Endoscopic treatment for gastrointestinal stromal tumor: Advantages and hurdles

Table 1 Prognostication of gastrointestinal stromal tumor atdifferent sites by tumor size and mitotic rate based on follow-up studies of over 1700 gastrointestinal stromal tumors prior to imatinib

Tumor parameters			Percentage of patients with progressive disease during long-term follow-up and quantitative characterization of the risk for metastasis
Group	Size	Mitotic rate	Gastric GISTs	Small intestinal GISTs	Duodenal GISTs	Rectal GISTs
1	≤ 2 cm	≤ 5/50HPFs	0 none
2	> 2 ≤ 5 cm		1.9 (very low)	4.3 (low)	8.3 (low)	8.5 (low)
3a	> 5 ≤ 10 cm		3.6 (low)	24 (moderate)	34 (high) 1	57 (high) 1
3b	> 10 cm		12 (moderate)	52 (high)
4	≤ 2 cm	> 5/50HPFs	01	501	2	54 (high)
5	> 2 ≤ 5 cm		16 (moderate)	73 (high)	50 (high)	52 (high)
6a	> 5 ≤ 10 cm		55 (high)	85 (high)	86 (high) 1	71 (high) 1
6b	> 10 cm		86 (high)	90 (high)

¹Small number of cases. Groups combined or prognostic prediction less certain;

²No tumors encountered with these parameters. (Adopted from Miettinen et al[4]). HPF: High power field; 50 high: Power fields equal approximately 5 mm²; GIST: Gastrointestinal stromal tumor.