Primary tumor (pT)
- TX: Primary tumor cannot be assessed
- T0: No evidence of primary tumor
- T1: Tumor ≤ 2 cm
- T2: Tumor > 2 cm but ≤ 5 cm
- T3: Tumor > 5 cm but ≤ 10 cm
- T4: Tumor > 10 cm
Stomach
General
Staging-GIST
Author: Raul S. Gonzalez, M.D.
Editor-in-Chief: Debra L. Zynger, M.D.
Last author update: 10 December 2020
Last staff update: 11 June 2021
Copyright: 2003-2023, PathologyOutlines.com, Inc.
PubMed Search: Staging gastrointestinal stromal tumor [title]
Table of Contents
Definition / general | Essential features | ICD coding | Primary tumor (pT) | Regional lymph nodes (pN) | Distant metastasis (pM) | Mitotic rate | Prefixes | Stage grouping | Registry data collection variables | Histologic grade | Histopathologic type | Survival data | Board review style question #1 | Board review style answer #1Cite this page: Gonzalez RS. Staging-GIST. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/stomachgiststaging.html. Accessed June 8th, 2023.
Pathologic TNM staging of gastrointestinal stromal tumors, AJCC 8th edition
Definition / general
- Sporadic nonpediatric gastrointestinal stromal tumors (GISTs) of any gastrointestinal organ are covered by this staging system
- Pediatric, familial and syndromic GISTs are not staged using AJCC criteria
Essential features
- AJCC 7th edition staging was sunset on December 31, 2017; as of January 1, 2018, use of the 8th edition is mandatory (Amin: AJCC Cancer Staging Manual, 8th Edition, 2018)
ICD coding
- C49.A0: Gastrointestinal stromal tumor, unspecified site
Regional lymph nodes (pN)
- N0: No regional lymph node metastasis or unknown lymph node status
- N1: Regional lymph node metastasis
Notes:
- Nodal metastasis is very rare in sporadic nonpediatric GISTs
- Regional lymph nodes vary depending on site of origin
Distant metastasis (pM)
- M0: No distant metastasis
- M1: Distant metastasis
Prefixes
- y: Preoperative radiotherapy or chemotherapy
- r: Recurrent tumor stage
Stage grouping
Gastric and omental GIST
Esophageal, small intestinal, colorectal, mesenteric and peritoneal GIST
| Stage IA: | T1 - 2 | N0 | M0 | Low mitotic rate |
| Stage IB: | T3 | N0 | M0 | Low mitotic rate |
| Stage II: | T1 - 2 | N0 | M0 | High mitotic rate |
| T4 | N0 | M0 | Low mitotic rate | |
| Stage IIIA: | T3 | N0 | M0 | High mitotic rate |
| Stage IIIB: | T4 | N0 | M0 | High mitotic rate |
| Stage IVA: | Any T | N1 | M0 | Any mitotic rate |
| Any T | Any N | M1 | Any mitotic rate |
Esophageal, small intestinal, colorectal, mesenteric and peritoneal GIST
| Stage I: | T1 - 2 | N0 | M0 | Low mitotic rate |
| Stage II: | T3 | N0 | M0 | Low mitotic rate |
| Stage IIIA: | T4 | N0 | M0 | Low mitotic rate |
| T1 | N0 | M0 | High mitotic rate | |
| Stage IIIB: | T2 - 4 | N0 | M0 | High mitotic rate |
| Stage IVA: | Any T | N1 | M0 | Any mitotic rate |
| Any T | Any N | M1 | Any mitotic rate |
Registry data collection variables
- Tumor size
- Tumor site (esophagus, stomach, duodenum, jejunum / ileum, rectum, extraintestinal)
- Tumor mitotic rate
- Tumor rupture
- Tumor metastasis (liver, peritoneum, other)
- Tumor KIT immunohistochemistry
- Tumor mutational status of KIT and PDGFRA (if known)
Histologic grade
- Same as mitotic rate (see above)
Histopathologic type
- Spindle cell, epithelioid and mixed cell types
Survival data
Gastric GISTs
Small intestinal GISTs
| Stage | Tumor size (cm) | Mitotic rate | Observed rate of progressive disease |
| Stage IA: | ≤ 5 | Low | 0 - 2% |
| Stage IB: | > 5 - 10 | Low | 3 - 4% |
| Stage II: | ≤ 2 | High | Insufficient data |
| > 2 - 5 | High | 16% | |
| > 10 | Low | 12% | |
| Stage IIIA: | > 5 - 10 | High | 55% |
| Stage IIIB: | > 10 | High | 86% |
Small intestinal GISTs
| Stage | Tumor size (cm) | Mitotic rate | Observed rate of progressive disease |
| Stage IA: | ≤ 5 | Low | 0 - 4% |
| Stage II: | > 5 - 10 | Low | 24% |
| Stage IIIA: | ≥ 10 | Low | 52% |
| ≤ 2 | High | 50% | |
| Stage IIIB: | > 2 - 5 | High | 73% |
| > 5 - 10 | High | 85% | |
| > 10 | High | 90% |
Board review style question #1
Using AJCC 8th edition criteria, which of the following neoplasms may be staged as pN0 even if no lymph nodes are received for pathologic examination?
- Appendiceal goblet cell carcinoid
- Gastric neuroendocrine carcinoma
- Gastrointestinal stromal tumor
- Rectal adenocarcinoma with neoadjuvant treatment
Board review style answer #1
