Table 1 Univariable analyses of factors related to level IB LNs metastases at diagnosis in 1438 patients
Variable | Metastasis to level Ib LNs at diagnosis, N (%) | *P | |
|---|---|---|---|
(−), n = 1398 | (+), n = 40 | ||
Sex | Â | Â | Â |
Male | 1052 (75.3) | 33 (82.5) | .294 |
Female | 346 (24.7) | 7 (17.5) | |
Age | Â | Â | Â |
<50 years | 950 (68.0) | 23 (57.5) | .163 |
≥50 years | 448 (32.0) | 17 (42.5) | |
Histologic type | Â | Â | Â |
Keratinizing squamous cell carcinoma | 5 (0.4) | 0 | 1.000 |
Nonkeratinizing carcinoma | 1393 (99.6) | 40 (100.0) | |
T stage |  |  | ’ |
T1 | 247 (17.7) | 5 (12.5) | .537 |
T2 | 207 (14.8) | 6 (15.0) | |
T3 | 679 (48.6) | 18 (45.0) | |
T4 | 265 (19.0) | 11 (27.5) | |
T classification | Â | Â | Â |
T1-3 | 1133 (81.0) | 29 (72.5) | .176 |
T4 | 265 (19.0) | 11 (27.5) | |
Oropharynx involvement | Â | Â | Â |
(−) | 1291 (92.3) | 31 (77.5) | .001 |
(+) | 107 (7.7) | 9 (22.5) | |
Nasal cavity involvement | Â | Â | Â |
(−) | 918 (65.7) | 22 (55.0) | .162 |
(+) | 480 (34.3) | 18 (45.0) | |
N classification | Â | Â | Â |
N0 | 235 (16.8) | 0 | <.001 |
N1 | 823 (58.9) | 19 (47.5) | |
N2 | 216 (15.5) | 13 (32.5) | |
N3 | 124 (8.9) | 8 (20.1) | |
Positive RLNs | Â | Â | Â |
(−) | 387 (27.7) | 3 (7.5) | .005 |
(+) | 1011 (72.3) | 37 (92.5) | |
Positive CLNs | Â | Â | Â |
(−) | 570 (40.8) | 4 (10.0) | <.001 |
(+) | 828 (59.2) | 36 (90.0) | |
LN necrosis | Â | Â | Â |
(−) | 1054 (75.4) | 22 (55.0) | <.001 |
(+) | 344 (24.6) | 18 (45.0) | |
LNs with ES | Â | Â | Â |
(−) | 1051 (75.2) | 26 (65.0) | .143 |
(+) | 347 (24.8) | 14 (35.0) | |
DLN-IIa ≥30 mm or level IIa LNs with ES |  |  | |
(−) | 1247 (89.2) | 34 (85.0) | .435 |
(+) | 151 (10.8) | 6 (15.0) | |
DLN-IIa ≥20 mm or level IIa LNs with ES |  |  | |
(−) | 1113 (79.6) | 19 (47.5) | <.001 |
(+) | 285 (20.4) | 21 (52.5) | |
MAD of LNs ≥30 mm |  |  |  |
(−) | 1196 (85.6) | 26 (65.0) | <.001 |
(+) | 202 (14.4) | 14 (35.0) | |
Positive bilateral CLNs | Â | Â | Â |
(−) | 1121 (80.2) | 20 (50.0) | <.001 |
(+) | 277 (19.8) | 20 (50.0) | Â |
Positive CLNs at supraclavicular fossa | Â | Â | |
(−) | 1318 (94.3) | 21 (80.0) | <.001 |
(+) | 80 (5.7) | 8 (20.0) | |