Table 3.

Comparison of HER2 Ratio and Average HER2 Gene Copy Number and ASCO-CAP Groupings With Clinical Outcomes in BCIRG-005

HER2 FISH (HER2/CEP17) Ratio	HER2 Copies per Cell	No. of Subjects	DFS, No. of Events	OS, No. of Events	DFS HR (95% CI) and P for Log-Rank Test*	OS HR (95% CI) and P for Log-Rank Test*	ASCO-CAP FISH Group
< 2.0	< 4.0	3,079	971	606	1.0 (reference)	1.0 (reference)	Group 5
	4.01-6.0	176	51	30	0.923 (0.697 to 1.224)	0.878 (0.609 to 1.267)	Group 4
					P = .5795	P = .4872
	≥ 6	11	6	4	2.502 (1.121 to 5.583)	2.351 (0.879 to 6.284)	Group 3
					P = .0252	P = .0885

NOTE. The hazard ratios are for each ASCO group compared with ASCO Group 5 taken as the reference. There were too few patients accrued to BCIRG-005 with a HER2 FISH ratio ≥ 2.0 for analysis of DFS or OS.

Abbreviations: BCIRG, Breast Cancer International Research Group; CAP, College of American Pathologists; DFS, disease-free survival; HER2, human epidermal growth factor receptor 2; HR, hazard ratio; OS, overall survival.

^*Group 5 (reference) compared with each other group in BCIRG-005 (HER2 not amplified breast cancers).