Table 1.
Patient characteristics
| Total ACTS-GC population | Biomarker study subpopulation | |||||
|---|---|---|---|---|---|---|
| S-1 (N = 529) | Surgery only (N = 530) | P valuea | S-1 (N = 415) | Surgery only (N = 414) | P valuea | |
| Sex, no. (%) | ||||||
| Male | 367 (69.4) | 369 (69.6) | 0.98 | 282 (68.0) | 283 (68.4) | 0.90 |
| Female | 162 (30.6) | 161 (30.4) | 133 (32.0) | 131 (31.6) | ||
| Age, no. (%) | ||||||
| <60 years | 199 (37.6) | 195 (36.8) | 0.86 | 160 (38.6) | 158 (38.2) | 0.72 |
| 60–69 years | 193 (36.5) | 215 (40.6) | 149 (35.9) | 161 (38.9) | ||
| 70–80 years | 137 (25.9) | 120 (22.6) | 106 (25.5) | 95 (22.9) | ||
| Median (years) | 63 | 63 | 63 | 62 | ||
| Range (years) | 27–80 | 33–80 | 27–80 | 33–80 | ||
| Tumor stage, no. (%) | ||||||
| T1 | 1 (0.2) | 0 (0) | 0.81 | 1 (0) | 0 (0) | 0.93 |
| T2 | 289 (54.6) | 286 (54.0) | 222 (53.5) | 223 (53.9) | ||
| T3 | 225 (42.5) | 232 (43.8) | 180 (43.5) | 182 (44.0) | ||
| T4 | 14 (2.6) | 12 (2.3) | 12 (2.9) | 9 (2.2) | ||
| Nodal stage, no. (%)b | ||||||
| N0 | 51 (9.6) | 64 (12.1) | 0.72 | 40 (9.6) | 52 (12.6) | 0.52 |
| N1 | 296 (56.0) | 281 (53.0) | 233 (56.1) | 222 (53.6) | ||
| N2 | 182 (34.4) | 185 (34.9) | 142 (34.2) | 140 (33.8) | ||
| N3 | 0 (0) | 0 (0) | 0 (0) | 0 (0) | ||
| Lymph-node metastases, no. (%) | ||||||
| 0 | 51 (9.6) | 64 (12.1) | 0.37 | 40 (9.6) | 52 (12.6) | 0.18 |
| 1–6 | 331 (62.6) | 325 (61.3) | 254 (61.2) | 254 (61.4) | ||
| 7–15 | 117 (22.1) | 113 (21.3) | 97 (23.4) | 85 (20.5) | ||
| ≥16 | 30 (5.7) | 28 (5.3) | 24 (5.8) | 23 (5.6) | ||
| Cancer stage, no. (%)c | ||||||
| II | 236 (44.6) | 238 (44.9) | 0.78 | 183 (44.1) | 189 (45.7) | 0.48 |
| IIIA | 202 (38.2) | 207 (39.1) | 159 (38.3) | 162 (39.1) | ||
| IIIB | 90 (17.0) | 85 (16.0) | 73 (17.6) | 63 (15.2) | ||
| IV | 1 (0.2) | 0 (0) | 0 (0) | 0 (0) | ||
| Histologic type, no. (%)d | ||||||
| Differentiated | 214 (41.6) | 209 (40.3) | 0.73 | 166 (40.0) | 166 (40.1) | 0.91 |
| Undifferentiated | 301 (58.4) | 307 (59.7) | 249 (60.0) | 245 (59.2) | ||
| TS expression level, no. (%)e | ||||||
| Low | – | – | – | 138 (34.3) | 134 (33.0) | 0.72 |
| Intermediate | – | – | 137 (34.1) | 131 (32.3) | ||
| High | – | – | 127 (31.6) | 141 (34.7) | ||
| DPD expression level, no. (%)e | ||||||
| Low | – | – | – | 136 (33.9) | 133 (32.8) | 0.60 |
| Intermediate | – | – | 135 (33.7) | 135 (33.3) | ||
| High | – | – | 130 (32.4) | 138 (34.0) | ||
| TP expression level, no. (%)e | ||||||
| Low | – | – | – | 129 (32.2) | 140 (34.5) | 0.80 |
| Intermediate | – | – | 131 (32.7) | 139 (34.2) | ||
| High | – | – | 141 (35.2) | 127 (31.3) | ||
| OPRT expression level, no. (%)e | ||||||
| Low | – | – | – | 129 (32.2) | 140 (34.5) | 0.23 |
| Intermediate | – | – | 131 (32.7) | 140 (34.5) | ||
| High | – | – | 141 (35.2) | 126 (31.0) | ||
Characteristics of all ACTS-GC patients can be found in the literature [2]
a P values for sex and histologic type were calculated using the chi-square test. P values for age, tumor stage, nodal stage, number of lymph-node metastases, cancer stage (Japanese classifications), and gene expression level were calculated using the Wilcoxon test
bNodal stages were defined according to the Japanese classification as follows: N0, no evidence of lymph-node metastasis; N1, metastasis to group 1 lymph nodes; N2, metastasis to group 2 lymph nodes; N3, metastasis to group 3 lymph nodes. Groups 1, 2, and 3 are regional lymph-node classifications defined according to the location of the primary tumor and based on the results of studies of lymphatic flow at various tumor sites and the observed survival associated with metastasis at each nodal station (i.e., position in relation to primary node)
cCancer stages were defined according to the Japanese classification as follows: stage IA, T1N0; stage IB, T1N1 or T2N0; stage II, T1N2, T2N1, or T3N0; stage IIIA, T2N2, T3N1, or T4N0; stage IIIB, T3N2 or T4N1; stage IV, T4N2, any T stage with N3 or distant metastasis
dIn the total ACTS-GC population, histologic type was classified for eligible patients (N = 1,034). In the surgery-only group of the biomarker study population, cancers could not be classified as differentiated or undifferentiated in three patients
eGene expression levels were undetectable for some of the samples, as shown in Fig. 1