TABLE I.
Prognostication of GIST of Different Sites by Tumor Size and Mitotic Rate Based on Follow-Up Studies of Over >1,700 GISTs 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 | ≤5/50 HPFs | 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 higha | 57 higha | |
| 3b | >10 cm | 12 moderate | 52 high | |||
| 4 | ≤2 cm | >5/50 HPFs | 0a | 50a | b | 54 high |
| 5 | >2 ≤ 5 cm | 16 moderate | 73 high | 50 high | 52 high | |
| 6a | >5 ≤ 10 cm | 55 high | 85 high | 86 higha | 71 higha | |
| 6b | >10 cm | 86 high | 90 high | |||
Table adopted from Miettinen and Lasota. Arch Pathol Lab Med 2006;130:1466–1478.
HPF, high power field. 50 high power fields equal here approximately 5 mm2.
a
Small number of cases. Groups combined or prognostic prediction less certain.
b
No tumors encountered with these parameters.