Dietary intake of Cruciferous vegetables, Glutathione S-transferase (GST) polymorphisms and lung cancer risk in a Caucasian population

Cancer Causes and Control 15: 977985, 2004. 977

2004 Kluwer Academic Publishers. Printed in the Netherlands.Dietary intake of Cruciferous vegetables, Glutathione S-transferase (GST)

polymorphisms and lung cancer risk in a Caucasian populationLisa I. Wang1, Edward L. Giovannucci1,2, David Hunter1,2, Donna Neuberg1,2,Li Su1 & David C. Christiani1,3,*

1Departments of Epidemiology, Environmental Health, Occupational Health Program, Nutrition and Biostatistics

Harvard School of Public Health, Boston, MA 02115, USA;2Department of Medicine, Brigham and Womens

Hospital, Harvard Medical School, Boston, MA 02115, USA;3Pulmonary and Critical Care Unit, Department ofMedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USAReceived 18 November 2003; accepted in revised form 1 July 2004Key words: cruciferous vegetables, GSTM1, GSTT1, lung cancer, gene-environment interaction.Abbreviations: BAP, benzo(a)pyrene; CI, condence interval; CYP450, cytochrome P450; GST, Glutathione

s-transferase; ITC, isothiocyanate; OR, odds ratio.AbstractObjective: To evaluate possible interactions between dietary intake of cruciferous vegetables and the glutathione

s-transferase mu and theta (GSTM1 and GSTT1) genotypes in lung cancer risk.Methods: Hospital-based casecontrol study of 716 Caucasian lung cancer cases and 939 spouse and friend controls

conducted in Boston, Massachussetts between 1992 and 2000. Dietary intake was collected through a food

frequency questionnaire and blood was obtained for genotyping. Logistic regression models were adjusted for age,

gender, total calories and smoking variables.Results: Higher intakes of cruciferous vegetables reduced lung cancer risk among GSTM1 present individuals (odds

ratio (OR)highest versus lowest tertile 0.61, 95% condence interval (CI) 0.390.95) but not among GSTM1 null

individuals (ORhighest versus lowest tertile 1.15, 95% CI 0.781.68). We observed statistically signicant interactions between GSTM1 and cruciferous vegetable intake overall (likelihood ratio test (LRT): p 0.05) and among

current smokers (LRT: p 0.01). No signicant interactions were observed for GSTT1 or the combined GSTM1/T1

genotype.Conclusions: In our study, higher cruciferous vegetable intake reduced lung cancer risk only among individuals with

the GSTM1 present genotype. Our ndings diered from prior studies that specically assessed isothiocyanates

found in cruciferous vegetables or evaluated Asian study populations with higher levels of cruciferous vegetable

consumption.IntroductionCruciferous vegetables, particularly those in the brassica

genus (e.g., broccoli, cabbage, kale, mustard greens,

Brussels sprouts, cauliower) have been frequently

associated with lower risk of lung, stomach, colon and

rectal cancer [1]. They have high levels of glucosinolates,

which are hydrolyzed to products such as isothiocyanates (ITC) by myrosinase,...