Table 1.

Breast cancer cases according to body mass index and other demographic and clinical characteristics; stages I, II, and III breast cancer patients from the POC-BP study (2004)

Patient characteristic	No.a (N = 5394)	Weighted %	BMI (kg/m2)
			Mean	SE	p valueb
BMI category (kg/m2)
< 18.5  18.5–24.9  25–29.9  30–34.9  ≥ 35	78 1614 1589 1120   960	1.5 32.5 30.3 19.8 15.8
Demographic characteristics  Age
20–40	398	6.3	27.9	0.4	< 0.001
40–49	1241	21.4	28.5	0.2
50–59	1427	26.7	29.2	0.2
60–69	1119	21.5	29.5	0.2
70–79	823	16.3	28.0	0.2
≥ 80	386	7.9	26.5	0.3
Race
White, non-Hispanic	3045	75.6	27.9	0.1	< 0.001
Black, non-Hispanic	1486	13.9	31.0	0.2
AI/AN, non-Hispanic	43	0.3	29.4	1.7
API, non-Hispanic	315	3.6	24.4	0.5
Hispanic	502	6.6	28.6	0.3
Insurance
Private	3238	62.9	27.9	0.1	< 0.001
Medicare/other public	1083	21.2	28.3	0.2
Medicaid	757	10.3	29.8	0.3
None	158	2.0	28.4	0.6
Unknown	158	3.7	28.7	0.5
Census-tract education
Higher	3286	69.2	27.8	0.1	< 0.001
Lower	2093	30.8	29.2	0.2
Census-tract poverty
Higher	4065	82.8	29.1	0.2	< 0.001
Lower	1314	17.2	28.1	0.1
Urbanicity
Urban	2773	52.5	28.0	0.1	0.01
Urban/rural mixed	1856	34.9	28.4	0.2
Rural	751	12.7	28.9	0.3
Registry (State)
1	600	17.2	28.7	0.2	< 0.001
2	490	9.2	28.2	0.3
3	577	11.2	28.5	0.3
4	321	9.2	27.7	0.3
5	983	8.7	29.2	0.3
6	1298	18.6	28.7	0.2
7	1125	25.9	27.5	0.2
Clinical characteristics  Tumor stage (AJCC)
I	2509	48.4	27.6	0.1	< 0.001
II	2067	37.6	28.5	0.2
III	818	14.0	29.4	0.2
Lymph nodes
Any positive	1920	33.9	28.9	0.2	< 0.001
All negative	3234	61.6	28.0	0.1
Unknown	240	4.5	27.2	0.4
Tumor size (cm)
≤ 0.5	451	8.8	27.7	0.3	< 0.001
0.51–1	847	16.2	27.3	0.2
1.01–2	1616	30.5	28.0	0.2
2.01–5	2011	37.1	28.6	0.2
> 5	410	6.3	29.5	0.4
Unknown	59	1.2	31.1	0.8
Histologic type
Ductal	3978	73.2	28.3	0.1	0.02
Lobular	373	7.3	28.4	0.3
Mixed ductal/lobular	348	7.3	27.1	0.3
Other	695	12.3	28.3	0.3
Grade
Well differentiated	943	19.0	27.6	0.2	0.07
Moderately differentiated	2051	39.0	28.2	0.2
Poorly differentiated	2036	35.8	28.5	0.2
Undifferentiated	62	1.0	28.6	0.9
Unknown/other	302	5.1	28.6	0.4
Hormone receptor status
ER+ and/or PR+	3846	73.0	28.4	0.1	0.13
ER– and PR–	1316	22.5	27.9	0.2
Unknown	232	4.5	27.7	0.4
HER2 receptor status
HER2+	1907	34.4	28.2	0.2	0.93
HER2–	2647	49.7	28.3	0.1
Unknown	840	15.9	28.3	0.2
Comorbidity
None	2420	45.5	26.4	0.1	< 0.001
Mild	2440	44.0	30.0	0.1
Moderate	373	7.4	29.3	0.3
Severe	161	3.1	28.9	0.5

AI/AN American Indian/Alaska Native, API Asian/Pacific Islander, ER+ estrogen receptor-positive, ER- estrogen receptor-negative, PR+ progesterone receptor-positive, PR- progesterone receptor-negative, HER2+ human epidermal growth factor 2 receptor-positive, HER2-human epidermal growth factor 2 receptor-negative

^aTotals may not add up to 5394 due to missing values for some variables

^bp values from general linear models comparing means between categories adjusted for age