Current research and treatment for gastrointestinal stromal tumors

Table 1 National Institutes of Health vs Armed Forces Institute of Pathology criteria for assessing malignant risk of gastrointestinal stromal tumors

Degree of risk	NIH criteria	AFIP criteria
Unknown	-	< 2 cm and ≤ 5 mitotic index
Very low	< 2 cm and < 5 mitotic index	≤ 5 cm and ≤ 5 mitotic index
Low	2-5 cm and < 5 mitotic index	Gastric: > 5 cm and ≤ 5 mitotic index
		Others: 2-5 cm and ≤ 5 mitotic index
Intermediate or moderate	5-10 cm and < 5 mitotic index	Gastric: > 10 cm and ≤ 5 mitotic index or > 2-5 cm and > 5 mitotic index
	> 5 cm and 6-10 mitotic index	Others: 5-10 cm and ≤ 5 mitotic index
High	> 5 cm and > 5 mitotic index	Gastric: > 5 cm and > 5 mitotic index
	> 10 cm and any mitotic index	Others: > 10 cm and > 5 mitotic index
	Any size and > 10 mitotic index

Mitotic index = number of mitoses per 50 high-power field. AFIP: Armed Forces Institute of Pathology; NIH: National Institutes of Health.