Table 2.

Metastatic breast cancer (MBC) case detection results by metastatic breast cancer status

	Recurrent MBC (stage 0–III at diagnosis)		de novo MBC (stage IV at diagnosis)		Non-MBC
	No.	%	No.	%	No.	%
Total	1302	100	495	100	7590	100
Age at diagnosis: mean (SD)	52.99 (13.04)		54.61 (13.62)		55.36 (12.99)
Year of breast cancer diagnosis
Before 2005	526	40.40	116	23.43	1738	22.90
2005–2009	463	35.56	189	38.18	2787	36.72
2010–2015	313	24.04	190	38.38	3065	40.38
Race
White	1025	78.73	394	79.60	5887	77.56
Black	51	3.92	25	5.05	229	3.02
Asian/Pacific Islander	206	15.82	70	14.14	1371	18.06
Other	4	0.31	2	0.40	57	0.75
Missing	16	1.23	4	0.81	46	0.61
Ethnicity
Hispanic	129	9.91	55	11.11	588	7.75
Non-Hispanic	1170	89.86	439	88.69	6968	91.81
Missing	3	0.23	1	0.20	34	0.45
Neighborhood socioeconomic statusa
Lowest quintile	45	3.46	40	8.08	342	4.51
Second quintile	121	9.29	64	12.93	631	8.31
Third quintile	215	16.51	81	16.36	988	13.02
Fourth quintile	254	19.51	105	21.21	1433	18.88
Highest quintile	646	49.62	195	39.39	4015	52.90
Missing	21	1.61	10	2.02	181	2.39
Stage
0	72	5.53	0	0.00	1813	23.87
I	302	23.20	0	0.00	2837	37.37
II	585	44.93	0	0.00	2186	28.80
III	307	23.58	0	0.00	616	8.10
IV	0	0.00	495	100.00	0	0.00
Missing	36	2.76	0	0.00	141	1.86
Tumor receptor subtypeb
Estrogen receptor and/or progesterone receptor (PR)-positive and HER2-negative	608	46.70	247	49.90	3514	46.30
HER2-positive	259	19.89	117	23.64	969	12.77
Triple-negative	223	17.13	63	12.73	689	9.08
Missing	212	16.28	68	13.74	2418	31.86
Grade
1	163	12.52	21	4.24	1511	19.91
2	446	34.26	167	33.74	3020	39.79
3	580	44.55	177	35.76	2400	31.62
Missing	113	8.68	130	26.26	659	8.68
Histology
Ductal	1146	88.02	413	83.43	6433	84.76
Lobular	117	8.99	56	11.31	703	9.26
Other	39	3.00	26	5.25	454	5.98
Marital status
Single	202	15.52	95	19.19	1133	14.93
Married	865	66.44	289	58.38	5096	67.14
Divorced	120	9.22	47	9.49	602	7.93
Widowed	81	6.22	44	8.89	518	6.82
Separated, unmarried, or domestic partner	20	1.54	15	3.03	170	2.24
Missing	14	1.07	5	1.01	71	0.94
Payer
Not insured	11	0.84	3	0.61	35	0.46
Insurance, not otherwise specified	144	11.06	45	9.09	729	9.60
Managed care/HMO/PPO	695	53.38	241	48.69	4489	59.14
Medicaid	121	9.29	60	12.12	390	5.14
Medicare	267	20.51	118	23.84	1610	21.21
Others	21	1.61	11	2.22	115	1.52
Missing	43	3.30	17	3.43	222	2.92

^aNeighborhood socioeconomic status (SES) quintile was assigned based on a previously developed measurement by Yost et al for cases diagnosed from 2000 to 2005, and Shariff-Marco et al for cases diagnosed 2006 to 2015.^30,31

^bTriple negative: estrogen receptor, progesterone receptor and HER2 all negative. HER2 positive: HER2 positive, regardless of estrogen receptor or progesterone receptor status.