Polymorphisms in thymidylate synthase gene and susceptibility to breast cancer in a Chinese population: a case-control analysis

Table 1 Comparison of breast cancer cases and controls by selective characteristics

Variable	Controls^c (n = 473)	Breast cancer (n = 432)	P value
Age, yr (mean ± SD)	51.42 ± 11.12	52.09 ± 11.03	0.36
Age at menarche, yr (mean ± SD)	16.40 ± 1.77	15.32 ± 1.92	<0.0001
Age at first live birth, yr (mean ± SD) ^a	24.49 ± 2.47	25.51 ± 3.45	<0.0001
Age at menopausal, yr (mean ± SD) ^b	49.79 ± 3.88	48.89 ± 4.26	0.02
BMI	23.69 ± 3.35	23.95 ± 3.55	0.25
Menopausal status			0.74
Premenopausal	210(44.4)	197(45.6)
Postmenopausal	263(55.6)	235(54.4)
Family History of Cancer			0.033
Positive	95(20.1)	113(26.2)
Negative	378(79.9)	319(73.8)
TSER			0.987
3R allele	753(79.6)	688(79.8)
2R allele	193(20.4)	176(20.2)
TS 3'-UTR del6			0.347
del6 allele	633(66.9)	596(69.0)
ins6 allele	313(33.1)	268(31.0)
Haplotypes of TSER and TS 3'-UTR del6 polymorphisms			0.863
3R-del6	295(62.4)	271(62.6)
3R-ins6	83(17.5)	73(17.0)
2R-del6	25(5.3)	28(6.4)
2R-ins6	70(14.8)	60(14.0)

^a Age at first live birth information was available in 460 controls and 419 breast cancer cases.
^b Age at menopausal information was available in 226 controls and 227 breast cancer cases with postmenopausal status.
^cThree controls carrying the rare alleles of more than three 28 bp repeats (>3R) were excluded in the current analyses.

ISSN: 1471-2407