BRCA2mutation carriers, reproductive factors and breast cancer risk

Breast Cancer Research

Table 2 Parous women: multivariate analysis of the effects of risk factors for BRCA2-positive cases and BRCA2-negative cases separately

	BRCA2-positive cases (n = 100) versus matched controls (n = 1000)		BRCA2-negative cases (n versus = 361) matched controls (n = 1000)
Risk factor	Odds ratio (95% confidence interval)	P value	Odds ratio (95% confidence interval)	P value
Age at menarche	0.92 (0.74–1.14)	0.430	0.87 (0.77–0.99)	0.030
Age at first birth	1.01 (0.93–1.10)	0.738	1.02 (0.97–1.07)	0.352
Number of births	1.17 (0.95–1.43)*	0.132	0.87 (0.75–1.00)*	0.057
Total duration of breast-feeding (unit, 6 months)	0.96 (0.91–1.01)**	0.141	1.01 (0.98–1.03)**	0.579

Odds ratios are presented per unit increment of the variables. * P = 0.007, odds ratio = 1.49 for the interaction between the number of births and the mutation status. ** P = 0.045, odds ratio = 0.93 for the interaction between the total duration of breast feeding and the mutation status. When testing for interaction between the other variables and the mutation status, P > 0.4.

ISSN: 1465-542X