Breast cancer risk in premenopausal women is inversely associated with consumption of broccoli, a source of isothiocyanates, but is not modified by GST genotype.
The role of vegetable consumption in relation to breast cancer risk is controversial. Anticarcinogenic compounds may be present only in specific vegetables, thereby attenuating findings for total vegetable intake. Cruciferous vegetables contain precursors of isothiocyanates (ITCs), which may be chemopreventive through potent inhibition of phase I, and induction of phase II enzymes, such as glutathione S-transferases (GSTs). We investigated associations between consumption of cruciferous vegetables, sources of ITCs, and breast cancer risk, and potential modification of relations by GSTM1 and GSTT1 genotypes. Cases (n = 740) were Caucasian women with incident breast cancer identified from all major hospitals in Erie and Niagara counties. Community controls (n = 810) were frequency matched to cases by age and county. An in-depth interview including a validated FFQ was administered in person. Odds ratios (ORs) and 95% CIs were used to estimate relative risks. Consumption of cruciferous vegetables, particularly broccoli, was marginally inversely associated with breast cancer risk in premenopausal women [4th quartile OR = 0.6, 95% CI (0.40-1.01), P = 0.058]. Associations were weaker or null among postmenopausal women. No significant effects of GST genotype on risk were observed in either menopausal group. These data indicate that cruciferous vegetables may play an important role in decreasing the risk of premenopausal breast cancer.
Ambrosone
Christine B
CB
Division of Cancer Prevention and Population Science, Roswell Park Cancer Institute, Buffalo, NY, USA. christine.ambrose@roswellpark.org
McCann
Susan E
SE
Freudenheim
Jo L
JL
Marshall
James R
JR
Zhang
Yueshang
Y
Shields
Peter G
PG
D001937:Brassica / Q000737:chemistry; D001943:Breast Neoplasms / Q000209:etiology* / Q000235:genetics*; D004032:Diet; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D017879:Isothiocyanates / Q000032:analysis; D008875:Middle Aged; D017697:Premenopause; D012307:Risk Factors
D005982:Glutathione Transferase; D017879:Isothiocyanates; C413545:glutathione S-transferase T1