Table 2.

Conversion rates of receptor status between primary tumor and metastasis at local and central laboratories

At local laboratory	Overall		HR positive		HER2 amplified		Triple negative
	n	%	n	%	n	%	n	%
ER, n = 160
No conversion	126	79	94	82	18	60	14	93
From positive to negative	14	9	7	6	6	20	1	7
From negative to positive	20	12	14	12	6	20	0	0
Fisher’s exact test	p = 0.032
PR, n = 156
No conversion	102	65	66	59	21	72	15	100
From positive to negative	34	22	28	25	6	21	0	0
From negative to positive	20	13	18	16	2	7	0	0
Fisher’s exact test	p = 0.021
HER2, n = 140
No conversion	117	84	78	80	26	93	13	93
From positive to negative	9	6	8	8	0	0	1	7
From negative to positive	14	10	12	12	2	7	0	0
Fisher’s exact test	p = 0.322
At central laboratoy ER, n = 167
No conversion	146	87	108	92	22	71	16	89
From positive to negative	16	10	10	8	6	19	0	0
From negative to positive	5	3	0	0	3	10	2	11
Fisher’s exact test	p < 0.05
PR, n = 167
No conversion	120	72	86	73	18	58	16	89
From positive to negative	34	20	24	20	10	32	0	0
From negative to positive	13	8	8	7	3	10	2	11
Fisher’s exact test	p = 0.042
HER2, n = 165
No conversion	160	97	113	97	31	100	16	94
From positive to negative	0	0	0	0	0	0	0	0
From negative to positive	5	3	4	3	0	0	1	6
Fisher’s exact test	p = 0.443

ER estrogen receptor, HER2 human epidermal growth factor receptor 2, HR hormone receptor, PR progesterone receptor