Severe tinnitus and migraine headache in a 37-year-old woman treated with trastuzumab for breast cancer: A case report

BACKGROUND: Trastuzumab is a generally safe agent prescribed in the systemic treatment of breast cancer. Tinnitus is not a currently known adverse event related to trastuzumab. Here, we describe a rare case of severe tinnitus and a migraine headache induced by trastuzumab used for adjuvant therapy. CASE SUMMARY: A 37-year-old woman was diagnosed with hormone receptor-positive and human epidermal growth factor receptor 2-positive breast cancer. After surgery, she was treated with four cycles of epirubicin and cyclophosphamide; she then received docetaxel and a loading dose of trastuzumab plus pertuzumab. Less than half an hour after trastuzumab infusion, the patient complained of severe tinnitus and left-sided migraine headache. Trastuzumab monotherapy was discontinued immediately, and symptoms disappeared after 10 min. Trastuzumab was readministered, and severe tinnitus and migraine headache recurred. Trastuzumab was stopped, and severe tinnitus diminished after 10 min. Pertuzumab and docetaxel therapy was then administered, and no adverse events were observed. Subsequent infusions of trastuzumab every three weeks did not show the same symptoms. CONCLUSION: Although trastuzumab is well-tolerated in most patients, we should pay attention to the risk of severe tinnitus and migraine.