Clinicopathological and Survival Outcomes of Well-Differentiated Thyroid Carcinoma Undergoing Dedifferentiation: A Retrospective Study from FUSCC

Table 2

Risk factors for decreased cause-specific survival in WDTC patients harboring dedifferentiated phenotype.

Variables	Univariate analysis			Multivariate analysis
	value	HR	95.0% CI for HR	value	HR	95.0% CI for HR
Gender
Female		1
Male	0.134	1.977	0.810–4.822
Age	0.013	1.041	1.009–1.076	0.488	1.014	0.974–1.056
Maximum size	0.113	1.233	0.952–1.597
ETE
No		1
Yes	0.396	0.620	0.205–1.870
Histological subtypes of WDTC
FTC		1
PTC	0.251	2.352	0.545–10.144
Dedifferentiated site
Thyroid		1			1
Metastatic site	0.052	2.531	0.992–6.458	0.337	1.656	0.592–4.633
Thyroid and metastatic site	0.052	3.805	0.991–14.609	0.642	1.510	0.266–8.569
Dedifferentiated components
PDTC		1			1
ATC	0.011	3.227	1.308–7.961	0.033	3.732	1.116–12.478
LNM
No		1
Yes	0.322	1.669	0.606–4.4598
DM
No		1			1
Yes	0.056	2.421	0.976–6.005	0.367	1.707	0.534–5.463
Adjuvant therapy
No		1			1
Yes	0.016	3.035	1.277–7.508	0.046	2.715	1.017–7.249

Bold type indicates statistical significance. WDTC: well-differentiated thyroid cancer; HR: hazard ratio; CI: confidence interval; ETE: extrathyroidal extension; FTC: follicular thyroid cancer; PTC: papillary thyroid cancer; PDTC: poorly differentiated thyroid cancer; ATC: anaplastic thyroid cancer; LNM: lymph node metastasis; DM: distant metastasis.