First Advisor

Deanna K. Meinke

First Committee Member

Diane L. Erdbruegger

Second Committee Member

Jennifer E. Weber

Degree Name

Doctor of Audiology

Document Type

Scholarly Project

Date Created

5-2024

Department

College of Natural and Health Sciences, Communication Sciences and Disorders, CSD Student Work

Abstract

Cancer is a major public health concern and is increasingly prevalent worldwide. Sung et al. (2021) states that there were 19.3 million new cases of cancer across the globe, and almost 10 million deaths related to cancer in 2021. Sung et al. (2021) also notes that the United States accounts for 8% of all global cases, with an average of 1.7 million new cases annually. The top five most common adult cancers in the United States include: (1) breast, (2) prostate, (3) lung and bronchus, (4) colorectal, and (5) invasive melanoma of the skin. These cancers can be treated with techniques such as surgery, radiation, biologic/immunotherapy, and chemotherapy. Some chemotherapeutics used in treatment regimens are toxic to the auditory system and cause unwanted hearing loss or other unwanted side effects, such as tinnitus or dizziness. This occurrence is known as ototoxicity. Known ototoxic chemotherapeutic agents affect the auditory system in different ways due to the way they interfere with cancer cells and non-cancerous cells within the body. This requires the need to monitor for ototoxicity during cancer treatment.

The responsibility for monitoring for potential ototoxicity of chemotherapeutics falls upon audiologists. The American Academy of Audiology (Durrant et al., 2009) and the American Speech-Language-Hearing Association (Fausti et al., 1993) have published guidelines for ototoxicity monitoring which are designed for only one chemotherapeutic, cisplatin. Other agents, such as carboplatin, oxaliplatin, nedaplatin, vincristine, vinblastine, and difluoromethylornithine (DFMO), have adverse effects on the auditory system in areas differing from cisplatin. Carboplatin causes damage to the spiral ganglion neurons and inner hair cell function before outer hair cells are affected (Dalian et al., 2012). Nedaplatin and oxaliplatin affect the auditory nerve fibers and both inner hair cell and outer hair cell stereocilia (Ding et al., 2012). Vincristine and vinblastine generally cause a hearing loss that is reversible once treatment is finished (Tazi et al., 2014) but also have neurotoxic affects to the auditory nerve fibers (Magge & DeAngelis, 2015). DFMO has been shown to decrease the number of polyamines in the inner ear (Nie et al., 2005) and affects the function of IHCs and OHCs (Salzer et al., 1990). Consequently, ototoxicity monitoring programs differ depending on the chemotherapy regime.

It is important for audiologists to understand the pathophysiology of the auditory damage that may occur for each chemotherapeutic to implement proper and effective ototoxic monitoring programs. In this document, audiologists are provided with examples of ototoxicity monitoring protocols for both responsive and non-responsive patients receiving carboplatin, oxaliplatin, nedaplatin, Difluoromethylornithine (DFMO), vincristine, and vinblastine. Gaps and limitations in the literature are identified and directions for further research are discussed, including the use of otoprotectants to prevent or decrease the ototoxic effects.

Abstract Format

html

Disciplines

Communication Sciences and Disorders

Extent

125 pages

Comments

Spring 2024 Graduate Dean's Citation for Outstanding Thesis, Dissertation, and Scholarly Project

Rights Statement

Copyright is held by the author.

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