Her 2+ primary, her2 - mets: Herceptin/Lapatinib?

[Rich66]

Does her2+ status of operable primary influence treatment of her2 - mets? Just occurred to me that biopsies in a met situation are often from one site. How to know whether there are her2+ cells floating around that could be targeted? Intuitively, you might think it would be naive to assume there aren't. You can have different her2 status in two tumors in a multifocal primary setting based on surgical pathology. This would indicate Herceptin use. In a met situation, seems like pathology is often too limited to accurately assess things.

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