NEW YORK (Reuters Health) - Breast cancer patients with brain metastases treated with stereotactic radiosurgery and trastuzumab emtansine may be at increased risk of brain edema, according to findings from a small case series.
In fact, Dr. Julie A. Carlson told Reuters Health by email, "Clinicians caring for patients undergoing treatment for HER2+ breast cancer should be aware of the potential interaction between trastuzumab emtansine and stereotactic radiosurgery in order to address potential edema-related neurologic symptoms in a timely fashion."
In a February 3rd online paper in Neuro-Oncology, Dr. Carlson of the University of Colorado Cancer Center, Denver and colleagues note that more than half of patients with HER2+ breast cancer may develop brain metastases requiring some form of radiation therapy. However, the potential interaction between targeted agents such as the newly approved trastuzumab emtansine and radiation is unknown.
An unexpected reaction was suggested when the researchers observed that four patients treated with stereotactic radiosurgery showed clinically significant increased brain edema as evinced by neurologic changes and MRI findings shortly after receiving trastuzumab emtansine infusion.
Symptoms included headaches, nausea and vomiting, speech impairment and short-term memory deficits. All were started on steroids and eventually showed clinical and radiological improvement. One of these patients underwent resection of a single posterior fossa metastasis. Pathology revealed severe radionecrosis apparently without viable tumor cells.
To help put these findings in perspective, the team examined data on all 13 patients with metastatic breast cancer and brain metastases who were treated with stereotactic radiosurgery at their institution during the two-year period in which these four had been treated. Three other patients also got trastuzumab emtansine but did not develop radiation necrosis. The overall proportion with clinically significant radiation necrosis was thus 57%.
Preclinical data shows that radiation upregulates HER2/neu gene expression in human breast cancer cell lines, say the investigators, which leads to a heightened response to trastuzumab; this might underlie the findings. There are also other mechanisms that could be involved.
"However," concluded Dr. Carlson, "our findings are purely observational and hypothesis generating; further clinical and laboratory investigation should be performed to better understand the nature of this interaction."
SOURCE: http://bit.ly/1n2Gy3J
Neuro-Oncology 2014.
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου