Table 1. Patient Characteristics (N = 899).
| No. (%) | P value | ||||
|---|---|---|---|---|---|
| Training (MDACC, n = 335) | Validation (MDACC, n = 96) | Internal test (MDACC, n = 48) | External test (BWH, n = 420) | ||
| Age, median (range), y | 57 (24-83) | 58 (29-81) | 59.5 (41-87) | 59 (24-87) | .37a |
| Sex | |||||
| Female | 41 (12.2) | 16 (16.7) | 8 (16.7) | 75 (17.9) | .32b |
| Male | 291 (86.9) | 80 (83.3) | 40 (83.3) | 344 (81.9) | |
| Unspecified | 3 (0.9) | 0 | 0 | 1 (0.2) | |
| Smoking status | |||||
| Current | 68 (20.3) | 19 (19.8) | 11 (22.9) | 55 (13.1) | <.001b |
| Former | 95 (28.4) | 40 (41.7) | 17 (35.4) | 217 (51.7) | |
| Never | 103 (30.7) | 33 (34.4) | 17 (35.4) | 145 (34.5) | |
| Unspecified | 67 (20.0) | 4 (4.2) | 3 (6.2) | 3 (0.7) | |
| Primary cancer site | |||||
| Oropharynx | 309 (92.2) | 92 (95.8) | 45 (93.8) | 314 (74.8) | <.001b |
| Nasopharynx | 1 (0.3) | 0 | 0 | 0 | |
| Larynx or hypopharynx | 2 (0.6) | 0 | 0 | 76 (18.1) | |
| Oral cavity | 2 (0.6) | 0 | 0 | 0 | |
| Unknown or other | 19 (5.7) | 4 (4.2) | 3 (6.2) | 30 (7.1) | |
| AJCC stage | |||||
| I | 3 (0.9) | 1 (1.0) | 0 | 12 (2.9) | .001b |
| II | 11 (3.3) | 3 (3.1) | 2 (4.2) | 34 (8.1) | |
| III | 42 (12.5) | 16 (16.7) | 12 (25.0) | 75 (17.9) | |
| IV | 266 (79.4) | 72 (75.0) | 31 (64.6) | 295 (70.2) | |
| Unspecified | 13 (3.9) | 4 (4.2) | 3 (6.2) | 4 (1.0) | |
| HPV p16 statusc | |||||
| Negative | 19 (5.7) | 9 (9.4) | 9 (18.8) | 49 (11.7) | <.001b |
| Positive | 98 (29.3) | 76 (79.2) | 36 (75.0) | 224 (53.3) | |
| Unspecified | 218 (65.1) | 11 (11.5) | 3 (6.2) | 147 (35.0) | |
| T stage | |||||
| T0 | 2 (0.6) | 0 | 0 | 0 | .24b |
| T1 | 56 (16.7) | 20 (20.8) | 11 (22.9) | 89 (21.2) | |
| T2 | 143 (42.7) | 35 (36.5) | 17 (35.4) | 160 (38.1) | |
| T3 | 77 (23.0) | 22 (22.9) | 10 (20.8) | 109 (26.0) | |
| T4 | 44 (13.1) | 15 (15.6) | 7 (14.6) | 57 (13.6) | |
| Unspecified | 13 (3.9) | 4 (4.2) | 3 (6.2) | 5 (1.2) | |
| N stage | |||||
| N0 | 33 (9.9) | 9 (9.4) | 5 (10.4) | 85 (20.2) | <.001b |
| N1 | 31 (9.3) | 13 (13.5) | 9 (18.8) | 52 (12.4) | |
| N2 | 246 (74.3) | 68 (70.8) | 31 (64.6) | 247 (58.8) | |
| N3 | 12 (3.6) | 2 (2.1) | 0 | 31 (7.4) | |
| Unspecified | 13 (3.9) | 4 (4.2) | 3 (6.2) | 5 (1.2) | |
Abbreviations: AJCC, American Joint Committee on Cancer (7th ed); BWH, Brigham and Women’s Hospital; HPV, human papillomavirus; MDACC, MD Anderson Cancer Center.
a
Kruskal-Wallis rank sum test.
b
Fisher exact test for differences among the data sets.
c
Patients with nonoropharyngeal carcinoma who did not undergo HPV p16 testing were coded as negative, given the very low incidence of HPV p16-positive tumors in these disease sites.