Table 4.

Disease-specific survival in relationship to promoter Y/X single-nucleotide polymorphism genotypes and smoking^*

	No. of patients
Smoking level†	G/G	C/C + C/G	RR of death‡ (95% CI)	P§
White patients
<28.6 pack-years	82	51	0.94 (0.54 to 1.65)	.84
28.6–64.8 pack-years	159	104	0.70 (0.47 to 1.03)	.07
>64.8 pack-years	88	49	0.33 (0.17 to 0.61)	.001
African American patients
<28.6 pack-years	45	20	1.95 (0.94 to 4.05)	.07
28.6–64.8 pack-years	55	18	0.51 (0.22 to 1.18)	.11
>64.8 pack-years	24	7	0.92 (0.24 to 3.48)	.91

^*RR = risk ratio; CI = confidence interval.

^†Smoking levels were categorized by using the 25th and 75th percentile pack-year values of the white patient subjects (<25th percentile, 25th–75th percentile, and >75th percentile).

^‡Risk ratio of death of C/C (X/X) plus C/G (X/Y) versus G/G (Y/Y) genotypes was adjusted for sex, stage (III–IV/I–II), current smoking status, and age. A dominant model was assumed.

^§A multivariable Cox proportional hazards model was used. All statistical tests were two-sided.