According to a report published in the Annals of Oncology, women with Herr-2 positive breast cancer who received trastuzumab as adjuvant therapy are at significantly increased risk of metastases in the central nervous system as a first recurrence of the tumor.
According to Dr. Erin Olson, a neurologist at Ohio State University and author of the study, trastuzumab significantly reduced the risk of recurrence, but clinicians should be aware that it increases the risk of them occur in the nervous system. Physicians should carefully monitor patients for neurologic symptoms.
It is suggested that the nervous system is the "refuge" for micro metastatic tumors because trastuzumab does not cross the blood-brain barrier or because tumor cells that do not overexpress Herr-2 receptor migrate more easily into the brain.
In previous studies, Dr. Olson and her team showed that anti Herr-2 targeted therapies increase the frequency of brain metastases. This spurred her to investigate the relationship between brain metastases and trastuzumab. The team analyzed four Phase III clinical trials with a total of 9,020 participants.
Since 4921 women receiving trastuzumab, 125 relapse in the breast (incidence of 2.56%). Of 4099 women who received trastuzumab, 78 relapse of the tumor in the brain (1.94%). In patients treated with trastuzumab treatment brain metastases / total metastases is 16.94 / 100, while those treated with other adjuvant is 8.33 / 100.