TABLE 1.
Characteristics of Patients and Tumors in the SSGXVIII/AIO Series
| Factor | Enrolled to 12 mo of Imatinib (n = 181) No. (%)a |
Enrolled to 36 mo of Imatinib (n = 177) No. (%) |
|---|---|---|
| Sex | ||
| Women | 85 (47) | 89 (50) |
| Men | 96 (53) | 88 (50) |
| Age, y | ||
| ≤61 (median) | 89 (49) | 98 (55) |
| >61 | 92 (51) | 79 (45) |
| Body mass index, kg/m2 | ||
| ≤24.6 (median) | 91 (52) | 83 (49) |
| >24.6 | 85 (48) | 87 (51) |
| Not available | 5 | 7 |
| ECOG performance status | ||
| 0 | 155 (86) | 151 (85) |
| 1 or 2 | 24 (14) | 25 (15) |
| Not available | 2 | 1 |
| Completeness of surgery | ||
| Complete resection (R0) | 153 (85) | 146 (83) |
| Microscopic residual suspected (R1) |
27 (15) | 30 (17) |
| Not available | 1 | 1 |
| Time from surgery to randomization, days | ||
| ≤56 (median) | 85 (47) | 97 (55) |
| >56 | 95 (53) | 79 (45) |
| Not available | 1 | 1 |
| Tumor diameter, cm | ||
| ≤5.0 | 24 (13) | 16 (9) |
| 5.1-10.0 | 84 (47) | 73 (41) |
| 10.1-15.0 | 44 (24) | 60 (34) |
| >15.0 | 28 (16) | 27 (15) |
| Not available | 1 | 1 |
| Tumor mitotic count per 50 HPFs, local assessment | ||
| ≤5 | 51 (30) | 48 (30) |
| 6-10 | 45 (27) | 50 (31) |
| 11-15 | 21 (12) | 14(9) |
| 16-20 | 8(5) | 13(8) |
| 21-50 | 23 (14) | 26 (16) |
| >50 | 21 (12) | 11 (7) |
| Not available | 12 | 15 |
| Tumor mitotic count per 50 HPFs, central assessment | ||
| ≤5 | 80 (46) | 85 (51) |
| 6-10 | 27 (15) | 25 (15) |
| 11-15 | 19 (11) | 15 (9) |
| 16-20 | 8 (5) | 11 (7) |
| 21-50 | 29 (17) | 26 (16) |
| >50 | 12 (7) | 4 (2) |
| Not available | 6 | 11 |
| Tumor site | ||
| Stomach | 91 (51) | 100 (57) |
| Small intestine | 68 (38) | 55 (31) |
| Colon or rectum | 11 (6) | 15 (9) |
| Other | 10 (6) | 6 (3) |
| Not available | 1 | 1 |
| Tumor rupture prior to or at surgery | ||
| No | 149 (82) | 136 (77) |
| Yes | 32 (18) | 41 (23) |
| Rupture prior to surgery | ||
| No | 160 (89) | 153 (87) |
| Yes | 20 (11) | 23 (13) |
| Not available | 1 | 1 |
| Rupture at surgery | ||
| No | 163 (91) | 152 (86) |
| Yes | 17 (9) | 24 (14) |
| Not available | 1 | 1 |
| Tumor mutation type, central assessment | ||
| KIT exon 11 | 122 (70) | 119 (72) |
| KIT exon 9 | 12 (7) | 14 (8) |
| PDGFRA exon 18b | 20 (11) | 18 (11) |
| Other mutation | 5 (3) | 4 (2) |
| Wild type for KIT | 15 (9) | 10 (6) |
| and PDGFRA | ||
| Not available | 7 | 12 |
Abbreviations: ECOG, Eastern Cooperative Oncology Group; HPF, high-power field of the microscope; PDGFRA, platelet-derived growth factor receptor alpha.
a
The percentages may not sum up to 100 due to rounding.
b
A total of 16 (80%) of the 20 PDGFRA exon 18 mutations in the 12-month group and 13 (72%) of the 18 PDGFRA exon 18 mutations in the 36-month group were D842V substitution mutations.