Interaction between tumor stage and age on survival outcomes of patients with anaplastic thyroid cancer

Table 3 Multivariate cox proportional hazard regression analyses of factors affecting all-cause mortality and cancer related mortality among United States patients diagnosed with anaplastic thyroid cancer between 2010 and 2017

Characteristics	Overall mortality	Cancer related mortality
	Adjusted proportional, HR (95%CI)	Adjusted proportional, HR (95%CI)
Gender
Female	1 (Reference)	1 (Reference)
Male	1.11 (0.89-1.38)	1.09 (0.87-1.36)
Age at diagnosis, year old
00-59	1 (Reference)	1 (Reference)
60-79	2.85 (0.61-13.43)	2.16 (0.46-10.18)
80 +	2.01 (0.40-10.18)	1.48 (0.29-7.60)
Marital status
Married	1 (Reference)	1 (Reference)
Single	1.00 (0.75-1.34)	0.94 (0.69-1.26)
Divorced/separated	0.63 (0.42-0.94)a	0.61 (0.40-0.92)a
Widowed	1.03 (0.78-1.37)	1.03 (0.77-1.37)
Tumor stage
Localized	1 (Reference)	1 (Reference)
Regional by direct extension only	6.26 (1.29-30.42)a	5.05 (1.05-24.19)a
Regional lymph nodes involved only	2.71 (0.42-17.49)	2.30 (0.36-14.68)
Regional by both direct extension and lymph node involvement	3.58 (0.74-17.31)	2.97 (0.62-14.15)
Distant	5.73 (1.34-24.51)a	4.57 (1.08-19.29)a
Race
Non-Hispanic white	1 (Reference)	1 (Reference)
Non-Hispanic black	0.91 (0.62-1.35)	0.90 (0.60-1.34)
Hispanic	1.16 (0.90-1.51)	1.13 (0.87-1.49)
Other	1.14 (0.85-1.54)	1.12 (0.83-1.52)
Living area
Counties in metropolitan areas of 1 million persons	1 (Reference)	1 (Reference)
Counties in metropolitan areas of 250000 to 1 million persons	1.26 (0.99-1.60)	1.26 (0.99-1.61)
Counties in metropolitan areas of 250000 persons	0.76 (0.46-1.27)	0.82 (0.49-1.38)
Nonmetropolitan counties adjacent to a metropolitan area	0.79 (0.50-1.26)	0.80 (0.50-1.29)
Nonmetropolitan counties not adjacent to a metropolitan area	1.19 (0.70-2.01)	1.25 (0.74-2.13)
Income per year
$ < $45000	1 (Reference)	1 (Reference)
$45000-54999	0.75 (0.43-1.31)	0.72 (0.41-1.26)
$55000-64999	1.04 (0.59-1.82)	1.01 (0.57-1.77)
$65000-74999	0.85 (0.48-1.51)	0.84 (0.47-1.50)
$75000 +	0.74 (0.42-1.33)	0.71 (0.40-1.29)
Radiation
No	1 (Reference)	1 (Reference)
Yes	0.66 (0.53-0.83)b	0.64 (0.51-0.81)b
Chemotherapy
No	1 (Reference)	1 (Reference)
Yes	0.63 (0.50-0.79)b	0.62 (0.50-0.78)b
Surgery
No	1 (Reference)	1 (Reference)
Yes	0.53 (0.43-0.66)b	0.51 (0.41-0.63)b

^aP < 0.05.

^bP < 0.01.

HR: Hazard ratio.