Table 2.

Associations Between Use of Hair Dye and Risk of Non-Hodgkin Lymphoma According to Cytochrome P-450 Genotype Among Connecticut Women, 1996–2000

	CYP2C9 (rs1799853)								P Valuea	CYP2E1 (rs2070673)								P Valuea
	CC				CT + TT					TT				AT + AA
	No. of Cases	No. of Controls	ORb	95% CI	No. of Cases	No. of Controls	ORb	95% CI		No. of Cases	No. of Controls	ORb	95% CI	No. of Cases	No. of Controls	ORb	95% CI
Total
Never use	100	124	1.0	Referent	16	33	1.0	Referent		75	98	1.0	Referent	41	59	1.0	Referent
Ever use	258	287	1.1	0.8, 1.5	81	89	1.9	1.0, 3.8	0.154	220	255	1.1	0.8, 1.6	121	122	1.4	0.9, 2.3	0.434
Year of starting hair dye use (vs. never use)
Before 1980	166	170	1.2	0.9, 1.7	58	43	2.9	1.4, 6.1	0.033	143	148	1.3	0.9, 1.8	81	65	2.0	1.2, 3.4	0.245
1980 or later	92	117	0.9	0.6, 1.4	23	46	1.0	0.4, 2.3	0.889	77	107	1.0	0.6, 1.5	40	57	0.9	0.5, 1.7	0.808
Non-Hodgkin lymphoma subtype among women who started using hair dye before 1980 (vs. never use)
Diffuse large B-cell lymphoma	46	170	1.0	0.6, 1.6	15	43	2.0	0.7, 5.9	0.212	43	148	1.1	0.6, 1.9	18	65	1.2	0.5, 2.7	0.918
Follicular lymphoma	35	170	1.4	0.7, 2.6	20	43	6.3	1.6, 24.7	0.055	34	148	1.4	0.7, 2.8	21	65	3.9	1.4, 11.1	0.161
CLL/SLL	25	170	1.7	0.8, 3.5	6	43	4.6	0.5, 40.1	0.386	20	148	1.5	0.6, 3.4	11	65	3.2	0.9, 12.4	0.302

Abbreviations: CI, confidence interval; CLL/SLL, chronic lymphocytic leukemia/small lymphocytic leukemia; CYP, cytochrome P-450; OR, odds ratio.

^aP value for the interaction between a given hair dye exposure variable and genotype variations in a logistic regression model, with adjustment for age (continuous) and race (white vs. nonwhite).

^bLogistic regression model with adjustment for age (continuous) and race (white vs. nonwhite).