Ototoxic Effects Induced by Doxorubicin, Cyclophosphamide, and Paclitaxel in Oncological Breast Cancer Treatment Protocols

Abstract

Introduction: Ototoxicity is a common complication associated with chemotherapy for breast cancer, with potential to impair auditory function and negatively affect patients’ quality of life. Distortion product otoacoustic emissions (DPOAE) represent a sensitive and objective method for the early detection of alterations in outer hair cell activity, even in the absence of audiometric changes. Objective: To investigate the effects of the AC-T protocol (doxorubicin, cyclophosphamide, and paclitaxel) on the function of outer hair cells in the cochlea of patients with breast cancer. Method: A prospective, analytical, and observational cohort study. Meatoscopy and DPOAE recordings were performed at two time points: one week after the first day of the chemotherapy cycle and at the end of treatment. Statistical analysis was conducted using SPSS software version 20.0, with a significance level of 5% (p ≤ 0.05). Results: The sample consisted of women with a mean age of 52.36 years (±4.78). After treatment, 78.6% reported difficulty understanding speech in noisy environments, and 35.7% reported tinnitus. DPOAE showed a statistically significant reduction in response amplitude specifically at the 5 kHz frequency, indicating functional impairment of the outer hair cells. Conclusion: The AC-T protocol demonstrated ototoxic potential, with functional impairment of cochlear outer hair cells, particularly at 5 kHz. The presence of tinnitus and the high prevalence of speech-in-noise comprehension difficulties highlight the need for audiological monitoring in patients undergoing chemotherapy. The implementation of systematic auditory monitoring programs may enable early detection of hearing changes and support timely interventions.