Table 1.

Baseline characteristics.

Characteristics	Total (n = 16,513)	Unmarried group (n = 8949)	Married group (n = 7564)	p
Age (yr), median (IQR)	61.0 (52.0–71.0)	63.0 (53.0–75.0)	59.0 (50.0–68.0)	< 0.001
Race, n%				< 0.001
White	12,407 (75.13)	6346 (70.91)	6061 (80.13)
Black	2764 (16.74)	2001 (22.36)	763 (10.09)
Other	1296 (7.85)	576 (6.44)	720 (9.52)
Unknown	46 (0.28)	26 (0.29)	20 (0.26)
Grade, n%				0.234
I	1170 (7.09)	631 (7.05)	539 (7.13)
II	6017 (36.44)	3245 (36.26)	2772 (36.65)
III	6755 (40.91)	3626 (40.52)	3129 (41.37)
IV	99 (0.60)	54 (0.60)	45 (0.59)
Unknown	2472 (14.97)	1393 (15.57)	1079 (14.26)
Tumor subtype, n%				< 0.001
HR(–) & HER2(–)	2018 (12.22)	1115 (12.46)	903 (11.94)
HR(–) & HER2( +)	1306 (7.91)	677 (7.57)	629 (8.32)
HR( +) & HER2(–)	9201 (55.72)	4958 (55.40)	4243 (56.09)
HR( +) & HER2( +)	2489 (15.07)	1311 (14.65)	1178 (15.57)
Unknown	1499 (9.08)	888 (9.92)	611 (8.08)
Chemotherapy, n%				< 0.001
No	7465 (45.21)	4489 (50.16)	2976 (39.34)
Yes	9048 (54.79)	4460 (49.84)	4588 (60.66)
Radiation, n%				< 0.001
No	10,937 (66.23)	6052 (67.63)	4885 (64.58)
Yes	5207 (31.53)	2695 (30.12)	2512 (33.21)
Unknown	369 (2.23)	202 (2.26)	167 (2.21)
Surgery, n%				< 0.001
No surgery	10,951 (66.32)	6211 (69.40)	4740 (62.67)
Partial mastectomy	1554 (9.41)	750 (8.38)	804 (10.63)
Simple mastectomy	1308 (7.92)	645 (7.21)	663 (8.77)
Radical mastectomy	2542 (15.39)	1260 (14.08)	1282 (16.95)
Unknown	158 (0.96)	83 (0.93)	75 (0.99)
Distant organ metastasis, n%				< 0.001
No	1990 (12.05)	1000 (11.17)	990 (13.09)
One site	9374 (56.77)	5069 (56.64)	4305 (56.91)
Multiple site	4959 (30.03)	2773 (30.99)	2186 (28.90)
Unknown	190 (1.15)	107 (1.20)	83 (1.10)

Distant organ metastasis only included liver, brain, bone, and lung metastases in the SEER database (2010–2015).