Table 3.
Risk Factors for LLNM in PTMC Patients
| Variables | LLNM- | LLNM+ | P value | Multivariate Analysis | P value |
|---|---|---|---|---|---|
| n=3430 (%) | n=256 (%) | OR (95% CI) | |||
| Gender | <0.001 | 0.001 | |||
| Female | 2632 (76.7) | 168 (65.6) | 1 | ||
| Male | 798 (23.3) | 88 (34.4) | 1.668 (1.234–2.254) | ||
| Age (year) | 0.207 | ||||
| <55 | 2558 (74.6) | 200 (78.1) | |||
| ≥55 | 872 (25.4) | 56 (21.9) | |||
| Tumor size (mm) | <0.001 | <0.001 | |||
| ≤6.5 | 1915 (55.8) | 67 (26.2) | 1 | ||
| >6.5 | 1515 (44.2) | 189 (73.8) | 2.223 (1.638–3.018) | ||
| CLT | 0.026 | 0.021 | |||
| Absent | 2245 (65.5) | 150 (58.6) | 1 | ||
| Present | 1185 (34.5) | 106 (41.4) | 1.402 (1.053–1.867) | ||
| LVI | <0.001 | <0.001 | |||
| Absent | 3394 (99.0) | 232 (90.6) | 1 | ||
| Present | 36 (1.0) | 24 (9.4) | 4.582 (2.510–8.365) | ||
| Multifocality | <0.001 | 0.308 | |||
| Absent | 2549 (74.3) | 150 (58.6) | 1 | ||
| Present | 881 (25.7) | 106 (41.4) | 1.279 (0.797–2.050) | ||
| Bilaterality | <0.001 | 0.300 | |||
| Absent | 2847 (83.0) | 174 (68.0) | 1 | ||
| Present | 583 (17.0) | 82 (32.0) | 1.308 (0.787–2.173) | ||
| ETE | <0.001 | 0.023 | |||
| Absent | 2627 (76.6) | 152 (59.4) | 1 | ||
| Present | 803 (23.4) | 104 (40.6) | 1.393 (1.046–1.854) | ||
| CLNM | <0.001 | <0.001 | |||
| Absent | 2510 (73.2) | 62 (24.2) | 1 | ||
| Present | 920 (26.8) | 194 (75.8) | 6.212 (4.576–8.433) | ||
| No. CLNs involved > 3 | <0.001* | ||||
| Absent | 756 (82.2) | 110 (56.7) | |||
| Present | 164 (17.8) | 84 (43.3) |
Note: *This P value means the difference between two groups in patients with CLNM.
Abbreviations: LLNM, lateral lymph node metastasis; CLT, chronic lymphocytic thyroiditis; LVI, lymphovascular invasion; ETE, extrathyroidal extension; CLNM, central lymph node metastasis; CLNs, central lymph nodes.