Table 4.

Univariate and multivariate Cox regression analysis of CSS in patients with PTMC

Independent variable	Univariate		Multivariate
	HR (95% CI)	P-value	HR (95% CI)	P-value
Sex (female vs male)	0.281 (0.169–0.465)	0.001	0.544 (0.321–0.923)	0.024
Age (≥45 vs <45 years)	5.709 (2.287–14.253)	0.001	7.419 (2.898–18.990)	0.001
Race
Black	1 (reference)		1 (reference)
White	3.749 (0.519–27.101)	0.190	2.052 (0.281–15.007)	0.479
Othera	4.117 (0.496–34.199)	0.190	2.319 (0.275–19.548)	0.439
Size	1.054 (0.969–1.147)	0.222	1.001 (0.914–1.096)	0.989
Histology (FV-PTMC vs PTMC)	0.721 (0.391–1.331)	0.295	0.845 (0.452–1.577)	0.596
Multifocality	1.608 (0.972–2.661)	0.065	0.938 (0.543–1.621)	0.819
ETE
Negative	1 (reference)		1 (reference)
Capsule	0.759 (0.104–5.513)	0.785	0.625 (0.085–4.564)	0.643
Minimal	3.262 (1.531–6.948)	0.002	1.358 (0.604–3.053)	0.458
Gross	38.880 (19.504–77.508)	0.001	5.844 (2.617–13.051)	0.001
CLNM	1.840 (0.837–4.043)	0.129	2.345 (0.989–5.563)	0.053
LLNM	10.004 (5.960–16.792)	0.001	4.881 (2.496–9.544)	0.001
Metastasisb	85.311 (45.373–160.404)	0.001	18.051 (8.732–37.314)	0.001
TT	1.318 (0.701–2.479)	0.391	0.794 (0.396–1.595)	0.518
Radioisotopes	2.637 (0.535–4.529)	0.068	1.563 (0.841–2.904)	0.158

Notes:

^aIncluding American Indian/Alaska Native and Asian/Pacific Islander.

^bIncluding the lungs, bones, and brains.

Abbreviations: CSS, cancer-specific survival; PTMC, papillary thyroid microcarcinoma; HR, hazard ratio; CI, confidence interval; FV-PTMC, follicular variant of papillary thyroid microcarcinoma; ETE, extrathyroidal extension; CLNM, central lymph node metastasis; LLNM, lateral lymph node metastasis; TT, total thyroidectomy.