Table 1. Baseline characteristics of nasopharyngeal carcinoma patients treated with intensity-modulated radiotherapy or two-dimensional conventional radiotherapy.
| The original unmatched cohort | The propensity-matched cohort | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| IMRT (N=316) | 2DCRT (N=882) | P | Standardized difference | IMRT (N=302) | 2DCRT (N=302) | P | Standardized difference | |||||
| No. | % | No. | % | No. | % | No. | % | |||||
| Age | 0.005 | 0.182 | 0.702 | 0.031 | ||||||||
| Mean | 47.41 | 49.67 | 47.61 | 47.98 | ||||||||
| SD | 12.65 | 12.14 | 12.71 | 11.05 | ||||||||
| Median | 46.00 | 49.00 | 46.00 | 47.00 | ||||||||
| Sex | 0.217 | 0.082 | 0.771 | 0.024 | ||||||||
| Male | 244 | 77.2 | 650 | 73.7 | 232 | 76.8 | 235 | 77.8 | ||||
| Female | 72 | 22.8 | 232 | 26.3 | 70 | 23.2 | 67 | 22.2 | ||||
| Histology* | 0.123 | 0.105 | 0.513 | 0.053 | ||||||||
| II | 18 | 5.7 | 74 | 8.4 | 18 | 6.0 | 22 | 7.3 | ||||
| III | 298 | 94.3 | 808 | 91.6 | 284 | 94.0 | 280 | 92.7 | ||||
| VCA-IgA† | 0.229 | 0.951 | ||||||||||
| <80 | 82 | 25.9 | 201 | 22.8 | 0.074 | 80 | 26.5 | 77 | 25.5 | 0.023 | ||
| 80-320 | 127 | 40.2 | 336 | 38.1 | 0.043 | 118 | 39.1 | 118 | 39.1 | 0.000 | ||
| ≥320 | 107 | 33.9 | 345 | 39.1 | 0.109 | 104 | 34.4 | 107 | 35.4 | 0.021 | ||
| EA-IgA† | 0.006 | 0.715 | ||||||||||
| <10 | 138 | 43.7 | 302 | 34.2 | 0.194 | 126 | 41.7 | 123 | 40.7 | 0.020 | ||
| 10-40 | 103 | 32.6 | 305 | 34.6 | 0.042 | 102 | 33.8 | 111 | 36.8 | 0.062 | ||
| ≥40 | 75 | 23.7 | 275 | 31.2 | 0.167 | 74 | 24.5 | 68 | 22.5 | 0.047 | ||
| T-stage | 0.076 | 0.635 | ||||||||||
| T1 | 133 | 42.1 | 317 | 35.9 | 0.126 | 127 | 42.1 | 122 | 40.4 | 0.034 | ||
| T2 | 98 | 31.0 | 279 | 31.6 | 0.013 | 92 | 30.5 | 99 | 32.8 | 0.050 | ||
| T3 | 66 | 20.9 | 197 | 22.3 | 0.035 | 64 | 21.2 | 56 | 18.5 | 0.066 | ||
| T4 | 19 | 6.0 | 89 | 10.1 | 0.150 | 19 | 6.3 | 25 | 8.3 | 0.077 | ||
| N-stage | <0.001 | 0.700 | ||||||||||
| N0 | 169 | 53.5 | 369 | 41.8 | 0.235 | 162 | 53.6 | 155 | 51.3 | 0.046 | ||
| N1 | 120 | 38.0 | 443 | 50.2 | 0.249 | 115 | 38.1 | 126 | 41.7 | 0.074 | ||
| N2 | 22 | 7.0 | 68 | 7.7 | 0.029 | 21 | 7.0 | 19 | 6.3 | 0.027 | ||
| N3 | 5 | 1.6 | 2 | 0.2 | 0.144 | 4 | 1.3 | 2 | 0.7 | 0.067 | ||
| Clinical stage | 0.004 | 0.671 | ||||||||||
| I | 96 | 30.4 | 181 | 20.5 | 0.228 | 91 | 30.1 | 82 | 27.2 | 0.066 | ||
| II | 120 | 38.0 | 377 | 42.7 | 0.097 | 114 | 37.7 | 125 | 41.1 | 0.075 | ||
| III | 76 | 24.1 | 233 | 26.4 | 0.055 | 74 | 24.5 | 68 | 22.5 | 0.047 | ||
| IV | 24 | 7.6 | 91 | 10.3 | 0.095 | 23 | 7.6 | 27 | 8.9 | 0.048 | ||
Abbreviations: IMRT = intensity-modulated radiotherapy, 2DCRT = two-dimensional conventional radiotherapy, SD = standard deviation, VCA = viral capsid antigen, EA = early antigen, IgA = immunoglobulin A
*
Based on the criteria of WHO histological type (1991): II - Differentiated non-keratinising carcinoma, III - Undifferentiated non-keratinising carcinoma
†
In accordance with the criteria adopted in previous studies