Table 1 Characteristics of study subjects in the training and testing sets according to case-control status for oral and pharyngeal carcinoma
|  | Training set (n = 147) |  | Testing set (n = 76) |  | ||
|---|---|---|---|---|---|---|
|  | Case (n = 101) | Control (n = 46) | p difference | Case (n = 51) | Control (n = 25) | p difference |
Age, median (range) | 60.0 (23–86) | 60.5 (46–88) | 0.31e | 58.0 (29–78) | 59.0 (32–77) | 0.82e |
Sex | ||||||
 Female | 29 (28.7 %) | 17 (37.0 %) | 0.34f | 16 (31.4 %) | 8 (32.0 %) | >0.99f |
 Male | 72 (71.3 %) | 29 (63.0 %) |  | 35 (68.6 %) | 17 (68.0 %) |  |
Racea | ||||||
 White | 92 (91.1 %) | 44 (95.7 %) | 0.51f | 47 (92.2 %) | 20 (80.0 %) | 0.15f |
 Other | 8 (7.9 %) | 2 (4.3 %) |  | 4 (7.8 %) | 5 (20.0 %) |  |
Smokingb | ||||||
 Never | 30 (31.3 %) | 15 (32.6 %) | >0.99f | 15 (31.3 %) | 14 (56.0 %) | 0.048f |
 Ever | 66 (68.8 %) | 31 (67.4 %) |  | 33 (68.8 %) | 11 (44.0 %) |  |
 Pack-yearsc, median (range) | 31.0 (0.6–120) | 24.0 (0.1–200) | 0.18e | 22.0 (0.9–94) | 13.7 (0.8–62.5) | 0.23e |
Alcohol useb | ||||||
 Non-drinker | 7 (7.4 %) | 7 (15.2 %) | 0.18f | 3 (6.3 %) | 4 (16.0 %) | 0.047f |
 ≤2 drinks/day | 51 (53.7 %) | 27 (58.7 %) |  | 25 (52.1 %) | 17 (68.0 %) |  |
 >2 drinks/day | 37 (38.9 %) | 12 (26.1 %) |  | 20 (41.7 %) | 4 (16.0 %) |  |
HPV serologyd (E6 or E7 antibodies) | ||||||
 Negative | 62 (66.0 %) | – | – | 26 (60.5 %) | – | – |
 Positive | 32 (34.0 %) | – |  | 17 (39.5 %) | – |  |
AJCC stage group | ||||||
 I | 24 (23.8 %) | – | – | 13 (25.5 %) | – | – |
 II | 12 (11.9 %) | – |  | 7 (13.7 %) | – |  |
 III | 13 (12.9 %) | – |  | 5 (9.8 %) | – |  |
 IV | 52 (51.5 %) | – |  | 26 (51.0 %) | – |  |