Table 1. Baseline demographics and GIST characteristics.
| Variable | Total, N=38 |
|---|---|
| Median age, years | 60.0 (32–77) |
| Male, n (%) | 22 (57.9) |
| Race, n (%) | |
| Caucasian | 29 (76.3) |
| Other | 9 (23.7) |
| ECOG performance status, n (%) | |
| 0 | 23 (60.5) |
| 1 | 15 (39.5) |
| Primary site of cancer, n (%) | |
| Oesophagus | 1 (2.6) |
| Stomach | 15 (39.5) |
| Small intestine | 15 (39.5) |
| Rectum | 2 (5.3) |
| Other | 5 (13.2) |
| Tumour histology, n (%) | |
| Epithelioid | 5 (13.2) |
| Spindle | 17 (44.7) |
| Mixed | 11 (28.9) |
| Other | 5 (13.2) |
| Mitotic count per 50 HPFs, n (%) | |
| ⩽5/50 | 8 (21.1) |
| >5/50 to ⩽10/50 | 6 (15.8) |
| >10/50 | 10 (26.3) |
| Not evaluablea | 9 (23.7) |
| Missing | 5 (13.2) |
| Metastatic site, n (%)b | |
| Pleural effusion (malignant) | 1 (2.6) |
| Lung | 1 (2.6) |
| Thoracic lymph nodes | 2 (5.3) |
| Spleen | 1 (2.6) |
| Liver | 26 (68.4) |
| Stomach | 1 (2.6) |
| Peritoneum | 17 (44.7) |
| Adrenal | 1 (2.6) |
| Bladder | 2 (5.3) |
| Bone, lumbar vertebrae | 1 (2.6) |
| Other | 6 (15.8) |
| Median number of target lesions (range) | 2 (1–5) |
| Median longest diameter of the largest target lesion, cm (range) | 7.0 (1.3–25.0) |
| Disease progression while on imatinib, n (%) | 33 (86.8) |
| Median time on imatinib, days (range) | 132 (19–2065) |
| Intolerant to imatinib, n (%)c | 8 (21.1) |
| Gene mutation | |
| KIT mutation | |
| Exon 9 | 5 (13.2) |
| Exon 11 | 14 (36.8) |
| Exon 17 | 1 (2.6) |
| Exons 11 and 17 | 1 (2.6) |
| PDGFRA mutation | |
| Exon 12 | 1 (2.6) |
| Exon 18 | 1 (2.6) |
| Exon D842V | 2 (5.3) |
| Not available | 13 (34.2) |
Abbreviations: ECOG=Eastern Cooperative Oncology Group; HPF=high power fields.
a
Patients for whom the mitotic index was not recorded as fraction of 50 HPFs.
b
One patient may have more than one metastatic site.
c
Three patients reported as both progressed on imatinib and intolerant to imatinib.