Table 3.

Univariate overall survival analysis (N=28, # events=26, 7% censored).

	N	Deaths	HR (95% CI)	P-Value
Age at ATC diagnosis (years)	28		1.064 (1.014 - 1.116)	0.011
Stage				0.18
IVA	2	1 (50.0%)	Reference
IVB	20	19 (95.0%)	3.771 (0.499 - 28.468)
IVC	5	5 (100.0%)	7.246 (0.804 - 65.269)
Receipt of EBRT				0.002
No EBRT	7	7 (100.0%)	Reference
EBRT	21	19 (90.5%)	0.133 (0.038 - 0.463)
Total locoregional radiation dose (cGy)				0.32
< 4,000	11	9 (81.8%)	Reference
≥ 4,000	6	6 (100.0%)	1.799 (0.568 - 5.700)
Radiation fractionation (fractions/day)				0.12
1	8	7 (87.5%)	Reference
2	9	8 (88.9%)	0.427 (0.147 - 1.235)
Receipt of surgery				0.036
No surgery	8	8 (100.0%)	Reference
Surgery	20	18 (90.0%)	0.384 (0.157 - 0.938)
Receipt of chemotherapy				0.21
No chemotherapy	14	13 (92.9%)	Reference
Chemotherapy	14	13 (92.9%)	0.605 (0.276 - 1.323)
Initial or concomitant diagnosis of differentiated thyroid cancer (papillary or follicular)				0.31
No	22	21 (95.5%)	Reference
Yes	6	5 (83.3%)	0.602 (0.224 - 1.617)
Lymphovascular invasion				0.76
No	5	5 (100.0%)	Reference
Yes	14	12 (85.7%)	0.846 (0.287 - 2.491)
Extrathyroidal extension				0.21
No	4	3 (75.0%)	Reference
Yes	23	22 (95.7%)	2.182 (0.649 - 7.340)
Leukocytosis				0.12
No	12	11 (91.7%)	Reference
Yes	12	11 (91.7%)	1.994 (0.833 - 4.773)

Patients with unknown values for a covariate were excluded from the respective univariate analysis.

Counts and row percentages of deaths are presented for all covariates except for age.

Hazard ratios and confidence intervals are from Cox proportional hazards models, with p-values calculated by Wald chi-square tests.

HR = hazard ratio; CI = confidence interval; EBRT = external beam radiation therapy.