Table 1.
Clinicopathologic characteristics of 57 specimens from 50 patients
| Characteristic | Untreated | Sensitive | Resistant |
| Number of patients | 25 | 18 | 9a |
| Number of specimens | 25 | 23 | 9 |
| Median age (range) | 65 (38-85) | 58 (43-81) | 53 (39-66) |
| Female | 13 | 4 | 3 |
| Male | 12 | 14 | 6 |
| Primary | 25 | 9 | 2 |
| Metastatic | 0 | 14 | 6 |
| Local recurrence | 0 | 0 | 1 |
| Primary location | |||
| Stomach | 23 | 7 | 4 |
| Small intestine | 1 | 12 | 4 |
| Other | 1 | 4 | 1 |
| Tyrosine kinase inhibitor | |||
| Imatinib | Not applicable | 23 | 9 |
| Sunitinib | Not applicable | 0 | 5 |
| Other | Not applicable | 0 | 2 |
| Median treatment duration (months) | Not applicable | 6 (3-84) | 84 (36-132)b |
| Mutational status | |||
| KIT exon 9 | 0 | 2 | 1 |
| KIT exon 11 | 6 | 9c | 8d |
| KIT exon 13 | 0 | 1 | 0 |
| PDGFRA | 2 | 0 | 0 |
| WT | 2 | 0 | 0 |
| Unavailable | 15 | 6 | 0 |
a
Two patients also had sensitive tumors.
b
Shows duration of any treatment.
c
One patient had a secondary KIT exon 17 mutation but was still sensitive by clinical criteria.
d
Two patients had secondary KIT exon 13 mutations and 1 had a secondary KIT exon 17 mutation.