Table 1.
Baseline clinical characteristics relative to surgical extent and tumor multifocality
| Baseline characteristics | Surgical extent | Tumor multifocality | Overall | |||||||||
| Total or near-total (n = 173) | Hemi- or subtotal (n = 134) | P valuea | Multifocal (n = 98) | Solitary (n = 209) | P valuea | |||||||
| Age at operation (> 45 yrs) | 95 | (55) | 54 | (40) | 0.01 | 53 | (54) | 96 | (46) | 0.22 | 149 | (49) |
| Gender (male) | 16 | (9) | 16 | (12) | 0.46 | 9 | (9) | 23 | (11) | 0.69 | 32 | (10) |
| Tumor size | ||||||||||||
| ≤ 0.5 cm | 29 | (17) | 20 | (15) | 0.07 | 9 | (9) | 40 | (19) | 0.04 | 49 | (16) |
| > 0.5 cm and ≤ 0.8 cm | 63 | (36) | 66 | (49) | 40 | (41) | 89 | (43) | 129 | (42) | ||
| > 0.8 cm | 81 | (47) | 48 | (36) | 49 | (50) | 80 | (38) | 129 | (42) | ||
| Multifocal tumor | 84 | (49) | 14 | (10) | < .001 | N/A | N/A | N/A | 98 | (32) | ||
| Bilateral tumor | 57 | (33) | N/A | 57 | (69) | N/A | N/A | 57 | (19) | |||
| Extrathyroid extension | 77 | (45) | 39 | (29) | 0.006 | 47 | (48) | 69 | (33) | 0.02 | 116 | (38) |
| Lymph node metastasis | ||||||||||||
| pNx | 17 | (10) | 27 | (20) | < 0.001 | 13 | (13) | 31 | (15) | 0.03 | 44 | (14) |
| pN0 | 64 | (37) | 60 | (45) | 30 | (31) | 94 | (45) | 124 | (40) | ||
| pN1ab | 68 | (39) | 47 | (35) | 43 | (44) | 72 | (34) | 115 | (37) | ||
| pN1bc | 24 | (14) | 0 | 12 | (12) | 12 | (6) | 24 | (8) | |||
| Remnant ablation | 163 | (94) | N/A | 81 | (83) | 82 | (39) | < .001 | 163 | (53) | ||
| Total or near-total thyroidectomy | N/A | N/A | 84 | (86) | 89 | (43) | < .001 | 173 | (56) | |||
a by Fisher's exact test except for tumor size and lymph node metastasis; by the chi-squared test for tumor size and lymph node metastasis.
b Metastasis to level VI lymph nodes (pretracheal, paratracheal, and prelaryngeal/Delphian), classified as N1a in the 2002 TNM staging.
c Metastasis to unilateral, bilateral, or contralateral cervical superior mediastinal lymph nodes, classified as N1b in the 2002 TNM staging.
Percentages are given in parentheses; N/A, not applicable.