Table 1.
Baseline characteristics of 4469 NPC patients at primary diagnosis
| Characteristic | Total N = 4469 (%) |
PET/CT group N = 1171 (%) |
CWU group N = 3298 (%) |
|---|---|---|---|
| Gender | |||
| Male | 3269 (73.15) | 871 (74.38) | 2398 (72.71) |
| Female | 1200 (26.85) | 300 (25.62) | 900 (27.29) |
| Age | |||
| ≥ 50 | 2122 (47.48) | 535 (45.69) | 1587 (48.12) |
| < 50 | 2347 (52.52) | 636 (54.31) | 1711 (51.88) |
| T stage | |||
| T1 | 820 (18.35) | 227 (19.39) | 593 (17.98) |
| T2 | 793 (17.74) | 212 (18.10) | 581 (17.62) |
| T3 | 1627 (36.41) | 468 (39.97) | 1159 (35.14) |
| T4 | 1229 (27.50) | 264 (22.54) | 965 (29.26) |
| N stage | |||
| N0 | 375 (8.39) | 95 (8.11) | 280 (8.49) |
| N1 | 1593 (35.65) | 351 (29.97) | 1242 (37.66) |
| N2 | 1569 (35.11) | 425 (36.29) | 1144 (34.69) |
| N3 | 932 (20.85) | 300 (25.62) | 632 (19.16) |
| M stage | |||
| M0 | 4225 (94.54) | 1084 (92.57) | 3141 (95.24) |
| M1 | 244 (5.46) | 87 (7.43) | 157 (4.76) |
| Plasma EBV DNA | |||
| Low* | 3553 (79.50) | 859 (73.36) | 2694 (81.69) |
| High** | 916 (20.50) | 312 (26.64) | 604 (18.31) |
EBV, Epstein-Barr virus
*Low EBV DNA level of < 14,650 copies/ml
**High EBV DNA level of ≥ 14,650 copies/ml