Clinicopathologic Characteristics of Study Participants
| Entire cohort (n = 473) | pN+ (n = 211) | |||||
| Characteristics | PET-negative (n = 199) | PET-positive (n = 274) | P | PET-negative (n = 47) | PET-positive (n = 164) | P |
| Sex | 0.381 | 0.815 | ||||
| Male | 185 (93.0) | 260 (94.9) | 44 (93.6) | 155 (94.5) | ||
| Female | 14 (7.0) | 14 (5.1) | 3 (6.4) | 9 (5.5) | ||
| Age (y) | 0.974 | 0.970 | ||||
| ≤40 | 38 (19.1) | 52 (19.0) | 9 (19.1) | 31 (18.9) | ||
| >40 | 161 (80.9) | 222 (81.0) | 38 (80.9) | 133 (81.1) | ||
| Clinical N status | <0.001 | <0.001 | ||||
| cN0 | 176 (88.4) | 92 (33.6) | 33 (70.2) | 26 (15.9) | ||
| cN+ | 23 (11.6) | 182 (66.4) | 14 (29.8) | 138 (84.1) | ||
| ND | <0.001 | <0.001 | ||||
| I–III | 194 (97.5) | 213 (77.7) | 44 (93.6) | 111 (67.7) | ||
| I–V | 5 (2.5) | 61 (22.3) | 3 (6.4) | 53 (32.3) | ||
| Treatment | <0.001 | 0.001 | ||||
| Surgery alone | 134 (67.3) | 80 (29.2) | 9 (19.1) | 9 (5.5) | ||
| Surgery plus radiotherapy | 39 (19.6) | 72 (26.3) | 15 (31.9) | 34 (20.7) | ||
| Surgery plus concomitant chemoradiation | 26 (13.1) | 122 (44.5) | 23 (48.9) | 121 (73.8) | ||
| Differentiation | 0.228 | 0.396 | ||||
| Well | 53 (26.6) | 77 (28.1) | 4 (8.5) | 25 (15.2) | ||
| Moderate | 129 (64.8) | 161 (58.8) | 36 (76.6) | 110 (67.1) | ||
| Poor | 17 (8.5) | 36 (13.1) | 7 (14.9) | 29 (17.7) | ||
| Tumor depth (mm) * † | <0.001 | 0.036 | ||||
| <10 | 132 (66.3) | 112 (41.0) | 23 (48.9) | 53 (32.3) | ||
| ≥10 | 67 (33.7) | 161 (59.0) | 24 (51.1) | 111 (67.7) | ||
| Close margins (mm) | 0.587 | 0.286 | ||||
| ≤4 | 12 (6.0) | 20 (7.3) | 5 (10.6) | 10 (6.1) | ||
| >4 | 187 (94.0) | 254 (92.7) | 42 (89.4) | 154 (93.9) | ||
| Pathologic T status | <0.001 | 0.056 | ||||
| pT1–2 | 143 (71.9) | 132 (48.2) | 26 (55.3) | 65 (39.6) | ||
| pT3–4 | 56 (28.1) | 142 (51.8) | 21 (44.7) | 99 (60.4) | ||
| Pathologic N status | <0.001 | |||||
| pN0 | 152 (76.4) | 110 (40.1) | ||||
| pN+ | 47 (23.6) | 164 (59.9) | ||||
| Level IV or V metastases | 0.022 | 0.388 | ||||
| No | 197 (99.0) | 261 (95.3) | 45 (95.7) | 151 (92.1) | ||
| Yes | 2 (1.0) | 13 (4.7) | 2 (4.3) | 13 (7.9) | ||
| pN2c status | 0.002 | 0.090 | ||||
| No | 198 (99.5) | 258 (94.2) | 46 (97.9) | 148 (90.2) | ||
| Yes | 1 (0.5) | 16 (5.8) | 1 (2.1) | 16 (9.8) | ||
| ECS | <0.001 | <0.001 | ||||
| No | 187 (94.0) | 155 (56.6) | 35 (74.5) | 45 (27.4) | ||
| Yes | 12 (6.0) | 119 (43.4) | 12 (25.5) | 119 (72.6) | ||
| pN+ number | <0.001 | 0.001 | ||||
| <5 nodes | 198 (99.5) | 235 (85.8) | 46 (97.9) | 125 (76.2) | ||
| ≥5 nodes | 1 (0.5) | 39 (14.2) | 1 (2.1) | 39 (23.8) | ||
| Bone marrow invasion | 0.019 | 0.190 | ||||
| No | 177 (88.9) | 222 (81.0) | 41 (87.2) | 129 (78.7) | ||
| Yes | 22 (11.1) | 52 (19.0) | 6 (12.8) | 35 (21.3) | ||
| Skin invasion | 0.063 | 0.425 | ||||
| No | 187 (94.0) | 244 (89.1) | 42 (89.4) | 139 (84.8) | ||
| Yes | 12 (6.0) | 30 (10.9) | 5 (10.6) | 25 (15.2) | ||
| Perineural invasion | <0.001 | 0.672 | ||||
| No | 145 (72.9) | 159 (58.0) | 24 (51.1) | 78 (47.6) | ||
| Yes | 54 (27.1) | 115 (42.0) | 23 (48.9) | 86 (52.4) | ||
| Vascular invasion | 0.592 | 0.684 | ||||
| No | 196 (98.5) | 268 (97.8) | 45 (95.7) | 159 (97.0) | ||
| Yes | 3 (1.5) | 6 (2.2) | 2 (4.3) | 5 (3.0) | ||
| Lymph invasion | <0.001 | 0.042 | ||||
| No | 198 (99.5) | 253 (92.3) | 46 (97.9) | 144 (87.8) | ||
| Yes | 1 (0.5) | 21 (7.7) | 1 (2.1) | 20 (12.2) | ||