Table 3.

Multivariate analysis using Cox proportional hazard model for recurrence-free survival.

Clinico-pathological variables	Recurrence-free survival
	Hazard ratio	95% Confidence interval	p-value
Age
≥55 years (vs. <55 years)	2.66	1.91–3.64	<0.0001
Sex
Male (vs. Female)	1.58	1.20–2.06	0.0011
Histology
Aggressive variants (vs. non-aggressive variants)	0.98	0.66–1.41	0.9003
Tumor laterality
Bilateral (vs. Unilateral)	1.56	1.03–2.44	0.0366
Tumor focality
Multifocal (vs. Unifocal)	0.73	0.47–1.10	0.1325
Extrathyroidal extension
Present (vs. Absent)	1.20	0.87–1.66	0.2616
Lymphovascular invasion
Present (vs. Absent)	0.96	0.68–1.33	0.7948
pT
T3–4 (vs. T1–2)	1.02	0.76–1.35	0.9093
Lymph node metastasis
Present (vs. Absent)	1.76	1.31–2.40	0.0002
Distant metastasis
Present (vs. Absent)	5.34	3.46–8.09	< 0.0001
TNM stage
III–IV (vs. I–II)	0.50	0.28–0.86	0.0123
ATA risk category
Low risk	Reference
Intermediate risk	1.47	0.76–3.01	0.2579
High risk	2.79	1.45–5.76	0.0016