Table 5 The prognostic factors for unconventional metastatic patients in the RRG group
Variables | The overall survival rate | P value | |
|---|---|---|---|
Univariate analysis | Cox modelb | ||
Age | Â | 0.500 | NA |
 33–59(25) | 16.0% | ||
 60–87(11) | 9.1% | ||
Gender | Â | 0.286 | NA |
 Male(24) | 12.5% | ||
 Female(12) | 16.7% | ||
Histories of smoking and alcohol | 10.0% | 0.248 | NA |
 Yes(20) | 10.0% | ||
 No(16) | 12.5% | ||
Premalignant mucosal diseases | Â | 0.484 | NA |
 Yes(8) | 12.5% | ||
 No(28) | 14.3% | ||
Prior radio- or chemo-therapies | Â | 0.809 | NA |
 Yes(21) | 19.0% | ||
 No(15) | 6.7% | ||
Primary site | Â | 0.838 | NA |
 Buccal mucosa(5) | 40.0% | ||
 Upper gingiva(7) | 14.3% | ||
 Lower gingiva(5) | 20.0% | ||
 Floor of mouth(3) | 33.3% | ||
 Retromolar trigone(8) | None | ||
 Tongue(7) | None | ||
 Hard palate(1) | None | ||
Unconventional metastatic subsites | Â | 0.122 | NA |
 Buccinator (16) | 18.8% | ||
 Sublingual(11) | 9.1% | ||
 Parotida(9) | 11.1% | ||
Pathological grade | Â | 0.172 | NA |
 II(19) | 26.3% | ||
 III(17) | None | ||
Pathological grade is upgraded compared to the last surgery | Â | 0.404 | NA |
 Yes(16) | 6.3% | ||
 No(20) | 20.0% | ||
Number of metastatic lymph nodes in the unconventional subsites | Â | 0.617 | NA |
 1(29) | 13.8% | ||
 2(6) | 16.7% | ||
 3(1) | None | ||
Lymph nodes size of UMLNs | Â | 0.808 | NA |
 0–3 cm(22) | 9.1% | ||
 > 3 cm(14) | 21.4% | ||
Last neck dissections | Â | 0.407 | NA |
 ISND(13) | 7.7% | ||
 IRND(12) | 25.0% | ||
 BND(1) | None | ||
 No treatment(10) | 10.0% | ||
Neck dissections this time | Â | 0.426 | NA |
 ISND(5) | 20.0% | ||
 IRND(7) | 14.3% | ||
 CND(8) | None | ||
 BND(9) | None | ||
 No treatment(7) | 42.9% | ||
Extranodal extension (ENE) in UMLNs | Â | 0.290 | NA |
 Yes(16) | 18.8% | ||
 No(20) | 10.0% | ||
Contralateral metastasis | Â | 0.124 | NA |
 Yes(13) | None | ||
 No(23) | 21.7% | ||
Cervical lymph node metastasis | Â | 0.066 | NA |
 Yes(22) | None | ||
 No(14) | 35.7% | ||
Extranodal extension (ENE) in cervical lymph nodes | Â | 0.030 | 0.030 |
 Yes(10) | None | ||
 No(26) | 19.2% | ||
Postoperative adjuvant therapies | Â | 0.719 | NA |
 Radiotherapy(13) | 15.4% | ||
 Chemotherapy(3) | None | ||
 Radio-chemotherapies(8) | 12.5% | ||
 None(12) | 16.7% | ||