edoardo Borsotti, Francesca Laura Nava, Felice Benedicenti, Laura Cini, Andrea Magarotto, Davide Ferrari, Paolo Cantù, Marco Vitellaro, Emanuele Rausa, and Federica Cavalcoli. Hereditary colorectal cancer syndromes: small bowel cancer risk and endoscopic surveillance strategies. Diagnostics, 15:819, Mar 2025. URL: https://doi.org/10.3390/diagnostics15070819, doi:10.3390/diagnostics15070819. This article has 5 citations.

  20. (strosberg2024sequencingofsomatostatinreceptor–based pages 4-5): Jonathan R. Strosberg, Taymeyah Al-Toubah, Ghassan El-Haddad, Diane Reidy Lagunes, and Lisa Bodei. Sequencing of somatostatin-receptor–based therapies in neuroendocrine tumor patients. The Journal of Nuclear Medicine, 65:340-348, Jan 2024. URL: https://doi.org/10.2967/jnumed.123.265706, doi:10.2967/jnumed.123.265706. This article has 27 citations.

  21. (serrano20232023geisguidelines pages 10-11): César Serrano, Javier Martín-Broto, José Manuel Asencio-Pascual, José Antonio López-Guerrero, Jordi Rubió-Casadevall, Silvia Bagué, Xavier García-del-Muro, Juan Ángel Fernández-Hernández, Luís Herrero, Antonio López-Pousa, Andrés Poveda, and Virginia Martínez-Marín. 2023 geis guidelines for gastrointestinal stromal tumors. Therapeutic Advances in Medical Oncology, Jan 2023. URL: https://doi.org/10.1177/17588359231192388, doi:10.1177/17588359231192388. This article has 156 citations and is from a peer-reviewed journal.

  22. (wang2026targetedtherapyfor pages 1-2): Xiao-Dong Wang, Chun-Hui Shou, Sheng-Chuan Chen, Yan-Yun Hong, Kan-Kai Zhu, Wei-Li Yang, and Ji-Ren Yu. Targeted therapy for advanced gastrointestinal stromal tumors: evolution and future directions. Drug Design, Development and Therapy, Volume 20:1-23, Mar 2026. URL: https://doi.org/10.2147/dddt.s594043, doi:10.2147/dddt.s594043. This article has 1 citations.

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