Table 4.

Univariate and multivariate disease-free survival Cox analyses in breast cancer patients with bone metastasis

Covariate	Univariate analysis			Multivariate analysis
	HR	95% CI	P-value	HR	95% CI	P-value
Clinical factors
Age (≤50 vs >50 years)	0.33	0.09–1.19	0.092	0.30	0.07–1.21	0.091
Menstrual status (post- vs pre-menopause)	3.59	0.79–16.22	0.096	4.00	0.86–18.50	0.076
Tumor size (≤5 vs >5 cm)	1.48	0.33–6.69	0.610	3.74	0.66–21.08	0.134
Lymph node status (negative vs positive)	1.66	0.51–5.39	0.398	1.31	0.39–4.36	0.658
Pharmacogenetic factors
ABCB1 3435C>T (CC vs CT+TT)	2.23	0.61–8.13	0.221	n/a	n/a	n/a
ABCC2 −24C>T (CT vs CC)	2.69	0.74–9.78	0.133	3.16	0.84–11.89	0.088
CYP3A5 6986A>G (AA+AG vs GG)	2.20	0.48–9.98	0.304	n/a	n/a	n/a
CYP2D6 100C>T (CC+CT vs TT)	1.51	0.47–4.92	0.489	n/a	n/a	n/a
Combined genotypes of ABCB1 and ABCC2
Other combined genotypes vs ABCC2 CC − ABCB1 CT+TT	2.95	0.99–8.80	0.051	3.70	1.06–12.89	0.040a,*

Notes:

^*Statistically significant at P-value <0.05;

^aP-value was calculated from the covariates which were all clinical factors and the combined genotypes of ABCB1 and ABCC2. Abbreviations: CI, confidence interval; HR, hazard ratio; n/a, not applicable.