XPC Lys939Gln polymorphism, smoking and risk of sporadic colorectal cancer among Malaysians

Table 1 Demographic characteristics of the study population n (%)

Variable	Cases (n = 255 )	Controls (n = 255)	P-value
Gender
Male	139 (54.5)	115 (45.1)	0.0341
Female	116 (45.5)	140 (54.9)
Mean age (yr)	53.17 ± 7.07	46.47 ± 12.02	0.086
Cigarette smoking
Yes	110	48	< 0.0011
No	145	207

¹Statistically significant.

Table 2 Genotype and allele frequencies of the xeroderma pigmentosum group CLys939Gln polymorphism in study subjects n (%)

	Cases (n = 255)	Controls (n = 255)	P-value
Genotype
Homozygous wildtype (AA)	108 (42.4)	129 (50.6)	0.062
Heterozygous (AC)	106 (41.6)	100 (39.2)	0.588
Homozygous variant (CC)	41 (16.0)	26 (10.2)	0.0491
Allele
A	322 (63.1)	358 (70.0)	0.294
C	188 (36.9)	152 (30.0)

¹Statistically significant.

Table 3 Xeroderma pigmentosum group C Lys939Gln polymorphism, smoking and colorectal cancer susceptibility risk

	Cases	Controls	OR (95%CI)	P-value
Genotype
Lys/Lys (AA)	108	129	1 (Reference)1
Lys/Gln (AC)	106	100	1.266 (0.871–1.841)	0.216
Gln/Gln (CC)	41	26	1.884 (1.082–3.277)	0.0252
Allele
A	322	358	1 (Reference)1	-
C	188	152	1.375 (1.050–1.802)	0.0202
Non-smoker
AA	64	104	1 (Reference)1
AC	64	81	1.284 (0.817–2.018)	0.278
CC	17	22	1.256 (0.620–2.542)	0.526
Smoker
AA	44	25	1 (Reference)1
AC	42	19	1.256 (0.605–2.609)	0.541
CC	24	4	3.409 (1.061–10.949)	0.0322

¹Homozygous wildtype genotype served as the reference category;

²Statistically significant.