Table 1.
Baseline clinicopathologic characteristics of the patients.
| Characteristic | Number of Patients (n = 170) |
Below N1b (n = 108) |
Above N1b (n = 62) |
p Value |
|---|---|---|---|---|
| Age (mean ± SD) | 49.5 ± 14.5 | 50.5 ± 14.0 | 47.7 ±15.4 | 0.235 |
| Sex (%) | ||||
| Female | 111 (65.3) | 78 (72.2) | 33 (53.2) | 0.012 |
| Male | 59 (34.7) | 30 (27.8) | 29 (46.8) | |
| Tumor type (%) | ||||
| Sporadic | 139 (81.8) | 85 (78.7) | 54 (87.1) | 0.173 |
| Hereditary (MEN-2A) | 31 (18.2) | 23 (21.3) | 9 (12.9) | |
| Primary tumor size (median, IQR) | 1.5 (0.7–2.5) | 1.2 (0.6–1.9) | 2.0 (1.3–3.5) | <0.001 |
| Preoperative serum calcitonin (pg/mL, median, IQR) |
401.0 (96.93–1398.5) |
162.5 (40.8–587.0) |
1201.0 (554.3–2827.0) |
<0.001 |
| Extrathyroidal extension (%) | ||||
| Negative | 125 (73.5) | 98 (90.7) | 27 (43.5) | <0.001 |
| Positive | 45 (26.5) | 10 (9.3) | 35 (56.5) | |
| Number of LNMs (mean ± SD) | 4.9 (8.6) | 0.3 (1.0) | 12.8 (10.1) | <0.001 |
| Extent of LNM (%) | ||||
| Central LNM | 72/170 (42.4) | 17/108 (15.7) | 55/62 (88.7) | <0.001 |
| Ipsilateral lateral LNM | 62/170 (36.5) | 0 | 62/62 (100) | <0.001 |
| Contralateral lateral LNM | 14/170 (8.2) | 0 | 14/62 (22.6) | <0.001 |
| Distant metastasis (%) | 8 /170(4.7) | 0 | 8/62 (12.9) | <0.001 |
| AJCC 8th stage (%) | ||||
| 1 | 68 (40.0) | 68 (63.0) | 0 (0) | <0.001 |
| 2 | 23 (13.5) | 23 (21.3) | 0 (0) | |
| 3 | 17 (10.0) | 17 (15.7) | 0 (0) | |
| 4a | 54 (31.8) | 0 (0) | 53 (85.5) | |
| 4b | 0 (0) | 0 (0) | 1 (1.6) | |
| 4c | 8 (4.7) | 0 | 8 (12.9) |
N1b = Presence of unilateral, bilateral, or contralateral lateral lymph node metastasis; SD = standard deviation; IQR = interquartile range; MEN-2A = multiple endocrine neoplasia type 2A; LNM = lymph node metastasis; AJCC = American Joint Committee on Cancer.