Table 3.
Clinical characteristics of NPC patients in the training, retrospective validation, and prospective validation cohorts
| Characteristic | Training cohort | Retrospective validation cohort | Prospective validation cohort |
|---|---|---|---|
| Total (cases) | 2716 | 1702 | 1613 |
| Age (years) | |||
| Median (range) | 46 (10–86) | 47 (10–90) | 47 (11–83) |
| Follow-up time (months) | |||
| Median (range) | 68 (1–120) | 68 (1–120) | 41 (1–91) |
| Sex [cases (%)] | |||
| Female | 658 (24.2) | 501 (29.4) | 404 (25.1) |
| Male | 2058 (75.8) | 1201 (70.6) | 1209 (74.9) |
| Clinical stage [cases (%)] | |||
| I | 75 (2.8) | 67 (4.0) | 35 (2.2) |
| II | 549 (20.2) | 388 (22.8) | 104 (6.5) |
| III | 1272 (46.8) | 695 (40.8) | 458 (28.4) |
| IV | 820 (30.2) | 552 (32.4) | 1016 (62.9) |
| Therapeutic modality [cases (%)] | |||
| Radiotherapy alone | 1592 (58.6) | 928 (54.5) | 220 (13.6) |
| Radiochemotherapy | 1124 (41.4) | 774 (45.5) | 1393 (86.4) |
| Proposed classification [cases (%)] | |||
| EC | 1520 (55.9) | 987 (58.0) | 1202 (74.5) |
| MSEC | 598 (22.0) | 420 (24.7) | 229 (14.2) |
| SC | 489 (18.0) | 198 (11.6) | 135 (8.4) |
| SCC | 109 (4.1) | 97 (5.7) | 47 (2.9) |
| WHO classification [case (%)] | |||
| NKUC | 2261 (83.2) | 1425 (83.8) | 1185 (73.5) |
| NKDC | 409 (15.1) | 227 (13.3) | 414 (25.7) |
| KSCC | 46 (1.7) | 50 (2.9) | 14 (0.8) |
| OS rate (%) | |||
| 5-year (95% CI) | 68.7 (66.9–70.5) | 73.3 (71.1–75.4) | 83.5 (81.1–85.6) |
NPC nasopharyngeal carcinoma, EC epithelial carcinoma, SC sarcomatoid carcinoma, MSEC mixed sarcomatoid-epithelial carcinoma, SCC squamous cell carcinoma, WHO World Health Organization, NKUC non-keratinizing undifferentiated carcinoma, NKDC non-keratinizing differentiated carcinoma, KSCC keratinizing squamous cell carcinoma, OS overall survival, CI confidence interval