Table 1.
Molecular classification of GIST.
| Gene | Incidence | Anatomic location | Imatinib sensitivity |
|---|---|---|---|
| Mutations in KIT (80%) | |||
| Exon 9 | 7% | Small intestine, colon | Yes, consider 800mg/day |
| Exon 11 | 65% | All locations | Yes |
| Exon 13 | 1% | All locations | Variable |
| Exon 17 | 1% | All locations | Variable |
| Mutations in PDGFRA (5–8%) | |||
| Exon 12 | 2% | All locations | Yes |
| Exon 14 | <1% | Stomach | Yes |
| Exon 18 | 7% | Stomach, mesentary, omentum | D842V insensitive, most other sensitive |
| WT (12–15%) | |||
| BRAF V600E | 7–15%* | Stomach, small intestine | Possibly |
| SDHA, SDHB, SDHC, SDHD | 12%* | Stomach, small intestine | Usually not |
| Familiar GIST | |||
| KIT, rarely PDGFRA | Very rare | Small intestine | Usually not |
| Syndromic GIST | |||
| Unknown gene (Carney Triad) | Very rare | Stomach | Usually not |
| SDHB, SDHC, SDHD (Carney-Stratakis) | Rare | Stomach | Usually not |
| NF1 (Neurofibromatosis-1) | Rare | Small intestine | Usually not |
*
indicates % of WT GISTs.
Data from Joensuu H, DeMatteo RP. The management of gastrointestinal stromal tumors: a model for targeted and multidisciplinary therapy of malignancy. Annu Rev Med. 2012;63:247–258.