Abstract
From 1996 to 2000, the authors conducted a population-based case-control study among Connecticut women to test the hypothesis that genetic variation in xenobiotic metabolic pathway genes modifies the relation between hair dye use and risk of non-Hodgkin lymphoma. No effect modifications were found for women who started using hair dyes in 1980 or afterward. For women who started using hair dye before 1980 as compared with never users, a statistically significantly increased risk of non-Hodgkin lymphoma was found for carriers of CYP2C9 Ex3-52C>T TT/CT genotypes (odds ratio (OR) = 2.9, 95% confidence interval (CI): 1.4, 6.1), CYP2E1 -332T>A AT/AA genotypes (OR = 2.0, 95% CI: 1.2, 3.4), a homozygous or heterozygous 3-base-pair deletion in intron 6 of GSTM3 (OR = 2.3, 95% CI: 1.3, 4.1), GSTP1 Ex5-24A>G AA genotypes (OR = 1.8, 95% CI: 1.1, 2.9), or NAT2 genotypes conferring intermediate/rapid acetylator status (OR = 1.6, 95% CI: 1.0, 2.7). The observed associations were mainly seen for follicular lymphoma. In contrast, no significantly increased risk was observed for starting hair dye use before 1980 (relative to never use) among women who were homozygous wild-type for the CYP2C9, CYP2E1, or GSTM3 polymorphisms, women carrying 1 or 2 copies of the variant GSTP1 allele, or women who were slow NAT2 acetylators. A possible role of genetic variation in xenobiotic metabolism in the carcinogenicity of hair dye use needs to be confirmed in larger studies.