Table 2. Comparison of baseline clinicopathologic characteristics between MIT and COT groups.
| Characteristics | MIT (n=617) | COT (n=2,674) | P value |
|---|---|---|---|
| Age (years) | 42.8±10.5 (range, 21–80) | 46.9±11.2 (range, 11–79) | <0.001 |
| Female | 519 (84.1) | 1,993 (74.5) | <0.001 |
| Capsular extension | 292 (47.3) | 941 (35.2) | <0.001 |
| Multifocality | 64 (10.4) | 414 (15.5) | 0.001 |
| Hashimoto’s thyroiditis | 167 (27.1) | 787 (29.4) | 0.258 |
| Tumor subtype | 0.874 | ||
| PTC | 606 (98.2) | 2,636 (98.6) | |
| FTC | 11 (1.8) | 38 (1.4) | |
| OP time (min) | 63.5±26.2 (range, 30–343) | 85.3±36.8 (range, 30–561) | <0.001 |
| Tumor size (cm) | 0.8±0.5 | 0.6±0.5 | 0.005 |
| T stage | <0.001 | ||
| T1 | 316 (51.2) | 1,687 (63.1) | |
| T2 | 5 (0.8) | 28 (1.0) | |
| T3 | 290 (47.0) | 952 (35.6) | |
| T4 | 6 (1.0) | 7 (0.3) | |
| N stage | 0.768 | ||
| N0 | 459 (74.4) | 2,007 (75.1) | |
| N1a | 158 (25.6) | 667 (24.9) | |
| TNM stage | <0.001 | ||
| Stage I | 481 (78.2) | 1,941 (72.6) | |
| Stage II | 4 (0.7) | 19 (0.7) | |
| Stage III | 126 (20.4) | 707 (26.4) | |
| Stage IV | 6 (1.0) | 7 (0.3) | |
| Harvested LNs | 3.1±2.6 (range, 0–22) | 5.5±4.0 (range, 0–27) | <0.001 |
| Positive LNs | 0.5±1.0 (range, 0–8) | 0.5±1.1 (range, 0–11) | 0.283 |
Data are expressed as patient’s number (%), or mean ± SD. A statistically significant difference was defined as P<0.05. MIT, minimally invasive thyroidectomy; COT, conventional open thyroidectomy; PTC, papillary thyroid carcinoma; FTC, follicular thyroid carcinoma; OP, operation; T, tumor; N, node; M, metastasis; LN, lymph node; SD, standard deviation.