Fruit and vegetable intake and risk of breast cancer by hormone receptor status.
BACKGROUND
Estrogen receptor-negative (ER(-)) breast cancer has few known or modifiable risk factors. Because ER(-) tumors account for only 15% to 20% of breast cancers, large pooled analyses are necessary to evaluate precisely the suspected inverse association between fruit and vegetable intake and risk of ER(-) breast cancer.


METHODS
Among 993 466 women followed for 11 to 20 years in 20 cohort studies, we documented 19 869 estrogen receptor positive (ER(+)) and 4821 ER(-) breast cancers. We calculated study-specific multivariable relative risks (RRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression analyses and then combined them using a random-effects model. All statistical tests were two-sided.


RESULTS
Total fruit and vegetable intake was statistically significantly inversely associated with risk of ER(-) breast cancer but not with risk of breast cancer overall or of ER(+) tumors. The inverse association for ER(-) tumors was observed primarily for vegetable consumption. The pooled relative risks comparing the highest vs lowest quintile of total vegetable consumption were 0.82 (95% CI = 0.74 to 0.90) for ER(-) breast cancer and 1.04 (95% CI = 0.97 to 1.11) for ER(+) breast cancer (P (common-effects) by ER status < .001). Total fruit consumption was non-statistically significantly associated with risk of ER(-) breast cancer (pooled multivariable RR comparing the highest vs lowest quintile = 0.94, 95% CI = 0.85 to 1.04).


CONCLUSIONS
We observed no association between total fruit and vegetable intake and risk of overall breast cancer. However, vegetable consumption was inversely associated with risk of ER(-) breast cancer in our large pooled analyses.
Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Longwood Avenue, Boston, MA 02115, USA. pojun@channing.harvard.edu
Seungyoun
S
Jung
Donna
D
Spiegelman
Laura
L
Baglietto
Leslie
L
Bernstein
Deborah A
DA
Boggs
Piet A
PA
van den Brandt
Julie E
JE
Buring
James R
JR
Cerhan
Mia M
MM
Gaudet
Graham G
GG
Giles
Gary
G
Goodman
Niclas
N
Hakansson
Susan E
SE
Hankinson
Kathy
K
Helzlsouer
Pamela L
PL
Horn-Ross
Manami
M
Inoue
Vittorio
V
Krogh
Marie
M
Lof
Marjorie L
ML
McCullough
Anthony B
AB
Miller
Marian L
ML
Neuhouser
Julie R
JR
Palmer
Yikyung
Y
Park
Kim
K
Robien
Thomas E
TE
Rohan
Stephanie
S
Scarmo
Catherine
C
Schairer
Leo J
LJ
Schouten
James M
JM
Shikany
Sabina
S
Sieri
Schoichiro
S
Tsugane
Kala
K
Visvanathan
Elisabete
E
Weiderpass
Walter C
WC
Willett
Alicja
A
Wolk
Anne
A
Zeleniuch-Jacquotte
Shumin M
SM
Zhang
Xuehong
X
Zhang
Regina G
RG
Ziegler
Stephanie A
SA
Smith-Warner
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000737:chemistry* / Q000453:epidemiology / Q000517:prevention & control*; D002986:Clinical Trials as Topic; D005247:Feeding Behavior; D005260:Female; D005638:Fruit; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D011960:Receptors, Estrogen / Q000032:analysis*; D011980:Receptors, Progesterone / Q000032:analysis*; D012306:Risk; D011795:Surveys and Questionnaires; D014675:Vegetables
D014408:Biomarkers, Tumor; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone