Better Postdiagnosis Diet Quality Is Associated with Reduced Risk of Death among Postmenopausal Women with Invasive Breast Cancer in the Women's Health Initiative

Stephanie M. George; Rachel Ballard-Barbash; James M. Shikany; Bette J. Caan; Jo L. Freudenheim; Candyce H. Kroenke; Mara Z. Vitolins; Shirley A. Beresford; Marian L. Neuhouser

doi:10.1158/1055-9965.EPI-13-1162

DOI: 10.1158/1055-9965.EPI-13-1162 Published April 2014

Article Figures & Data

Tables

Table 1.

Demographic, clinical, and lifestyle characteristics of 2,317 women with invasive breast cancer in the WHI by HEI-2005 quartiles

	Poor-quality diets		Mixed-quality diets				Better-quality diets
	Healthy Eating Index-2005 Score Quartile 1 (34–63)		Healthy Eating Index-2005 Score Quartile 2 (63–71)		Healthy Eating Index-2005 Score Quartile 3 (71–77)		Healthy Eating Index-2005 Score Quartile 4 (77–91)
	N	(%)	N	(%)	N	(%)	N	(%)	P^a
Number of participants	579		579		580		579
Age at screening for WHI
Mean (SE)	63.6 (0.3)		63.6 (0.3)		63.4 (0.3)		63.9 (0.3)		0.639
Years since diagnosis
Mean (SE)	1.6 (0.4)		1.5 (0.05)		1.4 (0.04)		1.6 (0.04)		0.366
Calories (kcals/day)
Mean (SE)	1665 (27.1)		1558.7 (23.7)		1454.4 (21.0)		1470.2 (19.8)		<0.0001
Alcohol servings/wk
Mean (SE)	3.3 (0.3)		2.6 (0.2)		1.7 (0.1)		1.0 (0.1)		<0.0001
MET-hours/week of MVPA^b
Mean (SE)	8.1 (0.5)		9.9 (0.5)		10.6 (0.5)		13.3 (0.7)		<0.0001
BMI^c
Mean (SE)	29.3 (0.3)		28.6 (0.2)		27.8 (0.2)		27.0 (0.2)		<0.0001
Race/ethnicity									0.773
White	510	88	505	87	516	89	522	90
Black	41	7	38	7	28	5	24	4
Hispanic	12	2	16	3	13	2	13	2
Other	15	3	20	3	20	3	19	3
Unknown	1	0	1	0	2	0	1	0
Education									0.002
High school or less	121	21	94	16	86	15	86	15
Some college	236	41	214	37	221	38	189	33
College	65	11	75	13	79	14	77	13
Postgraduate	152	26	190	33	189	33	225	39
Missing	5	1	6	2	5	1	2	0
Income									0.029
≥$50,000	199	34	228	39	250	43	249	43
$20,000–49,999	259	45	257	44	237	41	238	41
<$20,000	81	14	69	12	66	11	56	10
Missing	40	7	25	4	27	5	36	6
WHI component/arm									<0.0001
WHI Observational Study	264	46	247	43	278	48	323	56
WHI-DM-control	253	44	222	38	151	26	114	20
WHI-DM-intervention	62	11	111	19	150	26	142	25
Stage									0.974
Localized	436	75	427	74	436	75	443	77
Regional	132	23	142	25	136	23	128	22
Distant	6	1	4	1	3	1	3	1
Unknown	5	1	6	1	5	1	5	1
Estrogen receptor status									0.197
Positive	429	74	455	79	451	78	423	73
Negative	90	16	65	11	72	12	90	15
Unknown	60	10	59	10	57	10	66	11
Progesterone receptor status									0.751
Positive	358	62	357	62	371	64	349	60
Negative	153	26	153	26	135	23	150	26
Unknown	68	12	69	12	74	13	80	14
Postmenopausal hormone therapy									0.122
Never	213	37	195	37	192	33	189	33
Past	86	15	91	17	71	12	69	12
Current	280	48	293	51	317	55	321	55

↵^aP for χ² test for categorical variables or trend test for continuous variables.
↵^bFor 2,149 of 2,317 participants with known MVPA.
↵^cFor 2,297 of 2,317 participants with known measured BMI.

Table 2.

Postdiagnosis diet quality, risk of death from any cause, and risk of death from breast cancer among 2,317 postmenopausal women diagnosed with invasive breast cancer in the WHI

	Poor-quality diet	Mixed-quality diet		Better-quality diet
	Healthy Eating Index-2005 Score Quartile 1 (34–63)	Healthy Eating Index-2005 Score Quartile 2 (63–71)	Healthy Eating Index-2005 Score Quartile 3 (71–77)	Healthy Eating Index-2005 Score Quartile 4 (77–91)	P_trend
N	579	579	580	579
Death from any cause (n)	117	105	102	91
Unadjusted HR (95% CI)	1.00	0.84 (0.65–1.09)	0.79 (0.61–1.03)	0.67 (0.51–0.88)	0.004
Age and energy-adjusted HR (95% CI)	1.00	0.83 (0.64–1.08)	0.77 (0.59–1.01)	0.63 (0.48–0.83)	0.0009
Multivariate-adjusted HR (95% CI)^a	1.00	0.93 (0.71–1.22)	0.86 (0.65–1.14)	0.74 (0.55–0.99)	0.043
Death from breast cancer (n)	51	48	44	45
Unadjusted HR (95% CI)	1.00	0.89 (0.60–1.32)	0.79 (0.53–1.19)	0.78 (0.52–1.17)	0.178
Age and energy-adjusted HR (95% CI)	1.00	0.89 (0.60–1.32)	0.79 (0.53–1.19)	0.78 (0.52–1.16)	0.173
Multivariate-adjusted HR (95% CI)^a	1.00	0.99 (0.66–1.50)	0.93 (0.61–1.43)	0.91 (0.60–1.40)	0.627
Death from causes other than breast cancer (n)	66	57	58	46
Unadjusted HR (95% CI)	1.00	0.80 (0.56–1.14)	0.79 (0.56–1.13)	0.59 (0.40–0.86)	0.008
Age and energy-adjusted HR (95% CI)	1.00	0.79 (0.55–1.12)	0.77 (0.54–1.10)	0.52 (0.36–0.76)	0.001
Multivariate-adjusted HR (95% CI)^a	1.00	0.83 (0.58–1.20)	0.79 (0.54–1.15)	0.58 (0.38–0.87)	0.011

↵^aAdjusted for age at screening visit (continuous), WHI component (WHI-DM-intervention, WHI-DM-control, or OS), ethnicity (White non-Hispanic, Black/African American, Hispanic/Latino, other, missing), income (<20,000, 20,000–49,999, ≥50,000, missing), education (high school or below, some college, college, postgraduate, missing), stage (localized, regional, distant, unknown), estrogen receptor status (positive, negative, unknown), progesterone receptor status (positive, negative, unknown), time since diagnosis (continuous), energy intake in kcals (continuous), physical activity in MET-h/wk (0, 0.1–3, 3.1–8.9, 9+, unknown), servings of alcohol per week (continuous), and use of postmenopausal hormone therapy (never, former, current).

Table 3.

Multivariate associations between diet quality and death from any cause, stratified analysis by ER status

	Poor-quality diet	Mixed-quality diet		Better-quality diet
	Healthy Eating Index-2005 Score Quartile 1 (34–63)	Healthy Eating Index-2005 Score Quartile 2 (63–71)	Healthy Eating Index-2005 Score Quartile 3 (71–77)	Healthy Eating Index-2005 Score Quartile 4 (77–91)	P_trend	P_interaction
ER-positive
N	429	455	451	423
Death from any cause (n)	81	74	71	57
Multivariate-adjusted HR of all-cause mortality (95% CI)^a	1.00	0.82 (0.59–1.13)	0.71 (0.51–0.99)	0.55 (0.38–0.79)	0.0009
ER-negative						0.449
N	90	65	72	90
Death from any cause (n)	25	16	15	20
Multivariate-adjusted HR of all-cause mortality (95% CI)^a	1.00	0.90 (0.46–1.76)	0.92 (0.46–1.83)	1.14 (0.58–2.23)	0.811

NOTE: For 2,075 participants with known ER status.

↵^aAdjusted for age at screening visit (continuous), WHI component (WHI-DM-intervention, WHI-DM-control, or OS), ethnicity (White non-Hispanic, Black/African American, Hispanic/Latino, other, missing), income (<20,000, 20,000–49,999, ≥50,000, missing), education (high school or below, some college, college, postgraduate, missing), stage (localized, regional, distant, unknown), progesterone receptor status (positive, negative, unknown), time since diagnosis (continuous), energy intake in kcals (continuous), physical activity in MET-h/wk (0, 0.1–3, 3.1–8.9, 9+, unknown), servings of alcohol per week (continuous), and use of postmenopausal hormone therapy (never, former, current).