The authors concluded that there’s no reason to retest metastases. For me, that would depend on the patient. If I had a patient with a HER2-negative primary tumor who had exhausted all avenues of treatment and wanted to try trastuzumab, I would try to biopsy a metastatic lesion to determine if it was positive because the tumor might respond to trastuzumab. Even if it were a 10 percent chance, I would take it in an individual patient who was motivated and was not responding to other therapies. Trastuzumab has relatively low toxicity and, in some cases, it has shown significant benefit.
Ann D Thor, MD
In our experience, it is highly unusual for the HER2 status to be altered during the development of the cancer. It is also very rare for us to find disagreement between the HER2 status of the invasive disease and the carcinoma in situ in the same patient. This is also true when we compare the primary tumor to the lymph-node metastasis.
In general, the HER2 status is quite similar or the same with only rare exceptions. In some of those exceptions, the morphologic appearance of the metastasis appears to be different, as if the tumor either developed new characteristics or was developed from an independent primary tumor.
Michael F Press, MD, PhD |
