Small Intestine Cancer Symptoms, Screening and Diagnosis
Staging
Small intestine cancers are typically given a clinical stage based on the results of any exams, biopsies, and imaging tests that might have been done. If surgery has been done, the pathologic stage (also called the surgical stage) can also be determined.
Small intestine cancers typically start in the inner lining of the intestine. As they grow, they can spread into deeper layers. These layers include:
- Mucosa: This is the innermost layer. It has 3 parts: the top layer of cells (called the epithelium), a thin layer of connective tissue (called the lamina propria), and a thin layer of muscle (called the muscularis mucosa).
- Submucosa: This is the fibrous tissue that lies beneath the mucosa.
- Thick muscle layers (muscularis propria): This layer of muscle contracts to force the food along the GI tract.
- Subserosa and serosa: These are the thin outermost layers of connective tissue that cover the GI tract. The serosa is also known as the visceral peritoneum.
The staging system most often used for small intestine cancer is the American Joint Committee on Cancer (AJCC) TNM system
| T staging | |
| TX | Primary tumour could not be evaluated |
| T0 | No evidence of primary tumour |
| Tis | High-grade squamous intraepithelial lesion, carcinoma in-situ |
| T1 | Tumour < 2 cm |
| T2 | Tumour 2-5 cm |
| T3 | Tumour > 5 cm |
| T4 | Tumour of any size with adjacent organ invasion |
| N staging | |
| NX | Regional lymph node could not be evaluated |
| N0 | No metastatic lymph nodes |
| N1 | Inguinal, Mesorectal, Internal iliac, or external iliac nodes |
| N1a | Inguinal, Mesorectal, or Internal iliac lymph nodes |
| N1b | External iliac lymph nodes |
| N1c | External iliac lymph nodes with N1a |
| M staging | |
| M0 | No distant metastasis |
| M1 | Distant metastasis |
Literature
1. Greene, F. L., & Sobin, L. H. (2008). The staging of cancer: A retrospective and prospective appraisal. CA: A Cancer Journal for Clinicians, 58(3), 180–190. https://doi.org/10.3322/CA.2008.0001