Incidence and course of ototoxic hearing loss in a big European cohort of childhood cancer patients - subproject of PanCareLIFE

Background: Ototoxicity is a common side effect after platin chemotherapy and existing studies are limited due to small cohorts and a variety of confounding factors (Grewal et al. , Langer et al. ). Therefore, studies that enrolled greater numbers of patients will help us to learn more about incidence and course of ototoxic hearing loss, clinical and genetic risk factors.Material and Methods: In the PanCare LIFE Project, data were collected about chemotherapy, radiation, other ototoxic medicaments and audiological follow-up from a number of European centers to create a cohort of childhood cancer patients who were treated with platin chemotherapy. The audiological tests of 2525 patients were evaluated by the Clinic for Phoniatrics and Pedaudiology at the University Hospital Münster as an audiological reference center and the hearing loss severity was classified according to the Muenster and the SIOP schemes (Schmidt et al. , Brock et al. ). The hearing loss course of all patients with sufficient audiological tests was analyzed by two pedaudiologists separately. Patients were assigned to the following phenotype groups: no hearing impairment (0 (Muenster classification) after 2nd/before 3rd cycle); hearing loss >=2b (Muenster classification) on at least one ear at end of chemotherapy; progression of hearing impairment after end of chemotherapy.Results: Phenotyping was possible in 513 patients. In total, 234 patients had no hearing loss during the whole observation period. During therapy, 263 patients suffered from a progressive hearing loss. Of these, 83 had an early onset hearing loss and 182 developed a hearing loss >=2b (Muenster classification) at the post-treatment evaluation. A progression of hearing loss later than 15 months after the end of therapy could be observed in 52 cases. Odds ratios between early onset hearing loss, severe hearing loss at the end of chemotherapy and posttherapeutic progression will be presented with detailed information on extent, rate and time course of hearing loss progression.Discussion: These data are the first preliminary results from a big European cohort of childhood cancer patients treated with platin chemotherapy, providing information about incidence and course of hearing loss in one of the biggest studies existing up to now. The predefined audiological phenotypes are discussed on the basis of different degrees and time courses of hearing loss progression