# GIST risk stratification (mitotic count, size, site; Miettinen and modified NIH criteria)

Source: https://onco.cc/terms/gist-risk-stratification/  
OnCo record `gist-risk-stratification` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Whether a gastrointestinal stromal tumour will come back after surgery is read from three things on the pathology report, its size, how many cells are dividing in a 5 square millimetre field, and where it started (stomach is safer than small bowel or rectum), plus whether it ruptured; high-risk patients get three years of imatinib and the others get none.

## Summary

What is measured: the probability that a resected GIST will recur. How: tumour size in centimetres, mitotic count per 5 mm² (about 50 high-power fields; 5 or fewer against more than 5), the site of origin and rupture before or during surgery, read against the Miettinen and Lasota (AFIP, 2006) tables (a gastric tumour of 5 cm or less with 5 or fewer mitoses has a 0 to 2 percent risk; a small-bowel tumour over 10 cm or with more than 5 mitoses a 50 to 90 percent risk), the modified NIH criteria (Joensuu 2008) that add rupture as high risk, and nomograms and contour maps. The genotype is read alongside: KIT exon 11 deletions involving codons 557 and 558 are worse, PDGFRA D842V tumours are indolent and imatinib-insensitive, SDH-deficient tumours follow their own course; KIT (CD117) and DOG1 immunohistochemistry make the diagnosis. What a result changes: high risk or rupture means three years of adjuvant imatinib (SSG XVIII: five-year survival 92 against 82 percent with one year; five years against three is being tested), with the dose and the decision informed by genotype (no adjuvant imatinib for D842V); intermediate risk is discussed case by case; low and very low risk get follow-up only, with imaging intensity set by risk. Where it matters: GIST and its KIT exon 11, PDGFRA D842V and imatinib-resistant pages.

## Fields

- Kind: Term
- Last checked: 2026-09-17
- Also known as: Miettinen criteria; Miettinen risk; AFIP criteria; modified NIH criteria; Fletcher criteria; Joensuu criteria; GIST risk; GIST risk classification; mitotic count per 5 mm²; mitotic index in GIST; high-risk GIST; intermediate-risk GIST; low-risk GIST; very low risk GIST; tumour rupture in GIST

## Connected records

- targets: [KIT](https://onco.cc/targets/kit/), [PDGFRA](https://onco.cc/targets/pdgfra/)
- drugs: [Avapritinib](https://onco.cc/drugs/avapritinib/), [Imatinib](https://onco.cc/drugs/imatinib/)
- terms: [Grade](https://onco.cc/terms/tumour-grade/), [Immunohistochemistry (IHC)](https://onco.cc/terms/ihc/), [Resection margins (R0 / R1 / R2)](https://onco.cc/terms/resection-margins/), [SDH deficiency (SDHB immunohistochemistry loss)](https://onco.cc/terms/sdh-deficiency/)
- cancers: [Gastrointestinal stromal tumour (GIST)](https://onco.cc/cancers/gist/), [Imatinib-resistant GIST](https://onco.cc/cancers/gist-imatinib-resistant/), [KIT exon 11-mutant GIST](https://onco.cc/cancers/gist-kit-exon-11/), [PDGFRA D842V-mutant GIST](https://onco.cc/cancers/gist-pdgfra-d842v/)

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