ototoxicity after high-dose chemotherapy with cyclophosphamide, thiotepa and carboplatin followed by stem cell transplantation in patients with breast cancer

Our purpose was to determine the risk of ototoxicity in breast cancer patients receiving a myeloablative regimen consisting of cyclophosphamide 6000 mg/m², thiotepa 500mg/m² and carboplatin 800mg/m² (CTCb) followed by stem cell transplantation. Fourteen consecutive patients with breast cancer were treated with high dose chemotherapy consisting of the CTCb regimen followed by stem cell transplantation. A pretransplant complete hearing study was obtained which consisted of hearing case history, audiometry and tympanometry. In addition, DPOAE (Distortion Product Otoaccoustic Emissions) was done to evaluate measurable changes in the cochlear (outer hair cell) functioning. Pre-transplant, all patients had no clinical evidence of hearing impairment and hearing studies were normal. Eleven patients had hearing studies and a telephone interview posttransplant. One patient was lost to follow-up and two patients died. One of the 11 patients tested had an abnormal post-transplant hearing study but none of them had clinically detectable hearing impairment. In our prospective study of breast cancer patients treated with the CTCb regimen, we did not observe clinically detectable hearing impairment in any of the patients tested.