Table 1.

ER-Negative to ER-Positive HRs Over Time

Years After Dx	ER-Negative HRs	ER-Positive HRs	HR
0	1.9	1.3	1.4
2	6.2	1.8	3.5
4	4.1	2.0	2.0
6	2.4	1.7	1.4
8	1.3	1.5	0.9
10	0.8	1.4	0.6
12	0.7	1.4	0.5

NOTE. As described in Figure 1A, the ER-negative to ER-positive HRs varied (ie, were nonproportional) over time. For example, HRs were more than 1.0 before the eighth year after initial breast cancer, after which HRs were less than 1.0.

Abbreviations: ER, estrogen receptor; dx, diagnosis; HR, hazard ratio.