Table 3.
Univariate Analysis of Risk Factors Related to Level V Lymph Node Metastasis in PTC
| Parameter | Level V Lymph Node Metastases | P-value | |
|---|---|---|---|
| Present, n (%) | Absent, n (%) | ||
| Total | 37(14.7) | 215(85.3) | |
| Sex | |||
| Male | 14(37.8) | 62(28.8) | 0.271 |
| Female | 23(62.2) | 153(71.2) | |
| Age (Mean ± SD) | 37.811±14.966 | 39.856±11.248 | 0.432a |
| ≥55 | 4(10.8) | 19(8.8) | 0.700 |
| ˂55 | 33(89.2) | 196(91.2) | |
| TSH levels | |||
| Low | 2(5.4) | 4(1.9) | 0.052 |
| Normal | 25(67.6) | 184(85.6) | |
| High | 10(27.0) | 27(12.6) | |
| Lymphocytic thyroiditis | 19(51.4) | 70(32.6) | 0.027b |
| Tumor size (Mean ± SD, cm) | 2.695±1.185 | 1.859±1.217 | ˂0.001a |
| ≤2.5 | 13(35.1) | 156(72.6) | ˂0.001b |
| >2.5 | 24(64.9) | 59(27.4) | |
| Pure solid on neck US | 35(94.6) | 209(97.2) | 0.402 |
| Echogenicity of the tumor on neck US | |||
| Hypoechoic | 31(83.8) | 192(89.3) | 0.331 |
| Smooth margin of the tumor on US | 31(83.8) | 151(70.2) | 0.089 |
| Calcification of the tumor on neck US | 37(100) | 196(91.2) | 0.060 |
| Multifocality | 21(56.8) | 104(48.4) | 0.346 |
| Capsule invasion | 11(29.7) | 58(27.0) | 0.729 |
| Bilateral tumor | 15(40.5) | 76(35.3) | 0.544 |
| CLNM | 35(94.6) | 170(79.1) | 0.025b |
| Ipsilateral | 34 (79.1) | 170 (91.9) | 0.067 |
| Contralateral | 8(21.6) | 16(7.4) | 0.007b |
| Bilateral | 15(40.5) | 40(18.6) | 0.003b |
| Number of CLNM (Mean ± SD) | 7.649±6.845 | 3.707±3.713 | 0.002a |
| LLNM | 37(100) | 171(79.5) | 0.002b |
| Level II | 25(67.6) | 64(29.8) | ˂0.001b |
| Level III | 32(86.5) | 116(54.0) | ˂0.001b |
| Level IV | 29(78.4) | 148(68.8) | 0.241 |
| Level II+III | 21(56.8) | 52(24.2) | ˂0.001b |
| Level III+IV | 26(70.3) | 92(42.8) | 0.002b |
| Level II+III+IV | 17(45.9) | 44(20.5) | 0.001b |
Notes: Variables with statistical significance were shown in bold. aThe Student’s t-test was adopted; bThe Wilcoxon rank-sum test was adopted.
Abbreviations: PTC, papillary thyroid carcinoma; SD, standard deviation; TSH, thyroid-stimulating hormone; US, ultrasonography; CLNM, central lymph node metastases; LLNM, lateral lymph node metastasis.