Audiologic Follow-up in Patients With Head and Neck Cancer Treated With Cisplatin and Radiation

OBJECTIVES

Evaluate factors associated with adherence to ototoxicity monitoring among patients with head and neck cancer treated with cisplatin and radiation therapy at a tertiary care center.

METHODS

We performed a single-institution retrospective cohort study on adults with head and neck cancer treated with cisplatin and radiation therapy who participated in an ototoxicity monitoring program. The primary outcomes were rates of post-treatment audiograms at the following time points: one, three, six, 12, and greater than 12 months. Multivariable logistic regression was performed to identify risk factors associated with complete loss of follow-up after pre-treatment evaluation.

RESULTS

Two hundred ninety-four head and neck cancer patients were analyzed. Overall, 220 (74.8%) patients had at least one post-treatment audiogram; 58 (20.0%) patients had more than one audiogram. The time point with the highest follow-up rate was at 3 months (n = 170, 57.8%); rates at the remaining times ranged from 7.1% to 14.3%. When controlling for covariates, patients without insurance and those with stage IV cancers were associated with complete loss of audiologic follow-up (aOR = 7.18, 95% CI = 2.75-19.90; aOR = 1.96, 95% CI = 1.02-3.77, respectively). Among 156 patients recommended for a hearing aid, only 39 (24.8%) patients received one.

CONCLUSIONS

Head and neck cancer patients enrolled in an ototoxicity monitoring program demonstrate moderately high follow-up rates for at least one post-treatment audiogram. However, follow-up tapers dramatically after 6 months, and overall hearing aid utilization is low. Further research is needed to understand barriers to long-term audiologic follow-up and hearing aid utilization to decrease untreated hearing loss in cancer survivorship.

LEVEL OF EVIDENCE

Level 3 Laryngoscope, 133:3161-3168, 2023.

Hearing Outcomes in a Deintensification Trial of Adjuvant Therapy for HPV-Related Oropharyngeal Squamous Cell Carcinoma

OBJECTIVE

To explore whether deintensification of adjuvant therapy reduces ototoxicity among patients with human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC).

STUDY DESIGN

Retrospective cohort study.

SETTING

Single academic center.

METHODS

The ototoxicity rate among adult patients with HPV-related OPSCC enrolled in the Minimalist Trial (MINT), a prospective phase 2 trial of surgery followed by risk-adjusted deintensified adjuvant therapy (42 Gy radiation given alone or with a single 100 mg/m² dose of cisplatin), was compared to that among a historical cohort treated with standard adjuvant therapy (60-66 Gy radiation with up to three 100 mg/m² doses of cisplatin). Ototoxicity was defined as Common Terminology Criteria for Adverse Events v5.0 ≥ Grade 2. Mixed model analysis was performed to investigate the association between deintensified adjuvant therapy and treatment-related hearing loss.

RESULTS

A total of 29 patients (58 ears) were analyzed in the MINT cohort, and 27 patients (54 ears) in the historical cohort. The ototoxicity rate was 5% (n = 3/58 ears) in the MINT cohort and 46% (n = 25/54 ears) in the historical cohort (difference, 41%; 95% confidence interval [CI] = 27%-56%). Patients in the MINT cohort demonstrated a 95% decrease in risk of ototoxicity compared to those in the historical cohort (adjusted odds ratio: 0.05, 95% CI = 0.01-0.31). Differences in estimated marginal mean threshold shifts were statistically and clinically significant at frequencies ≥ 3 kHz.

CONCLUSION

The deintensified adjuvant therapy given in MINT led to less ototoxicity than standard adjuvant therapy among patients with HPV-related OPSCC.

Local Cisplatin Delivery in Mouse Reliably Models Sensorineural Ototoxicity Without Systemic Adverse Effects

Cisplatin is a lifesaving chemotherapeutic drug with marked ototoxic adverse effects. Cisplatin-induced hearing loss affects a significant part of cancer-surviving patients and is an unmet clinical need with important socioeconomic consequences. Unfortunately, in current preclinical animal models of cisplatin ototoxicity, which are mainly based on systemic delivery, important morbidity is observed, leading to premature death. This methodology not only raises obvious animal welfare concerns but also increases the number of animals used in ototoxicity studies to compensate for dropouts related to early death. To overcome these important limitations, we developed a local delivery model based on the application of a cisplatin solution directly into the otic bulla through a retroauricular approach. The local delivery model reliably induced significant hearing loss with a mean threshold shift ranging from 10 to 30 dB, strongly affecting the high frequencies (22 and 32 kHz). Importantly, mice did not show visible stress or distress indicators and no significant morbidity in comparison with a traditional systemic delivery control group of mice injected intraperitoneally with 10 mg/kg cisplatin, where significant weight loss >10% in all treated animals (without any recovery) led to premature abortion of experiments on day 3. Mass spectrometry confirmed the absence of relevant systemic uptake after local delivery, with platinum accumulation restricted to the cochlea, whereas important platinum concentrations were detected in the liver and kidney of the systemic cisplatin group. A clear correlation between the cochlear platinum concentration and the auditory threshold shift was observed. Immunohistochemistry revealed statistically significant loss of outer hair cells in the basal and apical turns of the cochlea and an important and statistically significant loss of auditory neurons and synapses in all cochlear regions. In conclusion, local cisplatin delivery induces robust hearing loss with minimal morbidity, thereby offering a reliable rodent model for human cisplatin ototoxicity, reducing the number of animals required and showing improved animal welfare compared with traditional systemic models.

Resveratrol upregulates miR-455-5p to antagonize cisplatin ototoxicity via modulating the PTEN-PI3K-AKT axis

Resveratrol is a non-flavonoid polyphenol compound that exists in many plants, and is considered an antitoxin. This study explores the effects from the regulation of miR-455-5p by resveratrol on cisplatin-induced ototoxicity via the PTEN-PI3K-AKT signaling pathway. For this, House Ear Institute-Organ of Corti 1 (HEI-OC1) cells were transfected with miR-455-5p inhibitor and treated with cisplatin and resveratrol, then cell proliferation, apoptosis, and oxidative stress were evaluated. A mouse model of hearing loss was established, and these mice were treated with cisplatin, resveratrol, or cisplatin combined with resveratrol, by intraperitoneal injection. The auditory brainstem response (ABR) threshold was measured, and hair cells were examined using immunofluorescence staining. The expression levels of miR-455-5p, PTEN, and PI3K/Akt proteins were examined. The results from our in-vitro experiments indicate that resveratrol promoted viability and reduced apoptosis and oxidative stress in cisplatin-induced HEI-OC1 cells. Resveratrol upregulated miR-455-5p, downregulated PTEN, and activated the PI3K-Akt axis. These effects of resveratrol were reversed by knock-down of miR-455-5p. The results from our in-vivo experiments indicate that resveratrol protected hearing and inhibited the hair-cell injury caused by cisplatin ototoxicity. Resveratrol also upregulated miR-455-5p, downregulated PTEN, and activated the PTEN-PI3K-Akt axis in cochlear tissues from cisplatin-treated mice. These results indicate that resveratrol upregulates miR-455-5p to target PTEN and activate the PI3K-Akt signaling pathway to counteract cisplatin ototoxicity.

Circadian vulnerability of cisplatin-induced ototoxicity in the cochlea

The chemotherapeutic agent cisplatin is renowned for its ototoxic effects. While hair cells in the cochlea are established targets of cisplatin, less is known regarding the afferent synapse, which is an essential component in the faithful temporal transmission of sound. The glutamate aspartate transporter (GLAST) shields the auditory synapse from excessive glutamate release, and its loss of function increases the vulnerability to noise, salicylate, and aminoglycosides. Until now, the involvement of GLAST in cisplatin-mediated ototoxicity remains unknown. Here, we test in mice lacking GLAST the effects of a low-dose cisplatin known not to cause any detectable change in hearing thresholds. When administered at nighttime, a mild hearing loss in GLAST KO mice was found but not at daytime, revealing a potential circadian regulation of the vulnerability to cisplatin-mediated ototoxicity. We show that the auditory synapse of GLAST KO mice is more vulnerable to cisplatin administration during the active phase (nighttime) when compared to WT mice and treatment during the inactive phase (daytime). This effect was not related to the abundance of platinum compounds in the cochlea, rather cisplatin had a dose-dependent impact on cochlear clock rhythms only after treatment at nighttime suggesting that cisplatin can modulate the molecular clock. Our findings suggest that the current protocols of cisplatin administration in humans during daytime may cause a yet undetectable damage to the auditory synapse, more so in already damaged ears, and severely impact auditory sensitivity in cancer survivors.

A666-conjugated nanoparticles target prestin of outer hair cells preventing cisplatin-induced hearing loss

Background

The delivery of treatment agents to inner ear with drug delivery system (DDS) has been under investigation to overcome the limitations of the conventional therapeutic agents in curing or alleviating the cisplatin ototoxicity.

Methods

In the present study, a novel targeted dexamethasone (DEX)-loaded DDS, A666-DEX-NP, was constructed for prevention from cisplatin-induced hearing loss. A666-(CLEPRWGFGWWLH) peptides specifically bind to prestin, which is limited to the outer hair cells (OHCs). HEI-OC1 and cisplatin-treated guinea pigs (12 mg/kg, intraperitoneal) were used as in vitro and in vivo models for investigating the targeting and protective efficiency against cisplatin.

Results

As expected, compared to A666-unconjugated nanoparticles (NP), A666-conjugated coumarin 6-labeled NP showed active targeting to OHCs. Furthermore, A666-coumarin 6-labeled NP could be significantly internalized by HEI-OC1 cells via the A666-prestin interaction. This facilitated the uptake of cells pretreated with A666-DEX-NP, followed by the cisplatin-treated group, which led to enhanced cell viability, reduced apoptotic properties, and decreased reactive oxygen species levels as compared to cells pretreated with DEX or DEX-NP, 4 hours in advance of cisplatin treatment. In cisplatin-treated guinea pigs, pretreatment with A666-DEX-NP effectively preserved OHCs and showed significant hearing protection at 4, 8, and 16 kHz as compared to pretreatment with saline, DEX, or DEX-NP formulation.

Conclusion

This OHC-targeting DDS provides a novel strategy for DEX application that can be potentially used to combat cisplatin ototoxicity.

Current practice of ototoxicity management across the United Kingdom (UK)

OBJECTIVE

Effective management of patients diagnosed with ototoxicity is needed to reduce hearing and balance damage which affects communication and life quality. Despite widespread recommendations to monitor and manage ototoxicity in an early and effective manner, there is limited evidence to support the actual implementation of these recommendations for affected patient groups in healthcare services across the UK with limited publications available. In this study, an online questionnaire analysed the current practice of ototoxicity management and patient pathways across the UK once the diagnosis of ototoxicity was confirmed, targeting Audiologists, ENTs/AVPs and GPs.

DESIGN

Qualitative Survey Study.

STUDY SAMPLE

A randomised sample of hearing services in the UK, including audiology departments; GP practices and local health settings were targeted with a total of 134 completed surveys.

RESULTS

About 72% reported the absence of ototoxicity management protocols within their centre. Results depicted great inconsistency and variation across the UK in ototoxicity management services provided, treatment modification, monitoring and referral pathways.

CONCLUSION

Developing and advocating national guidelines are intended not only to inform clinical decision making but to provide minimum standards of care in ototoxicity management and offer greater awareness and education to improve patients' quality of life.

Reversible p53 inhibition prevents cisplatin ototoxicity without blocking chemotherapeutic efficacy

Cisplatin is a widely used chemotherapy drug, despite its significant ototoxic side effects. To date, the mechanism of cisplatin‐induced ototoxicity remains unclear, and hearing preservation during cisplatin‐based chemotherapy in patients is lacking. We found activation of the ATM‐Chk2‐p53 pathway to be a major determinant of cisplatin ototoxicity. However, prevention of cisplatin‐induced ototoxicity is hampered by opposite effects of ATM activation upon sensory hair cells: promoting both outer hair cell death and inner hair cell survival. Encouragingly, however, genetic or pharmacological ablation of p53 substantially attenuated cochlear cell apoptosis, thus preserving hearing. Importantly, systemic administration of a p53 inhibitor in mice bearing patient‐derived triple‐negative breast cancer protected auditory function, without compromising the anti‐tumor efficacy of cisplatin. Altogether, these findings highlight a novel and effective strategy for hearing protection in cisplatin‐based chemotherapy.

Dose-dependent protection on cisplatin-induced ototoxicity - an electrophysiological study on the effect of three antioxidants in the Sprague-Dawley rat animal model

BACKGROUND

Sprague-Dawley rats were used as an acute cisplatin ototoxicity model to compare the chemo-protective efficacy of 2 sulphur-containing antioxidants (D-methionine, N-L-acetylcysteine) and 1 seleno-organic compound (ebselen). Each putative chemo-protective agent was tested at 3 different dosages in order to assess the influence of dose on auditory preservation.

MATERIAL/METHODS

A total of 40 Sprague-Dawley albino male rats were used in the study. Animals were divided into 10 groups, 3 groups of different doses for each protective agent and a cisplatin-treated control group. The animals were weight-matched before drug exposure to ensure similar weights in all groups. Auditory function was assessed with auditory brainstem responses and distortion product otoacoustic emissions at time zero and at 96 hours post-treatment.

RESULTS

At the post-treatment follow-up no significant threshold change at 8 kHz was found in the D-Met- and NAC-treated groups. All ebselen-treated animals presented significant threshold elevations. At 12 and 16 kHz, only the groups treated with 300, 450 mg/kg of D-Met and 475 mg/kg of NAC presented thresholds comparable to the pre-treatment ABR data. The ebselen-treated animals presented significant threshold shifts and showed the highest threshold elevations. The DPOAE data analysis showed that only the animals from the 350 mg/kg D-met group presented lack of statistical differences between the pre and post recordings.

CONCLUSIONS

Considering the outcome from the ABR and DPOAE analyses together, only the 350 mg/kg D-met group presented a complete auditory preservation against the 14 mg/kg cisplatin administered i.v. Data from ebselen pre-treated Sprague-Dawley albino male rats demonstrate that ebselen dosages up to 12 mg/kg given by i.p. administration lack auditory preservation in this species.