Table 4 The prognostic factors for unconventional metastatic patients in the SG group
Variables | The overall survival rate | P value | |
|---|---|---|---|
Univariate analysis | Cox modela | ||
Age | Â | 0.347 | NA |
 33–59(16) | 56.3% | ||
 60–87(12) | 50.0% | ||
Gender | Â | 0.541 | NA |
 Male(17) | 58.8% | ||
 Female(11) | 45.5% | ||
Histories of smoking or alcohol | Â | 0.363 | NA |
 Yes(16) | 62.5% | ||
 No(12) | 41.7% | ||
Premalignant mucosal diseases | Â | 0.530 | NA |
 Yes(7) | 57.1% | ||
 No(21) | 52.4% | ||
Primary site | Â | 0.678 | NA |
 Buccal mucosa(1) | 100.0% | ||
 Carcinoma of lip(2) | 100.0% | ||
 Upper gingiva(5) | 60% | ||
 Lower gingiva(2) | None | ||
 Floor of mouth(2) | None | ||
 Tongue(6) | 50.0% | ||
 Hard palate(10) | 60.0% | ||
Unconventional metastatic subsites | Â | 0.810 | NA |
 Buccinator (19) | 57.9% | ||
 Sublingual(8) | 37.5% | ||
 Parotid(1) | 100% | ||
Pathological grade | Â | 0.890 | NA |
 I(4) | 50.0% | ||
 II(19) | 52.6% | ||
 III(5) | 60.0% | ||
Pathological grade is upgraded compared to the last surgery | Â | 0.929 | NA |
 Yes(5) | 60.0% | ||
 No(23) | 52.2% | ||
Number of metastatic lymph nodes in the unconventional subsites | Â | 0.344 | NA |
 1(20) | 60.0% | ||
 2(8) | 37.5% | ||
Lymph nodes size of UMLNs | Â | 0.026 | NA |
 0–3 cm(21) | 61.9% | ||
 > 3 cm(7) | 28.6% | ||
Extranodal extension (ENE) in UMLNs | Â | 0.015 | 0.017 |
 Yes(8) | 25.0% | ||
 No(20) | 65.0% | ||
Contralateral metastasis | Â | 0.006 | NA |
 Yes(7) | 14.3% | ||
 No(21) | 66.7% | ||
Cervical lymph node metastasis | Â | 0.046 | NA |
 Yes(17) | 35.3% | ||
 No(11) | 81.8% | ||
Neck dissections | Â | 0.018 | 0.001 |
 ISND(4) | 75.0% | ||
 IRND(16) | 68.8% | ||
 BND(8) | 12.5% | ||
Extranodal extension (ENE) in cervical lymph nodes | Â | 0.025 | NA |
 Yes(3) | None | ||
 No(25) | 60.0% | ||
Postoperative adjuvant therapies | Â | 0.100 | NA |
 Radiotherapy(15) | 66.7% | ||
 Radio-chemotherapies(9) | 44.4% | ||
 None(4) | 25.0% | ||