Table 4.

Potential prognostic factors affecting PFS with trastuzumab

	Unadjusted HR (95% CI)a)	p-valueb)	Adjusted HR (95% CI)	p-valuec)
p95HER2 expression	0.85 (0.44-1.60)	0.628	1.01 (0.45-2.20)	0.975
PTEN deletion/down-regulation	0.84 (0.53-1.30)	0.456	1.30 (0.60-3.00)	0.488
PIK3CA mutation	1.20 (0.75-1.90)	0.476	1.20 (0.50-2.70)	0.649
Ethnic group: Malayd)	2.90 (0.70-12.70)	0.149	3.70 (0.70-19.80)	0.121
Ethnic group: Koreand)	2.10 (1.30-3.50)	0.004	2.00 (0.99-4.10)	0.051
Contralateral breast	0.37 (0.14-0.99)	0.047	0.30 (0.08-1.10)	0.078

PFS, progression-free survival; HR, hazard ratio; CI, confidence interval; p95HER2, truncated human epidermal growth factor receptor 2; PTEN, phosphatase and tensin homolog; PIK3CA, phosphatidylinositol 3 kinase (catalytic subunit).

^a)Univariate analysis,

^b)Log-rank test of survival distribution equality for subgroups defined by positive and negative biomarker status,

^c)From Cox proportional hazards model adjusted for prognostic factors that are found to be significantly related to PFS on lapatinib in the univariable analysis for primary endpoint and 3 biomarkers (p95HER2 protein expression, PTEN deletion/downregulation, and PIK3CA mutation),

^d)Reference group: Chinese.