Table 4.
Subgroup analyses of association of clinical recurrence in 251 patients with PTMC according to surgical extent after excluding patients without pathologic N staging information
| Baseline characteristics | Patients with total or near-total thyroidectomy (n = 150) | Patients with hemi- or subtotal thyroidectomy (n = 101) | Overall (n = 251) | ||||||
| HR | 95% CI | P | HR | 95% CI | P | HR | 95% CI | P | |
| Age at operation | |||||||||
| ≤ 45 yrs | 1.75 | 0.41–7.39 | 0.45 | INF | NC | 0.99 | 2.38 | 0.63–8.98 | 0.20 |
| > 45 yrs | 1.00 | - | - | 1.00 | - | - | 1.00 | - | - |
| Gender | |||||||||
| Men | 5.35 | 1.28–22.4 | 0.02 | 24.2 | 2.17–270 | 0.01 | 7.59 | 2.31–25.0 | 0.001 |
| Women | 1.00 | - | - | 1.00 | - | - | 1.00 | - | - |
| Tumor size | |||||||||
| Per 1 mm increase | 1.17 | 0.79–1.72 | 0.44 | 1.36 | .0.67–2.76 | 0.4 | 1.23 | 0.86–1.74 | 0.26 |
| Multifocality | |||||||||
| Solitary tumor | 1.58 | 0.38–6.62 | 0.53 | 0.18 | 0.02–1.93 | 0.16 | 0.9 | 0.26–3.08 | 0.86 |
| Multifocal tumor | 1.00 | - | - | 1.00 | - | - | 1.00 | - | - |
| Extrathyroid extension | |||||||||
| Absent | 0.53 | 0.13–2.23 | 0.39 | INF | NC | 1 | 0.77 | 0.23–2.52 | 0.66 |
| Present | 1.00 | - | - | 1.00 | - | - | 1.00 | - | - |
| Lymph node metastasis | 0.04 | 1 | 0.03 | ||||||
| pN0 | 0 | NC | 1 | 0 | NC | 0.99 | 0 | NC | 0.99 |
| pN1aa | 1.00 | - | - | 1.00 | - | - | 1.00 | - | - |
| pN1bb | 8.25 | 1.66–40.9 | 0.01 | N/A | 5.14 | 1.56–17.0 | 0.007 | ||
| Bilaterality | |||||||||
| Unilateral tumor | 0.74 | 0.18–3.11 | 0.69 | N/A | 0.65 | 0.17–2.47 | 0.53 | ||
| Bilateral tumor | 1.00 | - | - | 1.00 | - | - | |||
| Remnant ablation | |||||||||
| Not done | 0 | NC | 1 | N/A | N/A | ||||
| Done | 1.00 | - | - | ||||||
a Metastases to level VI lymph nodes (pretracheal, paratracheal, and prelaryngeal/Delphian lymph nodes), classified as N1a in the 2002 TNM staging.
b Metastases to unilateral, bilateral, or contralateral cervical superior mediastinal lymph nodes, classified as N1b in the 2002 TNM staging.
Percent recurrence rates were given in parentheses; CI, confidence interval; N/A, not applicable; INF, infinite; NC, cannot calculate; HR, hazard ratio.