Table 5.

Fluorescence in situ hybridisation studies comparing primary breast cancers and their matched distant metastases

Reference	n	Discordance between metastases and primary tumours (percentage)	Number of HER2-positive primary tumours	Number of HER2-positive metastases
[23]	12	0	12	12
[20]	68	7.0	2	3
[22]	14	0	14	14
[21]	18	22.2	3	7
[19]	17	6.0	Not available	Not available
This study	105	7.6	21	20

HER2, gene encoding human EGF-like receptor 2.