Table 1.
Baseline characteristics by clinic site
| Characteristics | Total (N = 366) |
Samsung hospital (n = 193) |
Severance hospital (n = 173) |
2 test P valuec |
|---|---|---|---|---|
| n (%) | n (%) | n (%) | ||
| Age at LA HNSCC diagnosis, years | ||||
| Median | 59 | 60 | 58 | |
| ≤65 | 273 (74.6) | 140 (72.5) | 133 (76.9) | 0.3410 |
| >65 | 93 (25.4) | 53 (27.5) | 40 (23.1) | |
| Sex | ||||
| Female | 62 (16.9) | 32 (27.5) | 30 (17.3) | 0.8464 |
| Male | 304 (83.1) | 161 (72.5) | 143 (82.7) | |
| Smoking status (All tobacco)a | ||||
| Current | 131 (35.8) | 61 (34.5) | 70 (44.6) | 0.1129 |
| Former | 93 (25.4) | 50 (28.2) | 43 (27.4) | |
| Never | 110 (30.1) | 66 (37.3) | 44 (28.0) | |
| Unknown | 32 (8.7) | 16 | 16 | |
| Smoking volume | ||||
| Never smokers | 110 (30.1) | 66 (34.2) | 44 (25.4) | 0.2280 |
| <10 pack-years | 13 (3.6) | 5 (2.9) | 8 (5.6) | |
| ≥10 pack-years | 190 (51.9) | 100 (58.5) | 90 (63.4) | |
| Unknown (among smokers) | 21 (5.7) | 6 | 15 | |
| HPV status | ||||
| Negative | 221 (60.4) | 125 (65.6) | 96 (55.8) | 0.0605 |
| Positive | 142 (38.8) | 66 (34.4) | 76 (44.2) | |
| Unknown | 3 (0.8) | 2 | 1 | |
| Primary HNSCC site | ||||
| Hypopharynx | 40 (10.9) | 14 (7.3) | 26 (15.0) | <0.0001 |
| Larynx | 72 (19.7) | 56 (29.0) | 16 (9.3) | |
| Lip and oral cavity | 88 (24.0) | 41 (21.2) | 47 (27.2) | |
| Oropharynx | 132 (36.1) | 49 (25.4) | 83 (48.0) | |
| Other ill-defined sites in lip, oral cavity, and pharynx | 34 (9.3) | 33 (17.1) | 1 (0.6) | |
| Stage at diagnosisb | ||||
| III | 90 (24.6) | 64 (33.2) | 26 (15.0) | 0.0001 |
| IV A/B | 276 (75.4) | 129 (66.8) | 147 (85.0) | |
| Histologic grade | ||||
| Well differentiated | 87 (23.8) | 53 (31.7) | 34 (20.9) | 0.0700 |
| Moderately differentiated | 185 (50.5) | 85 (50.9) | 100 (61.3) | |
| Poorly differentiated | 58 (15.8) | 29 (17.4) | 29 (17.8) | |
| Unknown | 36 (9.8) | 26 | 10 | |
| ECOG status | ||||
| 0 | 116 (31.7) | 86 (44.6) | 30 (30.0) | 0.0351 |
| 1 | 160 (43.7) | 95 (49.2) | 65 (65.0) | |
| 2+ | 17 (4.6) | 12 (6.2) | 5 (5.0) | |
| Unknown | 73 (19.9) | 0 | 73 | |
| Primary treatment (planned) | ||||
| Definitive CCRT | 19 (5.2) | 8 (4.1) | 11 (6.4) | <0.0001 |
| Surgery + CCRT | 127 (34.7) | 30 (15.5) | 97 (56.1) | |
| Surgery + RT | 191 (52.2) | 132 (68.4) | 59 (34.1) | |
| RT or surgery alone | 29 (7.9) | 23 (11.9) | 6 (3.5) | |
| Tissue sample collected before chemotherapy | ||||
| No | 15 (4.1) | 1 (0.5) | 14 (8.1) | 0.0003 |
| Yes | 351 (95.9) | 192 (99.5) | 159 (91.9) | |
| Neoadjuvant chemotherapy | ||||
| No | 350 (95.6) | 193 (100.0) | 157 (90.8) | <0.0001 |
| Yes | 16 (4.4) | 0 (0.0) | 16 (9.2) |
AJCC, American Joint Committee on Cancer; CCRT, concurrent chemoradiation; ECOG, Eastern Cooperative Oncology Group; HNSCC, head and neck squamous cell carcinoma; HPV, human papillomavirus; LA, locoregionally advanced; RT, radiotherapy.
a
Former smoker is one who quit >1 year before diagnosis; current smoker is one who currently smokes or quit <1 year before diagnosis.
b
According to AJCC seventh edition criteria.20
c
P value is to test the difference in clinicopathologic characteristics between clinical sites; the unknown category was excluded from this calculation.