Table 5.
Univariate and multivariate analysis of significant prognostic factors associated with overall survival in patients with nasopharyngeal carcinoma
| No. of patients (%) | No. of patients suffered SPMs (%) | p-valuea) | HR (95% CI) | |
|---|---|---|---|---|
| Univariate analysis | ||||
| Sex | ||||
| Male | 4,728 (74.1) | 159 (84.1) | 0.042 | 1.285 (1.009-1.638) |
| Female | 1,649 (25.9) | 30 (15.9) | Reference | |
| Age (yr) | ||||
| ≤ 50 | 3,377 (53.0) | 75 (39.7) | Reference | |
| > 50 | 3,000 (47.0) | 114 (60.3) | 0.001 | 1.414 (1.159-1.725) |
| T category | ||||
| T1-2 | 2,187 (34.3) | 53 (28.0) | Reference | |
| T3-4 | 4,190 (65.7) | 136 (72.0) | < 0.001 | 3.246 (2.461-4.281) |
| N category | ||||
| N0-1 | 3,992 (62.6) | 105 (55.6) | Reference | |
| N2-3 | 2,385 (37.4) | 84 (44.4) | 0.001 | 1.397 (1.143-1.706) |
| History of smoking | ||||
| No | 4,333 (67.9) | 107 (56.6) | Reference | |
| Yes | 2,044 (32.1) | 82 (43.4) | 0.790 | 1.029 (0.833-1.271) |
| Drinking status | ||||
| No | 5,646 (88.5) | 164 (86.8) | Reference | |
| Yes | 731 (11.5) | 25 (13.2) | 0.754 | 0.950 (0.687-1.312) |
| Chemotherapy | ||||
| No | 1,781 (27.9) | 41 (21.7) | Reference | |
| Yes | 4,596 (72.1) | 148 (78.3) | < 0.001 | 2.156 (1.641-2.834) |
| Re-irradiation | ||||
| No | 6,222 (97.6) | 182 (96.3) | Reference | |
| Yes | 155 (2.4) | 7 (3.7) | 0.005 | 2.008(1.235-3.266) |
| Radiation dose (Gy) | ||||
| ≥ 70 | 3,243 (50.9) | 94 (49.7) | 0.820 | 1.023(0.838-1.250) |
| < 70 | 3,134 (49.1) | 95 (50.3) | Reference | |
| Secondary primary malignancies | ||||
| No | 6,188 (97.0) | - | Reference | |
| Yes | 189 (3.0) | - | < 0.001 | 4.022 (2.889-5.600) |
| Multivariate analysis | ||||
| Sex | ||||
| Male | 4,728 (74.1) | 159 (84.1) | 0.147 | 1.197 (0.939-1.527) |
| Female | 1,649 (25.9) | 30 (15.9) | Reference | |
| Age (yr) | ||||
| ≤ 50 | 3,377 (53.0) | 75 (39.7) | Reference | |
| > 50 | 3,000 (47.0) | 114 (60.3) | 0.003 | 1.361 (1.114-1.663) |
| T category | ||||
| T1-2 | 4,333 (67.9) | 107 (56.6) | Reference | |
| T3-4 | 2,044 (32.1) | 82 (43.4) | < 0.001 | 2.904 (2.197-3.839) |
| N category | ||||
| N0-1 | 3,992 (62.6) | 105 (55.6) | Reference | |
| N2-3 | 2,385 (37.4) | 84 (44.4) | 0.024 | 1.260(1.030-1.541) |
| Chemotherapy | ||||
| No | 1,781 (27.9) | 41 (21.7) | Reference | |
| Yes | 4,596 (72.1) | 148 (78.3) | < 0.001 | 1.716 (1.301-2.263) |
| Re-irradiation | ||||
| No | 6,222 (97.6) | 182 (96.3) | Reference | |
| Yes | 155 (2.4) | 7 (3.7) | 0.008 | 1.934 (1.188-3.149) |
| Secondary primary malignancies | ||||
| No | 6,188 (97.0) | - | Reference | |
| Yes | 189 (3.0) | - | < 0.001 | 3.560 (2.552-4.967) |
SPM, second primary malignancy; HR, hazard ratio; CI, confidence interval.
a)
All factors that had a p-value of < 0.05 in Cox proportional hazards model univariate analysis were included in Cox proportional hazards model multivariate analysis to determine independent factors for overall survival. A p-value of 0.05 or less (in a two-sided test) was considered statistically significant.