Long-term MOGCT survivors treated with CBCT have small but significant reductions in age-adjusted hearing thresholds at 4, 6 and 8kHz versus Controls. Approximately one in four women experienced subjective hearing loss. To avoid overestimation of clinically relevant cisplatin-induced ototoxicity, absolute hearing thresholds should be age-adjusted and compared to an age-matched control group.

ObjectivesCisplatin‐related hearing loss (HL) is claimed to progress after treatment. This controlled longitudinal study with extended follow‐up investigates HL in testicular cancer survivors (TCSs) after cisplatin‐based chemotherapy (CBCT).Study DesignControlled longitudinal study.MethodsEighty‐two TCSs treated with CBCT between 1980 and 1994 in Norway participated in two surveys (S1/S3), including pure‐tone audiograms (0.125–8 kHz) and self‐reported HL, 12 and 31 years after treatment, respectively. Hearing thresholds were age‐adjusted based on age‐matched hearing thresholds from the general population (controls). Hearing loss was defined as thresholds >20 dB at any frequency.ResultsBetween the two surveys, the prevalence of high‐frequency HL (4, 6, and 8 kHz) increased from 73% to 94% but approached those of the aging general population after age adjustment. In TCSs aged >40 years at first survey, HL at the subsequent survey equaled that of controls. Self‐reported HL increased from seven (9%) at S1 to 20 (26%) at S3. At S1, age‐adjusted HL was identified in all (seven) TCSs reporting decreased hearing whereas at S3, hearing thresholds did not differ from controls in seven out of 20 patients reporting HL.ConclusionCBCT‐related ototoxicity causes high‐frequency HL, but in contrast to reports from follow‐up studies from the first post‐treatment decade, no major progression was found beyond the first post‐treatment decade for frequencies 0.125–8 kHz. Importantly, with extended follow‐up, hearing thresholds of patients approach those of the general population, possibly due to a less‐than‐additive effect with age‐related hearing loss (ARHL) in CBCT‐treated patients. Age‐and sex‐matching is strongly advised in long‐term follow‐up of CBCT‐related ototoxicity. Specificity for detecting ototoxicity with self‐reported questionnaires decreases with extended follow‐up.Level of Evidence3 Laryngoscope, 130:E515–E523, 2020

The project was financed by the Department of Otorhinolaryngology and Head and Neck Surgery.First, I would like to thank my main supervisor Marie Bunne, MD, PhD who has been my mentor both clinically and academically since I first started at Rikshospitalet in 2014. Her expertise within the field of otology/ear surgery has been inspiring and knowing that she would be my supervisor was one of the main reasons I did not hesitate to take on this project. Her door has always been open whenever I needed guidance or encouragement because progress was too slow for my liking. She helped me balance the clinical/surgical progress with the academic work and made sure I never fell behind in any of them. I would also like to thank for the countless hours spent on reading my manuscripts during weekends and vacations. This thesis would also not have been possible without my co-supervisor, Professor emerita Sophie D. Fosså, MD, PhD. She has helped me far beyond what could be expected from a co-supervisor and has always made time whenever I needed guidance. Further, this thesis would not have come together if it were not for her initiative and data collection over several decades. As one of the most published medical researchers in Norway, her expertise in writing and publishing articles has been invaluable and I feel privileged to have had such an experienced teacher. I would also like to express my gratitude to co-supervisor and Head of Department, Professor Terje A. Osnes, MD, PhD for believing in me and giving me the chance (and time) to work with this project combined with clinical work, for financial support, and for help with planning, organizing and publishing my work.Further I wish to thank my co-supervisor and statistician Professor Milada Småstuen, PhD, for helping me with the statistical analyses, saving me from countless hours of work with SPSS, for having patience, making sure my calculations were correct, and for explaining me statistics in an understandable way.