Comprehensive Audiometric Analysis of Hearing Impairment and Tinnitus After Cisplatin-Based Chemotherapy in Survivors of Adult-Onset Cancer

Malignant ovarian and testicular germ cell tumors: Common characteristics but different prognoses

Both ovarian and testicular germ cell tumors (GCTs) arise from the primordial germ cell and share many similarities. Both malignancies affect mainly young patients, show remarkable responsiveness to cisplatin-based therapy, and have an excellent prognosis, which also highlights the importance of minimizing long-term side effects. However, certain differences can be noted: The spreading of the disease differs, and the staging system and treatment recommendations are dissimilar. Moreover, the prognosis for ovarian GCTs is significantly inferior to that for testicular cancer, as exemplified in this review comparing the survival in Swedish patients diagnosed with testicular (1995-2022) and ovarian (1990-2018) GCTs. The 5-year overall survival in ovarian GCTs was 85.2%, versus 98.2% for testicular GCTs. How can this be explained? One reason may be the difference in knowledge, experience, and evidence because the incidence rate of testicular cancer is more than 15 times that of ovarian GCTs. Given the rarity of the disease in women and the lack of established guidelines, a comprehensive understanding of the disease and treatment decisions is challenging. The main objective of this review is to derive insights from testicular GCTs (seminoma and non-seminoma) by reviewing etiological, tumor biological, and clinical knowledge, and to thereafter suggest actions for ovarian GCTs based on this. We hypothesize that by adopting specific treatment strategies from testicular GCTs-including de-escalating adjuvant chemotherapy for low-risk patients and implementing more standardized and intensive treatment protocols in cases of relapse-we can improve the prognosis and minimize long-term side effects in ovarian GCT patients.

Inhibition of CISD1 attenuates cisplatin-induced hearing loss in mice via the PI3K and MAPK pathways

Cisplatin is an effective chemotherapeutic drug for different cancers, but it also causes severe and permanent hearing loss. Oxidative stress and mitochondrial dysfunction in cochlear hair cells (HCs) have been shown to be important in the pathogenesis of cisplatin-induced hearing loss (CIHL). CDGSH iron sulfur domain 1 (CISD1, also known as mitoNEET) plays a critical role in mitochondrial oxidative capacity and cellular bioenergetics. Targeting CISD1 may improve mitochondrial function in various diseases. However, the role of CISD1 in cisplatin-induced ototoxicity is unclear. Therefore, this study was performed to assess the role of CISD1 in cisplatin-induced ototoxicity. We found that CISD1 expression was significantly increased after cisplatin treatment in both HEI-OC1 cells and cochlear HCs. Moreover, pharmacological inhibition of CISD1 with NL-1 inhibited cell apoptosis and reduced mitochondrial reactive oxygen species accumulation in HEI-OC1 cells and cochlear explants. Inhibition of CISD1 with small interfering RNA in HEI-OC1 cells had similar protective effects. Furthermore, NL-1 protected against CIHL in adult C57 mice, as evaluated by the auditory brainstem response and immunofluorescent staining. Mechanistically, RNA sequencing revealed that NL-1 attenuated CIHL via the PI3K and MAPK pathways. Most importantly, NL-1 did not interfere with the antitumor efficacy of cisplatin. In conclusion, our study revealed that targeting CISD1 with NL-1 reduced reactive oxygen species accumulation, mitochondrial dysfunction, and apoptosis via the PI3K and MAPK pathways in HEI-OC1 cell lines and mouse cochlear explants in vitro, and it protected against CIHL in adult C57 mice. Our study suggests that CISD1 may serve as a novel target for the prevention of CIHL.

Statins as anti-tumor agents: A paradigm for repurposed drugs

BACKGROUND

Statins, frequently prescribed medications, work by inhibiting the rate-limiting enzyme HMG-CoA reductase (HMGCR) in the mevalonate pathway to reduce cholesterol levels. Due to their multifaceted benefits, statins are being adapted for use as cost-efficient, safe and effective anti-cancer treatments. Several studies have shown that specific types of cancer are responsive to statin medications since they rely on the mevalonate pathway for their growth and survival.

RECENT FINDINGS

Statin are a class of drugs known for their potent inhibition of cholesterol production and are typically prescribed to treat high cholesterol levels. Nevertheless, there is growing interest in repurposing statins for the treatment of malignant neoplastic diseases, often in conjunction with chemotherapy and radiotherapy. The mechanism behind statin treatment includes targeting apoptosis through the BCL2 signaling pathway, regulating the cell cycle via the p53-YAP axis, and imparting epigenetic modulations by altering methylation patterns on CpG islands and histone acetylation by downregulating DNMTs and HDACs respectively. Notably, some studies have suggested a potential chemo-preventive effect, as decreased occurrence of tumor relapse and enhanced survival rate were reported in patients undergoing long-term statin therapy. However, the definitive endorsement of statin usage in cancer therapy hinges on population based clinical studies with larger patient cohorts and extended follow-up periods.

CONCLUSIONS

The potential of anti-cancer properties of statins seems to reach beyond their influence on cholesterol production. Further investigations are necessary to uncover their effects on cancer promoting signaling pathways. Given their distinct attributes, statins might emerge as promising contenders in the fight against tumorigenesis, as they appear to enhance the efficacy and address the limitations of conventional cancer treatments.

Combined genetic polymorphisms of the GSTT1 and NRF2 genes increase susceptibility to cisplatin-induced ototoxicity: A preliminary study

OBJECTIVE

The genotype-phenotype relationship in cisplatin-induced ototoxicity remains unclear. By assessing early shifts in distortion product otoacoustic emission (DPOAE) levels after initial cisplatin administration, we aimed to discriminate patients' susceptibility to cisplatin-induced ototoxicity and elucidate their genetic background.

STUDY DESIGN

A prospective cross-sectional study.

SETTING

Tertiary referral hospital in Japan.

PATIENTS

Twenty-six patients with head and neck cancer were undergoing chemoradiotherapy with three cycles of 100 mg/m2 cisplatin.

INTERVENTIONS

Repetitive pure-tone audiometry and DPOAE measurements, and blood sampling for DNA extraction were performed. Patients were grouped into early ototoxicity presence or absence based on whether DPOAE level shifts exceeded the corresponding reference limits of the 21-day test interval.

MAIN OUTCOME MEASURES

Hearing thresholds after each cisplatin cycle, severity of other adverse events, and polymorphisms in cisplatin-induced ototoxicity-associated genes were compared.

RESULTS

Early ototoxicity was present in 14 and absent in 12 patients. Ototoxicity presence on DPOAEs was associated with greater progression of hearing loss in frequencies ≥2 kHz throughout therapy and with higher ototoxicity grades compared with ototoxicity absence. Ototoxicity was further associated with grade ≥2 nausea. Ototoxicity presence was genetically associated with the GSTT1 null genotype and G-allele of NFE2L2 rs6721961, whereas ototoxicity absence was associated with the GSTM1 null genotype. Dose-dependent progression of hearing loss was the greatest in the combined genotype pattern of GSTT1 null and the T/G or G/G variants of rs6721961.

CONCLUSION

Early DPOAE changes reflected genetic vulnerability to cisplatin-induced ototoxicity. Hereditary insufficiency of the antioxidant defense system causes severe cisplatin-induced hearing loss and nausea.

Application of organoids in otolaryngology: head and neck surgery

PURPOSE

The purpose of this review is to systematically summarize the application of organoids in the field of otolaryngology and head and neck surgery. It aims to shed light on the current advancements and future potential of organoid technology in these areas, particularly in addressing challenges like hearing loss, cancer research, and organ regeneration.

METHODS

Review of current literature regrading organoids in the field of otolaryngology and head and neck surgery.

RESULTS

The review highlights several advancements in the field. In otology, the development of organoid replacement therapies offers new avenues for treating hearing loss. In nasal science, the creation of specific organoid models aids in studying nasopharyngeal carcinoma and respiratory viruses. In head and neck surgery, innovative approaches for squamous cell carcinoma prediction and thyroid regeneration using organoids have been developed.

CONCLUSION

Organoid research in otolaryngology-head and neck surgery is still at an early stage. This review underscores the potential of this technology in advancing our understanding and treatment of various conditions, predicting a transformative impact on future medical practices in these fields.

4-octyl itaconate alleviates cisplatin-induced ferroptosis possibly via activating the NRF2/HO-1 signalling pathway

Ferroptosis, characterized by iron-dependent lipid reactive oxygen species (ROS) accumulation, plays a pivotal role in cisplatin-induced ototoxicity. Existing research has suggested that in cisplatin-mediated damage to auditory cells and hearing loss, ferroptosis is partially implicated. 4-Octyl itaconate (4-OI), derived from itaconic acid, effectively permeates cell membranes, showcasing potent anti-inflammatory as well as antioxidant effects in several disease models. Our study aimed to investigate the effect of 4-OI on cisplatin-induced ferroptosis and the underlying molecular mechanisms. The survival rates of HEI-OC1 cells and mice cochlea hair cells were measured by CCK8 and immunofluorescence, respectively. The auditory brainstem response (ABR) audiometry was used to detect changes in hearing thresholds in mice before and after treatment. Levels of ROS were evaluated by DCFH-DA. Real-time PCR quantified inflammatory cytokines TNF-α, IL-6 and IL-1β. Network Pharmacology and RNA sequencing (RNA-seq) analysis of the potential mechanism of 4-OI resistance to cisplatin-induced ferroptosis. The expressions of ferroptosis-related factors (GPX4, SLC7A11 and PTGS2) and important antioxidant factors (NRF2, HO-1, GCLC and NQO1) were tested by real-time PCR, Western blot and immunofluorescence. Results demonstrated cisplatin-induced significant ROS and inflammatory factor release, reduced NRF2 expression, hindered nuclear translocation and activated ferroptosis. Pretreatment with 4-OI exhibited anti-inflammatory and antioxidant effects, along with resistance to ferroptosis, ultimately mitigating cisplatin-induced cell loss. In the present study, we show that 4-OI inhibits cisplatin-induced ferroptosis possibly through activation of the NRF2/HO-1 signalling pathway, thereby exerting a protective effect against cisplatin-induced damage to auditory cells, and providing a new therapeutic strategy for cisplatin-induced hearing loss.

Cholesterol metabolism in tumor microenvironment: cancer hallmarks and therapeutic opportunities

Cholesterol is crucial for cell survival and growth, and dysregulation of cholesterol homeostasis has been linked to the development of cancer. The tumor microenvironment (TME) facilitates tumor cell survival and growth, and crosstalk between cholesterol metabolism and the TME contributes to tumorigenesis and tumor progression. Targeting cholesterol metabolism has demonstrated significant antitumor effects in preclinical and clinical studies. In this review, we discuss the regulatory mechanisms of cholesterol homeostasis and the impact of its dysregulation on the hallmarks of cancer. We also describe how cholesterol metabolism reprograms the TME across seven specialized microenvironments. Furthermore, we discuss the potential of targeting cholesterol metabolism as a therapeutic strategy for tumors. This approach not only exerts antitumor effects in monotherapy and combination therapy but also mitigates the adverse effects associated with conventional tumor therapy. Finally, we outline the unresolved questions and suggest potential avenues for future investigations on cholesterol metabolism in relation to cancer.

Drug-induced hearing loss: Listening to the latest advances

Sensorineural hearing loss (SNHL) is the most common type of hearing loss. Causes include degenerative changes in the sensory hair cells, their synapses and/or the cochlear nerve. As human inner ear hair cells have no capacity for regeneration, their destruction is irreversible and leads to permanent hearing loss. SNHL can be genetically inherited or acquired through ageing, exposure to noise or ototoxic drugs. Ototoxicity generally refers to damage to the structures and functions of the inner ear following exposure to specific drugs. Ototoxicity can be multifactorial, causing damage to cochlear hair cells or cells with homeostatic functions that modulate cochlear hair cell function. Clinical strategies to limit ototoxicity include identifying patients at risk, monitoring drug concentrations, performing serial hearing assessments and switching to less ototoxic therapy. This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, using the PubMed® database. The search terms "ototoxicity", "hearing loss" and "drugs" were combined. We included studies published between September 2013 and June 2023, and focused on medicines and drugs used in hospitals. The review highlighted a number of articles reporting the main drug classes potentially involved: namely, immunosuppressants, antimalarials, vaccines, antibiotics, antineoplastic agents, diuretics, nonsteroidal anti-inflammatory drugs and analgesics. The presumed ototoxic mechanisms were described, together with the therapeutic and preventive options developed over the last ten years.

Kremen1 regulates the regenerative capacity of support cells and mechanosensory hair cells in the zebrafish lateral line

Mechanosensory hair cells in the inner ear mediate the sensations of hearing and balance, and in the specialized lateral line sensory system of aquatic vertebrates, the sensation of water movement. In mammals, hair cells lack the ability to regenerate following damage, resulting in sensory deficits. In contrast, non-mammalian vertebrates, such as zebrafish, can renew hair cells throughout their lifespan. Wnt signaling is required for development of inner ear and lateral line hair cells and regulates regeneration. Kremen1 inhibits Wnt signaling and hair cell formation, though its role in regeneration is unknown. We used a zebrafish kremen1 mutant line to show overactive Wnt signaling results in supernumerary support cells and hair cell regeneration without increased proliferation, in contrast with the previously described role of Wnt signaling during hair cell regeneration. This work allows us to understand the biology of mechanosensory hair cells and how regeneration might be promoted following damage.

Prevention and treatment of cisplatin-induced ototoxicity in adults: A systematic review

OBJECTIVES

Ototoxicity is a common disabling side effect of platinum-based chemotherapy. This study aimed to assess the evidence on the management of platinum-induced ototoxicity in adult cancer patients.

METHODS

Four databases were searched up to 1 November 2022. Original studies were included if they reported on a pharmacologic or non-pharmacologic intervention to prevent or treat platinum ototoxicity in adults. The articles' quality was assessed via two grading scales.

RESULTS

Nineteen randomised controlled trials and five quasi-experimental studies with 1673 patients were analysed. Eleven interventions were identified, nine pharmacological and two non-pharmacological. Six of the interventions (sodium thiosulphate, corticoids, sertraline, statins, multivitamins and D-methionine) showed mild benefits in preventing cisplatin-induced ototoxicity. Only one trial assessed corticoids as a potential treatment. Overall, only six trials were deemed with a low risk of bias. The majority of studies inadequately documented intervention-related adverse effects, thereby limiting safety conclusions.

CONCLUSIONS

Current interventions have mild benefits in preventing cisplatin-induced ototoxicity in adult cancer patients. Sodium thiosulphate is the most promising intervention as a preventive strategy. Rigorous, high-quality research is warranted, encompassing an evaluation of all potential symptoms and innovative treatment modalities.

Deep Learning for Subtypes Identification of Pure Seminoma of the Testis

The most critical step in the clinical diagnosis workflow is the pathological evaluation of each tumor sample. Deep learning is a powerful approach that is widely used to enhance diagnostic accuracy and streamline the diagnosis process. In our previous study using omics data, we identified 2 distinct subtypes of pure seminoma. Seminoma is the most common histological type of testicular germ cell tumors (TGCTs). Here we developed a deep learning decision making tool for the identification of seminoma subtypes using histopathological slides. We used all available slides for pure seminoma samples from The Cancer Genome Atlas (TCGA). The developed model showed an area under the ROC curve of 0.896. Our model not only confirms the presence of 2 distinct subtypes within pure seminoma but also unveils the presence of morphological differences between them that are imperceptible to the human eye.

Drug screening identifies aldose reductase as a novel target for treating cisplatin-induced hearing loss

Cisplatin is a frequently used chemotherapeutic medicine for cancer treatment. Permanent hearing loss is one of the most serious side effects of cisplatin, but there are few FDA-approved medicines to prevent it. We applied high-through screening and target fishing and identified aldose reductase, a key enzyme of the polyol pathway, as a novel target for treating cisplatin ototoxicity. Cisplatin treatment significantly increased the expression level and enzyme activity of aldose reductase in the cochlear sensory epithelium. Genetic knockdown or pharmacological inhibition of aldose reductase showed a significant protective effect on cochlear hair cells. Cisplatin-induced overactivation of aldose reductase led to the decrease of NADPH/NADP+ and GSH/GSSG ratios, as well as the increase of oxidative stress, and contributed to hair cell death. Results of target prediction, molecular docking, and enzyme activity detection further identified that Tiliroside was an effective inhibitor of aldose reductase. Tiliroside was proven to inhibit the enzymatic activity of aldose reductase via competitively interfering with the substrate-binding region. Both Tiliroside and another clinically approved aldose reductase inhibitor, Epalrestat, inhibited cisplatin-induced oxidative stress and subsequent cell death and thus protected hearing function. These findings discovered the role of aldose reductase in the pathogenesis of cisplatin-induced deafness and identified aldose reductase as a new target for the prevention and treatment of hearing loss.

Evaluation and analysis of risk factors of hearing impairment for nasopharyngeal carcinoma treated using intensity-modulated radiotherapy

BACKGROUND

Treating nasopharyngeal carcinoma (NPC) with radiotherapy frequently causes hearing impairment (HI). HI risk data haven't been evaluated quantitatively. This study aimed to analyze the probability of HI and sever HI (SHI), develop a nomogram to quantify individual prediction, and provide dose limitation suggestions.

METHODS AND MATERIALS

This single-center, retrospective study was conducted based on 588 adolescents and young adults with non-metastatic NPC treated using intensity modulated radiation therapy (IMRT) at Sun Yat-sen University Cancer Center between 2010 and 2016. A least absolute shrinkage and selection operator (LASSO) logistic regression model and univariate analysis were used to screen potential risk factors. The concordance index and a calibration curve evaluated the nomogram models' predictive ability, with bootstrap resampling validation.

RESULTS

We analyzed 588 patients with NPC, with a median follow-up of 103.4 months. HI occurred in 39.5 % of patients, with 29.7 % experiencing SHI. Two factors were classified as precursors for HI (volume 45 Gy of the inner ear (IEV45) and volume 50 Gy of the internal auditory canal (IACV50)), and IACmin and IACV60 for SHI, respectively. Prognostic nomograms were developed to predict HI and SHI probabilities, showing excellent discriminative abilities (c-index values = 0.806 and 0.793, respectively). We also suggested IEV45 < 50 % and/or IACV50 < 40 % as rational dose limitations for HI, and IACmin < 44 Gy and/or the IACV60 < 40 % for SHI.

CONCLUSION

Comprehensive analysis could predict the risk of HI and SHI in NPC after IMRT, proposing rational dose limitations and improving long-term quality of life.

Analysis of the incidence, characteristics, and risk factors of complications during induction chemotherapy in children with high-risk neuroblastoma

Patients with high-risk neuroblastoma (HR-NB) exhibit suboptimal 5-year survival rates, leading to a widespread international preference for high-intensity chemotherapeutic regimens in these children. We analyzed the incidence and risk factors for complications during induction chemotherapy in children with HR-NB and tried to assist clinicians in predicting such complications and optimizing therapeutic strategy. The clinical data of children with HR-NB admitted to our hospital from January 2007 to December 2019 were retrospectively analyzed. The incidence, characteristics, and risk factors of complications (infection, hemorrhage, and chemotherapy-related adverse reactions (CRAR)) requiring hospitalization during induction chemotherapy in these children were explored. (1) A total of 108 patients with HR-NB were included in the final analysis. The overall infection rate was 92.6% (100/108), with the highest incidence of 71.3% observed during the first cycle. FN, bacterial infection, as well as fungal infection were common infectious complications in children with HR-NB during induction chemotherapy. (2) The overall hemorrhage rate was 24.1% (26/108), with the highest incidence of 14.8% also observed in the first cycle. Among the children with hemorrhage, there were 72% with bone marrow involved, while 65.0% of them had a high vanillylmandelic acid (VMA) value. And children with hemorrhage also exhibited neuron-specific enolase (NSE) ≥ 200 µg/L in 88.5% of cases and lactic dehydrogenase (LDH) ≥ 1000U/L in 73.1% of cases. (3) The incidence of CRAR rate was 100%, and 99.1% (107/108) patients experienced myelosuppression. The incidence of myelosuppression peaked in the third cycle, reaching up to 85.2%. Most children suffered severe myelosuppression existed with bone marrow metastases (76.3%), abnormal VMA (67.5%), and LDH ≥ 1000 U/L (60%). (4) Non-myelosuppressive adverse effects were observed in 75.9% children (82/108), with the highest incidence occurring in the third cycle at 42.6%. (5) Patients who experienced three types of complications had a lower median survival time (MST) of 54.4 months, a 3-year event-free survival (EFS) rate of (44.2 ± 10.7)%, and a 3-year overall survival (OS) rate of (75.8 ± 8.6)%, in comparison to those with only one or two complications, who had a higher MST of 59.5 months, a 3-year EFS rate of (73.5 ± 5.2)% (X2 = 10.457, P = 0.001), and a 3-year OS rate of (84.8 ± 4.1)% (X2 = 10.511, P = 0.001).

CONCLUSION

The presence of bone marrow involved and increased VMA were high-risk factors for infection, while NSE ≥ 200 µg/L and LDH ≥ 1000 U/L were high-risk factors for hemorrhage. For those children who had experienced severe myelosuppression, the presence of bone marrow metastases, increased VMA, and LDH ≥ 1000 U/L were their risk factors. The presence of bone involvement was a high-risk factor for children to have non-myelosuppressive adverse effects. Complications that arise during induction chemotherapy could negatively impact the children's prognosis and overall quality of life.

WHAT IS KNOWN

• The high-risk neuroblastoma (HR-NB) had a worse prognosis; there was a general international preference for high-intensity chemotherapeutic regimens in the induction phase to these children.

WHAT IS NEW

• We analyzed the incidence and risk factors of complications during induction chemotherapy in children with HR-NB and tried to help clinicians predict such complications and adopt optimized therapeutic strategy.

Ototoxicity associated with high-dose carboplatin for patients with previously treated germ cell tumors

BACKGROUND

High-dose carboplatin is an essential part of curative high-dose chemotherapy (HDCT) for patients with previously treated germ cell tumors (GCTs). Although hearing loss (HL) is a known side effect of HDCT, data on its severity and characteristics are limited.

METHODS

Eligible patients received HDCT for GCTs from 1993 to 2017 and had audiograms before and after HDCT. HL severity was classified by American Speech-Language-Hearing Association criteria, and mean change in hearing threshold at each frequency (0.25-8 kHz) was estimated from pre- to post-HDCT and between HDCT cycles.

RESULTS

Of 115 patients (median age, 32 years), 102 (89%) received three cycles of HDCT. Of 106 patients with normal hearing to mild HL in the speech frequencies (0.5-4 kHz) before HDCT, 70 (66%) developed moderate to profound HL in the speech frequencies after HDCT. Twenty-five patients (22%) were recommended for hearing aids after HDCT. Patients with moderate to profound HL isolated to the higher frequencies (6-8 kHz) before HDCT were more likely to develop moderate to profound HL in the speech frequencies after HDCT (94% vs. 61%; p = .01) and to be recommended for hearing aids (39% vs. 18%; p = .05).

CONCLUSIONS

HL was frequent after HDCT for GCTs, with most patients developing at least moderate HL in the speech frequencies and approximately one in five recommended for hearing aids. Moderate to profound HL isolated to high frequencies at baseline was predictive of more clinically significant hearing impairment after HDCT.

PLAIN LANGUAGE SUMMARY

Some patients with germ cell tumors, the most common malignancy in adolescent and young adult men, are not cured with standard-dose chemotherapy and require high-dose chemotherapy (HDCT). Using detailed hearing assessments of patients receiving HDCT, we found that most patients developed significant hearing loss and that one in five needed hearing aids. Thus, strategies to reduce this side effect are urgently needed, and all patients receiving HDCT should have a hearing test after therapy.

Testicular Tumors

BACKGROUND

Germ-cell tumors of the testes are the most common type of malignant tumor in men aged 20 to 40. Their incidence in Germany is 10 per 100 000 men per year, with an estimated 4200 new cases annually.

METHODS

This selective review is based on the recommendations of the German clinical practice guideline on the diagnosis, treatment and follow-up care of testicular germ-cell tumors, as well as on pertinent original articles and reviews.

RESULTS

The treatment of germ-cell tumors requires an interdisciplinary approach comprising resection of the affected testis followed by further steps that depend on the histological type and stage of the tumor, which may include active surveillance, chemotherapy, radiotherapy, further surgery, or some combination of these measures. Two-thirds of germ-cell tumors are diagnosed in clinical stage I, when they are still confined to the testis; one-third are already metastatic when diagnosed, with organ metastases in 10-15%. Stage-based multimodal treatment approaches are associated with cure rates of more than 99% for stage I tumors and 67-95% for advanced metastatic disease, depending on the degree of progression.

CONCLUSION

For patients with early-stage tumors, overtreatment should be avoided in order to minimize long-term sequelae. For those whose tumors are in advanced stages, it must be decided which patients should receive intensified treatment to optimize the outcome. Multimodal treatment approaches are associated with high cure rates even for patients with metastatic disease.

Adverse health outcomes and global quality of life in long-term testicular cancer survivors: a longitudinal 30-year perspective

BACKGROUND

The aim of this study was to characterize the prevalence of self-reported adverse health outcomes (AHOs), track changes in AHOs, and examine their impact on health-related quality of life (HrQoL) in testicular cancer survivors (TCSs) who were diagnosed between 1980 and 1994. These assessments were conducted during two survey waves (SWs), with the first occurring ∼12 years after surgery-only or platinum-based chemotherapy (PBCT), and the second ∼28 years after initial treatment. The study primarily focused on 'typical AHOs', which included Peripheral Sensory Neuropathy (PSN), Raynaud's phenomenon, Tinnitus, and Hearing loss.

PATIENTS AND METHODS

A total of 427 TCSs were included in the evaluation, distributed as follows: surgery-only group (n = 155), PBCT-standard group with ≤850 mg cisplatin (n = 222), and PBCT-high group with >850 mg cisplatin (n = 50). For comparison of HrQoL, men from the general population served as a control group (referred to as 'Norms'). The statistical significance level was set at P < 0.05, and clinical importance, in terms of testing HrQoL differences, was defined as Δ ≥2.5 points.

RESULTS

A higher number of TCSs who underwent PBCT reported experiencing typical AHOs compared with those who had surgery only. The highest prevalence rates were observed among TCSs who had undergone PBCT-high. Further, the number of TCSs describing typical AHOs, except Raynaud's phenomenon, increased during the observation period of 16 years. At the last SW, a median of 4 AHOs (any type) were reported after PBCT-high compared with a median of 2 AHOs after Surgery-only or after PBCT-standard. With Surgery-only as reference, PBCT-high, but not PBCT-standard, was associated with decreasing physical HrQoL in the last SW (A2 Regression coefficient: -4.3; P = 0.008). When comparing all TCSs with Norms no clinically important difference in physical and mental HrQoL was observed at either SW. However, at the last SW, TCSs after PBCT-high therapy represented a subgroup of TCSs with clinically important impairment of HRQoL. Of the typical AHOs, only PSN reduced HrQoL. Chronic fatigue, pain, anxiety/depression, sexual dysfunction, unemployment, being single, and low education were additional covariates.

CONCLUSIONS

After a median of 28 years since their treatment, HrQoL in TCSs was found to be comparable to that of Norms. This similarity held true even though AHOs, especially after PBCT-high, were becoming more prevalent among TCSs. The study revealed that individuals with a history of PBCT-high are at a high risk of experiencing a significantly increased prevalence of long-term AHOs, which subsequently leads to diminished HrQoL. It is crucial to recognize and provide specialized attention to these TCSs during lifelong follow-up care.

Subjective and Objective Hearing Loss Among US Adult Cancer Survivors

Importance

Cancer survivors are at a higher risk of developing hearing loss (HL) due to older age, chemotherapy, and radiotherapy. However, the prevalence of HL among US cancer survivors remains unknown. Additionally, there is a lack of uniform HL screening guidelines for this enlarging population.

Objective

To estimate the prevalence of subjective HL and objective HL by audiometry test among cancer survivors and compare them with the general population as well as to assess the performance of subjective HL questions in detecting true (ie, audiometry-confirmed) HL.

Design, Setting, and Participants

In a cross-sectional design, adults between ages 20 and 80 years who had audiometry testing and responded to a hearing questionnaire from the National Health and Nutrition Examination Survey (2011-2012, 2015-2016, and 2017 to March 2020 prepandemic survey cycles) were selected. Data analysis was conducted from August 13, 2022, to July 26, 2023.

Main Outcomes and Measures

The weighted prevalence of subjective HL (troublesome hearing and tinnitus) and objective HL (speech-frequency HL and high-frequency HL) by audiometry were calculated. Analyses with χ2 testing and multiadjusted logistic regression models were used to compare HL between cancer survivors and the general population. To evaluate the performance of subjective HL questions as a tool to screen for objective HL by audiometry, areas under the curve were estimated using age- and gender-adjusted logistic regression.

Results

Among the total 9337 participants (weighted n = 90 098 441; 51.2% women), 10.3% were cancer survivors. Compared with the general population, cancer survivors had a higher prevalence of troublesome hearing (adjusted odds ratio [AOR], 1.43; 95% CI, 1.11-1.84), tinnitus (AOR, 1.28; 95% CI, 0.94-1.74), speech-frequency HL (AOR, 1.43; 95% CI, 1.11-1.85), and high-frequency HL (AOR, 1.74; 95% CI, 1.29-2.34). When using the subjective HL tool and questioning regarding whether the participants were having troublesome hearing and/or tinnitus in screening for HL, the age- and gender-adjusted area under the curve was 0.88 in detecting speech-frequency HL and 0.90 in detecting high-frequency HL.

Conclusion and Relevance

The findings of this study suggest that cancer survivors have a significantly higher prevalence of HL than the general population. Two subjective HL questions could potentially accurately identify those who have true HL and provide a simple and efficient screening tool for health care professionals. Cancer survivors and their families should be educated and encouraged to discuss hearing concerns, and health care professionals should facilitate raising awareness and provide early screening and timely referral when HL is identified.

Molecular Characteristics of Cisplatin-Induced Ototoxicity and Therapeutic Interventions

Cisplatin is a commonly used chemotherapeutic agent with proven efficacy in treating various malignancies, including testicular, ovarian, cervical, breast, bladder, head and neck, and lung cancer. Cisplatin is also used to treat tumors in children, such as neuroblastoma, osteosarcoma, and hepatoblastoma. However, its clinical use is limited by severe side effects, including ototoxicity, nephrotoxicity, neurotoxicity, hepatotoxicity, gastrointestinal toxicity, and retinal toxicity. Cisplatin-induced ototoxicity manifests as irreversible, bilateral, high-frequency sensorineural hearing loss in 40-60% of adults and in up to 60% of children. Hearing loss can lead to social isolation, depression, and cognitive decline in adults, and speech and language developmental delays in children. Cisplatin causes hair cell death by forming DNA adducts, mitochondrial dysfunction, oxidative stress, and inflammation, culminating in programmed cell death by apoptosis, necroptosis, pyroptosis, or ferroptosis. Contemporary medical interventions for cisplatin ototoxicity are limited to prosthetic devices, such as hearing aids, but these have significant limitations because the cochlea remains damaged. Recently, the U.S. Food and Drug Administration (FDA) approved the first therapy, sodium thiosulfate, to prevent cisplatin-induced hearing loss in pediatric patients with localized, non-metastatic solid tumors. Other pharmacological treatments for cisplatin ototoxicity are in various stages of preclinical and clinical development. This narrative review aims to highlight the molecular mechanisms involved in cisplatin-induced ototoxicity, focusing on cochlear inflammation, and shed light on potential antioxidant and anti-inflammatory therapeutic interventions to prevent or mitigate the ototoxic effects of cisplatin. We conducted a comprehensive literature search (Google Scholar, PubMed) focusing on publications in the last five years.

Macrophage Depletion Protects Against Cisplatin-Induced Ototoxicity and Nephrotoxicity

Cisplatin is a widely used and highly effective anti-cancer drug with significant side effects including ototoxicity and nephrotoxicity. Macrophages, the major resident immune cells in the cochlea and kidney, are important drivers of both inflammatory and tissue repair responses. To investigate the roles of macrophages in cisplatin-induced ototoxicity and nephrotoxicity, we used PLX3397, an FDA-approved inhibitor of the colony-stimulating factor 1 receptor (CSF1R), to eliminate tissue-resident macrophages during the course of cisplatin administration. Mice treated with cisplatin alone (cisplatin/vehicle) had significant hearing loss (ototoxicity) as well as kidney injury (nephrotoxicity). Macrophage ablation using PLX3397 resulted in significantly reduced hearing loss measured by auditory brainstem responses (ABR) and distortion-product otoacoustic emissions (DPOAE). Sensory hair cells in the cochlea were protected against cisplatin-induced death in mice treated with PLX3397. Macrophage ablation also protected against cisplatin-induced nephrotoxicity, as evidenced by markedly reduced tubular injury and fibrosis as well as reduced plasma blood urea nitrogen (BUN) and neutrophil gelatinase-associated lipocalin (NGAL) levels. Mechanistically, our data suggest that the protective effect of macrophage ablation against cisplatin-induced ototoxicity and nephrotoxicity is mediated by reduced platinum accumulation in both the inner ear and the kidney. Together our data indicate that ablation of tissue-resident macrophages represents a novel strategy for mitigating cisplatin-induced ototoxicity and nephrotoxicity.

Brief summary

Macrophage ablation using PLX3397 was protective against cisplatin-induced ototoxicity and nephrotoxicity by limiting platinum accumulation in the inner ear and kidney.

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.

Overcoming barriers: a review on innovations in drug delivery to the middle and inner ear

Despite significant advances in the development of therapeutics for hearing loss, drug delivery to the middle and inner ear remains a challenge. As conventional oral or intravascular administration are ineffective due to poor bioavailability and impermeability of the blood-labyrinth-barrier, localized delivery is becoming a preferable approach for certain drugs. Even then, localized delivery to the ear precludes continual drug delivery due to the invasive and potentially traumatic procedures required to access the middle and inner ear. To address this, the preclinical development of controlled release therapeutics and drug delivery devices have greatly advanced, with some now showing promise clinically. This review will discuss the existing challenges in drug development for treating the most prevalent and damaging hearing disorders, in particular otitis media, perforation of the tympanic membrane, cholesteatoma and sensorineural hearing loss. We will then address novel developments in drug delivery that address these including novel controlled release therapeutics such as hydrogel and nanotechnology and finally, novel device delivery approaches such as microfluidic systems and cochlear prosthesis-mediated delivery. The aim of this review is to investigate how drugs can reach the middle and inner ear more efficiently and how recent innovations could be applied in aiding drug delivery in certain pathologic contexts.

Activation of Nrf2 inhibits ferroptosis and protects against oxaliplatin-induced ototoxicity

Oxaliplatin, as a third-generation platinum-based anticancer drug, is widely used in tumor therapy of many systems. Clinically, oxaliplatin has a number of serious side effects, most notably neuropathy and ototoxicity. The degeneration of cochlear hair cells is the main reason for the hearing loss caused by platinum-based drugs. However, the mechanism of oxaliplatin-induced cochlear hair cell death remains unclear. Ferroptosis is a novel cell injury pattern triggered by the accumulation of iron hydroperoxides in lipids and dependent on the participation of iron ions, which plays an important role in a variety of diseases. Whether ferroptosis is involved in oxaliplatin-induced ototoxicity has not been reported. In this study, we observed that oxaliplatin treatment resulted in lipid peroxidation and reactive oxygen species (ROS) accumulation in OC1 cells, which may be an early alteration in the occurrence of ferroptosis. Additional treatment with ferroptosis inducer or inhibitor significantly aggravated or ameliorated oxaliplatin-induced cytotoxicity. Similarly, inhibition of ferroptosis also protected cochlear hair cells against oxaliplatin-induced injury. In addition, the expression of nuclear factor erythroid 2-related factor2 (Nrf2) and heme oxygenase-1 (HO-1) was significantly increased after oxaliplatin treatment, and treatment with the Nrf2 agonist, resveratrol, dramatically attenuated cochlear hair cell damage induced by oxaliplatin. Activation of Nrf2 significantly decreased the expression of iron regulatory protein 2 (IRP-2) and reversed the expression of glutathione peroxidase 4 (GPX4). Collectively, our results demonstrated that activation of Nrf2 alleviates oxaliplatin-induced cochlear hair cell damage by inhibiting ferroptosis, which may be a new mechanism of oxaliplatin-induced ototoxicity.

Current status of sinonasal cancer survivorship care

Sinonasal cancer is a heterogeneous orphan disease of diverse histologies, each with distinct clinical, oncologic, and toxicity profiles. Because of the comparative rarity of these cancers, sinonasal cancers are treated as a grouped diagnosis despite their clinical and biological heterogeneity. Multimodality treatment with a combination of surgery, chemotherapy, and/or radiotherapy is the standard-of-care for advanced-stage patients but there are few surveillance or follow-up practice guidelines or formalized survivorship care pathways. A scoping literature review was conducted via PubMed, EMBASE, and Google Scholar. A total of 112 studies were included, which were grouped along the following topics: surveillance, second primary tumors, quality of life, and symptom burden. Sinonasal cancer tends to exhibit a higher rate of local failure and occur in a delayed fashion compared to mucosal malignancies of the head and neck. Moreover, the site of failure and time-varying risk of recurrence is histology-specific. Following multimodality treatment of the skull base, patients may experience endocrine, visual, auditory, sinonasal, olfactory, and neurocognitive deficits, as well as psychosocial impairments that impact multiple physical and neuropsychological domains, resulting in diminished quality of life. Sinonasal cancer patients would benefit from tailored, histology-specific survivorship programs to address the recurrence, second primary, and functional impairments resulting from disease and treatment toxicity.

Children's Oncology Group's 2023 blueprint for research: Germ cell tumors

Extracranial germ cell tumors (GCT) are a biologically diverse group of tumors occurring in children, adolescents, and young adults. The majority of patients have excellent outcomes, but treatment-related toxicities impact their quality of survivorship. A subset of patients succumbs to the disease. Current unmet needs include clarifying which patients can be safely observed after initial surgical resection, refinement of risk stratification to reduce chemotherapy burden in patients with standard-risk disease, and intensify therapy for patients with poor-risk disease. Furthermore, enhancing strategies for detection of minimal residual disease and early detection of relapse, particularly in serum tumor marker-negative histologies, is critical. Improving the understanding of the developmental and molecular origins of GCTs may facilitate discovery of novel targets. Future efforts should be directed toward assessing novel therapies in a biology-driven, biomarker-defined, histology-specific, risk-stratified patient population. Fragmentation of care between subspecialists restricts the unified study of these rare tumors. It is imperative that trials be conducted in collaboration with national and international cooperative groups, with harmonized data and biospecimen collection. Key priorities for the Children's Oncology Group (COG) GCT Committee include (a) better understanding the biology of GCTs, with a focus on molecular targets and mechanisms of treatment resistance; (b) strategic development of pediatric and young adult clinical trials; (c) understanding late effects of therapy and identifying individuals most at risk; and (d) prioritizing diversity, equity, and inclusion to reduce cancer health disparities and studying the impacts of social determinants of health on outcomes.

Cancer survivors and neurotoxic chemotherapy: hearing loss and tinnitus

OBJECTIVES

Little is known about hearing loss and tinnitus associated with neurotoxic chemotherapy. Study evaluated for differences in occurrence rates and effects of hearing loss and tinnitus in survivors who received a platinum alone, a taxane alone or a platinum and taxane containing regimen.

METHODS

Total of 273 survivors with breast, gastrointestinal, gynaecological or lung cancer completed self-report measures of hearing loss and tinnitus and had an audiometric assessment that obtained pure tone air conduction thresholds bilaterally at frequencies of between 0.25 kHz to 16.0 kHz. To adjust for age-related and gender-related changes in hearing, each survivor's audiogram was evaluated using the National Health and Nutrition Examination Survey-modified Occupational Safety and Health Administration standards. Survivor was classified as having hearing loss if at any frequency they scored poorer than the 50th percentile for their age and gender. Survivors were categorised as having tinnitus if they reported that for >10% of their time awake, they were consciously aware of their tinnitus. Differences among the chemotherapy groups were evaluated using parametric and non-parametric tests.

RESULTS

For most of the demographic and clinical characteristics, no differences were found among the three chemotherapy groups. Occurrence rates for audiogram-confirmed hearing loss ranged from 52.3% to 71.4%. Occurrence rates for tinnitus ranged from 37.1% to 40.0%. No differences were found among the three chemotherapy groups in the occurrence rates or effects of hearing loss and tinnitus.

CONCLUSION

These findings suggest that regardless of the chemotherapy regimen common mechanistic pathway(s) may underlie these two neurotoxicities.

Predicting Hearing Loss in Testicular Cancer Patients after Cisplatin-Based Chemotherapy

Testicular cancer is predominantly curable, but the long-term side effects of chemotherapy have a severe impact on life quality. In this research study, we focus on hearing loss as a part of overall chemotherapy-induced ototoxicity. This is a unique approach where we combine clinical data from the acclaimed nationwide Danish Testicular Cancer (DaTeCa)-Late database. Clinical and genetic data on 433 patients were collected from hospital files in October 2014. Hearing loss was classified according to the FACT/GOG-Ntx-11 version 4 self-reported Ntx6. Machine learning models combining a genome-wide association study within a nested cross-validated logistic regression were applied to identify patients at high risk of hearing loss. The model comprising clinical and genetic data identified 67% of the patients with hearing loss; however, this was with a false discovery rate of 49%. For the non-affected patients, the model identified 66% of the patients with a false omission rate of 19%. An area under the receiver operating characteristic (ROC-AUC) curve of 0.73 (95% CI, 0.71-0.74) was obtained, and the model suggests genes SOD2 and MGST3 as important in improving prediction over the clinical-only model with a ROC-AUC of 0.66 (95% CI, 0.65-0.66). Such prediction models may be used to allow earlier detection and prevention of hearing loss. We suggest a possible biological mechanism for cisplatin-induced hearing loss development. On confirmation in larger studies, such models can help balance treatment in clinical practice.

Kremen1 regulates the regenerative capacity of support cells and mechanosensory hair cells in the zebrafish lateral line

Mechanosensory hair cells in the inner ear mediate the sensations of hearing and balance, and in a specialize lateral line sensory system of aquatic vertebrates, the sensation of water movement. In mammals, hair cells lack the ability of regenerate following damage, resulting in sensory deficits. In contrast, non-mammalian vertebrates, such zebrafish, can renew hair cells throughout the life of the animal. Wnt signaling is required for development of inner ear and lateral line hair cells and regulates regeneration. Kremen1 inhibits Wnt signaling and hair cell formation, though its role in regeneration has not been established. We use a zebrafish kremen1 mutant line, to show that when Wnt signaling is overactivated in the lateral line, excessive regeneration occurs in the absence of increased proliferation, due to an increase in support cells. This contrasts with the previously described role of Wnt signaling during hair cell regeneration. This work will allow us to understand the biology of mechanosensory hair cells, and how regeneration might be promoted following damage.

Intravenous N-Acetylcysteine to Prevent Cisplatin-Induced Hearing Loss in Children: A Nonrandomized Controlled Phase I Trial

PURPOSE

Cisplatin-induced hearing loss (CIHL) is common and permanent. As compared with earlier otoprotectants, we hypothesized N-acetylcysteine (NAC) offers potential for stronger otoprotection through stimulation of glutathione (GSH) production. This study tested the optimal dose, safety, and efficacy of NAC to prevent CIHL.

PATIENTS AND METHODS

In this nonrandomized, controlled phase Ia/Ib trial, children and adolescents newly diagnosed with nonmetastatic, cisplatin-treated tumors received NAC intravenously 4 hours post-cisplatin. The trial performed dose-escalation across three dose levels to establish a safe dose that exceeded the targeted peak serum NAC concentration of 1.5 mmol/L (as identified from preclinical models). Patients with metastatic disease or who were otherwise ineligible were enrolled in an observation-only/control arm. To evaluate efficacy, serial age-appropriate audiology assessments were performed. Integrated biology examined genes involved in GSH metabolism and post-NAC GSH concentrations.

RESULTS

Of 52 patients enrolled, 24 received NAC and 28 were in the control arm. The maximum tolerated dose was not reached; analysis of peak NAC concentration identified 450 mg/kg as the recommended phase II dose (RP2D). Infusion-related reactions were common. No severe adverse events occurred. Compared with the control arm, NAC decreased likelihood of CIHL at the end of cisplatin therapy [OR, 0.13; 95% confidence interval (CI), 0.021-0.847; P = 0.033] and recommendations for hearing intervention at end of study (OR, 0.082; 95% CI, 0.011-0.60; P = 0.014). NAC increased GSH; GSTP1 influenced risk for CIHL and NAC otoprotection.

CONCLUSIONS

NAC was safe at the RP2D, with strong evidence for efficacy to prevent CIHL, warranting further development as a next-generation otoprotectant.

Patient-Reported Functional Impairment Due to Hearing Loss and Tinnitus After Cisplatin-Based Chemotherapy

PURPOSE

Cisplatin is widely used and highly ototoxic, but patient-reported functional impairment because of cisplatin-related hearing loss (HL) and tinnitus has not been comprehensively evaluated.

PATIENTS AND METHODS

Testicular cancer survivors (TCS) given first-line cisplatin-based chemotherapy completed validated questionnaires, including the Hearing Handicap Inventory for Adults (HHIA) and Tinnitus Primary Function Questionnaire (TPFQ), each of which quantifies toxicity-specific functional impairment. Spearman correlations evaluated associations between HL and tinnitus severity and level of functional handicap quantified with the HHIA and TPFQ, respectively. Associations between HL or tinnitus and five prespecified adverse health outcomes (cognitive dysfunction, fatigue, depression, anxiety, and overall health) were evaluated.

RESULTS

HL and tinnitus affected 137 (56.4%) and 147 (60.5%) of 243 TCS, respectively. Hearing aids were used by 10% TCS (14/137). Of TCS with HL, 35.8% reported clinically significant functional impairment. Severe HHIA-assessed functional impairment was associated with cognitive dysfunction (odds ratio [OR], 10.62; P < .001), fatigue (OR, 5.48; P = .003), and worse overall health (OR, 0.19; P = .012). Significant relationships existed between HL severity and HHIA score, and tinnitus severity and TPFQ score (P < .0001 each). TCS with either greater hearing difficulty or more severe tinnitus were more likely to report cognitive dysfunction (OR, 5.52; P = .002; and OR, 2.56; P = .05), fatigue (OR, 6.18; P < .001; and OR, 4.04; P < .001), depression (OR, 3.93; P < .01; and OR, 3.83; P < .01), and lower overall health (OR, 0.39; P = .03; and OR, 0.46; P = .02, respectively).

CONCLUSION

One in three TCS with HL report clinically significant functional impairment. Follow-up of cisplatin-treated survivors should include routine assessment for HL and tinnitus. Use of the HHIA and TPFQ permit risk stratification and referral to audiologists as needed, since HL adversely affects functional status and is the single largest modifiable risk factor for cognitive decline and dementia in the general population.

SIRT3/GLUT4 signaling activation by metformin protect against cisplatin-induced ototoxicity in vitro

Cisplatin is highly effective for killing tumor cells. However, as one of its side effects, ototoxicity limits the clinical application of cisplatin. The mechanisms of cisplatin-induced ototoxicity have not been fully clarified yet. SIRT3 is a deacetylated protein mainly located in mitochondria, which regulates a variety of physiological processes in cells. The role of SIRT3 in cisplatin-induced hair cell injury has not been founded. In this study, primary cultured cochlear explants exposed to 5 μM cisplatin, as well as OC-1 cells exposed to 10 μM cisplatin, were used to establish models of cisplatin-induced ototoxicity in vitro. We found that when combined with cisplatin, metformin (75 μM) significantly up-regulated the expression of SIRT3 and alleviated cisplatin-induced apoptosis of hair cells. We regulated the expression of SIRT3 to explore the role of SIRT3 in cisplatin-induced auditory hair cell injury. Overexpression of SIRT3 promoted the survival of auditory hair cells and alleviated the apoptosis of auditory hair cells. In contrast, knockdown of SIRT3 impaired the protective effect of metformin and exacerbated cisplatin injury. In addition, we found that the protective effect of SIRT3 may be achieved by regulating GLUT4 translocation and rescuing impaired glucose uptake caused by cisplatin. Our study confirmed that upregulation of SIRT3 may antagonize cisplatin-induced ototoxicity, and provided a new perspective for the study of cisplatin-induced ototoxicity.

Association of Clinical Aspects and Genetic Variants with the Severity of Cisplatin-Induced Ototoxicity in Head and Neck Squamous Cell Carcinoma: A Prospective Cohort Study

Background: Cisplatin (CDDP) is a major ototoxic chemotherapy agent for head and neck squamous cell carcinoma (HNSCC) treatment. Clinicopathological features and genotypes encode different stages of CDDP metabolism, as their coexistence may influence the prevalence and severity of hearing loss. Methods: HNSCC patients under CDDP chemoradiation were prospectively provided with baseline and post-treatment audiometry. Clinicopathological features and genetic variants encoding glutathione S-transferases (GSTT1, GSTM1, GSTP1), nucleotide excision repair (XPC, XPD, XPF, ERCC1), mismatch repair (MLH1, MSH2, MSH3, EXO1), and apoptosis (P53, CASP8, CASP9, CASP3, FAS, FASL)-related proteins were analyzed regarding ototoxicity. Results: Eighty-nine patients were included, with a cumulative CDDP dose of 260 mg/m2. Moderate/severe ototoxicity occurred in 26 (29%) patients, particularly related to hearing loss at frequencies over 3000 Hertz. Race, body-mass index, and cumulative CDDP were independent risk factors. Patients with specific isolated and combined genotypes of GSTM1, GSTP1 c.313A>G, XPC c.2815A>C, XPD c.934G>A, EXO1 c.1762G>A, MSH3 c.3133A>G, FASL c.-844A>T, and P53 c.215G>C SNVs had up to 32.22 higher odds of presenting moderate/severe ototoxicity. Conclusions: Our data present, for the first time, the association of combined inherited nucleotide variants involved in CDDP efflux, DNA repair, and apoptosis with ototoxicity, which could be potential predictors in future clinical and genomic models.

Role of Cisplatin Dose Intensity and TPMT Variation in the Development of Hearing Loss in Children

BACKGROUND

Cisplatin, widely used in the treatment of solid tumors, causes permanent hearing loss in more than 60% of treated children. Previous studies have implicated several clinical factors in the development of ototoxicity, including cumulative cisplatin dose. However, the role of cisplatin dose intensity in the development of hearing loss in children remains unclear. Pharmacogenetic studies have also identified genetic variants in TPMT that increase the risk of cisplatin-induced hearing loss. This study aims to determine whether cisplatin dose intensity contributes to the risk of hearing loss in children and whether genetic variations in TPMT further modifies the risk of cisplatin-induced hearing loss.

METHODS

The authors genotyped 371 cisplatin-treated children for the presence of any 3 TPMT-risk variants. Patients were categorized into high-, moderate-, and low-intensity cisplatin dosing groups according to the cisplatin dose administered per unit time. Kaplan-Meier curves were plotted to compare the cumulative incidence of hearing loss between the genotype and dose intensity groups.

RESULTS

Patients receiving cisplatin at high dose intensity experienced significantly higher incidences of ototoxicity than those receiving cisplatin at low dose intensity (P = 9 × 10-7). Further stratification by TPMT genotype revealed that carriers of ≥1 TPMT variants receiving high-intensity cisplatin developed ototoxicity sooner and more often than their wild-type counterparts (93.8% vs. 56.6% at 12 months; P = 5 × 10-5) and noncarriers receiving low-intensity cisplatin (21.2% at 12 months).

CONCLUSIONS

Cisplatin dose intensity is strongly associated with ototoxicity development in children, and this risk is further increased by the presence of TPMT-risk alleles.

Aucubin protects mouse cochlear hair cells from cisplatin-induced ototoxicity via activation of the PI3K/AKT/STAT3 pathway

Cisplatin is commonly used to treat cancers and is associated with a significant risk of irreversible sensorineural hearing loss. However, no effective preventive strategies are available for cisplatin-induced HL. Therefore, significant efforts have been made to discover new drugs protecting cochlear hair cells from cisplatin-induced damage. We found that a new phytochemical, aucubin, attenuated cisplatin-induced apoptosis, the production of reactive oxygen species, and mitochondrial dysfunction in House Ear Institute Organ of Corti 1 cells and cochlear hair cells. Moreover, aucubin attenuated cisplatin-induced sensorineural hearing loss and hair cells loss in vivo. Furthermore, RNA sequencing analysis revealed that the otoprotective effects of aucubin were mainly mediated by increased STAT3 phosphorylation via the PI3K/AKT pathway. Inhibition of the STAT3 signaling pathway with the inhibitor S3I-201 or siRNA disrupted the protective effects of aucubin on cisplatin-induced apoptosis. In conclusion, we identified an otoprotective effect of aucubin. Therefore, aucubin could be used to prevent cisplatin-induced ototoxicity.

Future Pharmacotherapy for Sensorineural Hearing Loss by Protection and Regeneration of Auditory Hair Cells

Sensorineural hearing loss has been a global burden of diseases for decades. However, according to recent progress in experimental studies on hair cell regeneration and protection, clinical trials of pharmacotherapy for sensorineural hearing loss have rapidly progressed. In this review, we focus on recent clinical trials for hair cell protection and regeneration and outline mechanisms based on associated experimental studies. Outcomes of recent clinical trials provided valuable data regarding the safety and tolerability of intra-cochlear and intra-tympanic applications as drug delivery methods. Recent findings in molecular mechanisms of hair cell regeneration suggested the realization of regenerative medicine for sensorineural hearing loss in the near future.

Special considerations in the design and implementation of pediatric otoprotection trials

PURPOSE

Cisplatin-induced hearing loss (CIHL) is a common late effect after childhood cancer treatment having profound, lifelong consequences that lower quality of life. The recent identification of intravenous sodium thiosulfate (STS) as an effective agent for preventing pediatric CIHL represents a paradigm shift that has created new opportunities for expanding STS usage and developing additional otoprotectants. The purpose of this paper is to discuss key considerations and recommendations for the design and implementation of future pediatric otoprotection trials.

METHODS

An approach synthesizing published data and collective experience was used.

RESULTS

Key issues were identified in the categories of translational research, trial designs for systemic and intratympanic agents, measurement of ototoxicity, and biostatistical challenges.

CONCLUSIONS

Future pediatric otoprotection trials should emphasize (1) deep integration of preclinical and early-phase studies; (2) an embedded or free-standing design for systemic agents based on mechanistic considerations; (3) use of suitable audiologic testing batteries for children, SIOP grading criteria, and submission of raw audiologic data for central review; and (4) novel endpoints and innovative study designs that maximize trial efficiency for limited sample sizes. Additional recommendations include routine collection of DNA specimens for assessing modifying effects of genetic susceptibility and meaningful inclusion of patient/family advocates for informing trial development.

IMPLICATIONS FOR CANCER SURVIVORS

Changing the historical paradigm from acceptance to prevention of pediatric CIHL through expanded research with existing and emerging otoprotectants will dramatically improve quality of life for future childhood cancer survivors exposed to cisplatin.

Prevalence and risk factors for ototoxicity after cisplatin-based chemotherapy

PURPOSE

Ototoxicity is a prominent side effect of cisplatin-based chemotherapy. There are few reports, however, estimating its prevalence in well-defined cohorts and associated risk factors.

METHODS

Testicular cancer (TC) survivors given first-line cisplatin-based chemotherapy completed validated questionnaires. Descriptive statistics evaluated the prevalence of ototoxicity, defined as self-reported hearing loss and/or tinnitus. We compared patients with and without tinnitus or hearing loss using Chi-square test, two-sided Fisher's exact test, or two-sided Wilcoxon rank sum test. To evaluate ototoxicity risk factors, a backward selection logistic regression procedure was performed.

RESULTS

Of 145 TC survivors, 74% reported ototoxicity: 68% tinnitus; 59% hearing loss; and 52% reported both. TC survivors with tinnitus were more likely to indicate hypercholesterolemia (P = 0.008), and difficulty hearing (P < .001). Tinnitus was also significantly related to age at survey completion (OR = 1.79; P = 0.003) and cumulative cisplatin dose (OR = 5.17; P < 0.001). TC survivors with hearing loss were more likely to report diabetes (P = 0.042), hypertension (P = 0.007), hypercholesterolemia (P < 0.001), and family history of hearing loss (P = 0.044). Risk factors for hearing loss included age at survey completion (OR = 1.57; P = 0.036), hypercholesterolemia (OR = 3.45; P = 0.007), cumulative cisplatin dose (OR = 1.94; P = 0.049), and family history of hearing loss (OR = 2.87; P = 0.071).

CONCLUSIONS

Ototoxicity risk factors included age, cisplatin dose, cardiovascular risk factors, and family history of hearing loss. Three of four TC survivors report some type of ototoxicity; thus, follow-up of cisplatin-treated survivors should include routine assessment for ototoxicity with provision of indicated treatments.

IMPLICATIONS FOR CANCER SURVIVORS

Survivors should be aware of risk factors associated with ototoxicity. Referrals to audiologists before, during, and after cisplatin treatment is recommended.

Balancing efficacy with long-term side-effects: can we safely de-escalate therapy for germ cell tumors?

INTRODUCTION

The success in the management of germ cell tumors has encouraged researchers to pay more attention on long-term side effects and other survivorship issues. The de-escalation of treatment is intended to reduce side effects but must be balanced against any compromise of efficacy. Cisplatin-based therapy is the cornerstone of treatment for germ cell tumors. However, they can result in acute and long-term side effects, including ototoxicity, neurotoxicity, nephrotoxicity, and increased risk of second malignancies.

AREAS COVERED

This review discusses approaches of de-escalation including biomarker-directed treatment using microRNAs, surveillance for immature teratoma, the use of carboplatin monotherapy for seminoma, and the option of non-cisplatin-based approaches in relapsed germ cell tumors.

EXPERT OPINION

While the results with the current standard options in terms of cancer control are very good, the price being paid in terms of long-term side effects is considerable.

Comprehensive association analysis of speech recognition thresholds after cisplatin-based chemotherapy in survivors of adult-onset cancer

PURPOSE

Deficits in speech understanding constitute one of the most severe consequences of hearing loss. Here we investigate the clinical and genetic risk factors for symmetric deterioration of speech recognition thresholds (SRT) among cancer survivors treated with cisplatin.

METHODS

SRT was measured using spondaic words and calculating the mean of measurements for both ears with symmetric SRT values. For clinical associations, SRT-based hearing disability (SHD) was defined as SRT≥15 dB hearing loss and clinical variables were derived from the study dataset. Genotyped blood samples were used for GWAS with rank-based inverse normal transformed SRT values as the response variable. Age was used as a covariate in association analyses.

RESULTS

SHD was inversely associated with self-reported health (p = 0.004). Current smoking (p = 0.002), years of smoking (p = 0.02), BMI (p < 0.001), and peripheral motor neuropathy (p = 0.003) were positively associated with SHD, while physical activity was inversely associated with SHD (p = 0.005). In contrast, cumulative cisplatin dose, peripheral sensory neuropathy, hypertension, and hypercholesterolemia were not associated with SHD. Although no genetic variants had an association p value < 5 × 10-8 , 22 genetic variants were suggestively associated (p < 10-5 ) with SRT deterioration. Three of the top variants in 10 respective linkage disequilibrium regions were either positioned within the coding sequence or were eQTLs for genes involved in neuronal development (ATE1, ENAH, and ZFHX3).

CONCLUSION

Current results improve our understanding of risk factors for SRT deterioration in cancer survivors. Higher BMI, lower physical activity, and smoking are associated with SHD. Larger samples would allow for expansion of the current findings on the genetic architecture of SRT.

Associations among hearing loss, multiple co-occurring symptoms, and quality of life outcomes in cancer survivors

PURPOSE

Evaluate for differences in demographic and clinical characteristics, occurrence of common symptoms, symptom severity scores, and quality of life (QOL) outcomes in survivors with (n = 155) and without (n = 118) audiometrically confirmed hearing loss.

METHODS

Survivors, who were recruited from throughout the San Francisco Bay area, completed the self-report questionnaires to obtain the information of demographic and clinical characteristics; the occurrence and severity of depression, anxiety, fatigue, decrements in energy, sleep disturbance, pain, and cognitive impairment; and the general and cancer-specific QOL outcomes. Parametric and non-parametric tests were used to evaluate for differences between the two survivor groups.

RESULTS

Survivors with audiometrically confirmed hearing loss were older, more likely to be male, were more likely to be unemployed, report a lower annual household income, and had a higher comorbidity burden. Except for the severity of worst pain, no between-group differences were found in the occurrence rates for or severity of any of the symptoms. Survivors with hearing loss reported worse physical function and general health scores.

CONCLUSIONS

While no between-group differences in symptom occurrence rates and severity scores were found, across the total sample, a relatively high percentage of survivors who were over 6 years from their cancer diagnosis reported clinically meaningful levels of depression (25%), anxiety (50%), fatigue (40%), decrements in energy (70%), sleep disturbance (58%), cognitive impairment (57%), and pain (60%).

IMPLICATIONS FOR CANCER SURVIVORS

Clinicians need to perform routine assessments of hearing loss, as well as common co-occurring symptoms and initiate individualized symptom management interventions.

Audiologists' perceived value of ototoxicity management and barriers to implementation for at-risk cancer patients in VA: the OtoMIC survey

PURPOSE

Platinum-based chemotherapies used to treat many types of cancers are ototoxic. Ototoxicity management (OtoM) to mitigate the ototoxic outcomes of cancer survivors is recommended practice yet it is not a standard part of oncologic care. Although more than 10,000 patients each year are treated with platinum-based chemotherapies at the US Veterans Health Administration (VA), the current state of OtoM in VA is not well-defined. This study reports on a national survey of VA audiologists' perceptions regarding OtoM in cancer patients.

METHODS

A 26-item online survey was administered to VA audiologists and service chiefs across the VA's 18 regional systems of care. Descriptive statistics and deductive thematic analysis were used to analyze the data.

RESULTS

The 61 respondents included at least one from each VA region. All reported they felt some form of OtoM was necessary for at-risk cancer patients. A pre-treatment baseline, the ability to detect ototoxicity early, and management of ototoxic effects both during and after treatment were considered high value objectives of OtoM by respondents. Roughly half reported routinely providing these services for patients receiving cisplatin and carboplatin. Respondents disagreed regarding appropriate hearing testing schedules and how to co-manage OtoM responsibilities with oncology. They identified barriers to care that conformed to three themes: care and referral coordination with oncology, audiology workload, and lack of protocols.

CONCLUSIONS

Although VA audiologists value providing OtoM for cancer patients, only about half perform OtoM for highly ototoxic treatment regimens. The OtoMIC survey provides clinician perspectives to benchmark and address OtoM care gaps.

IMPLICATIONS FOR CANCER SURVIVORS

Collaboration between oncology and audiology is needed to improve current OtoM processes, so that cancer survivors can have more control over their long term hearing health.

Ototoxicity prognostic models in adult and pediatric cancer patients: a rapid review

PURPOSE

A cornerstone of treatment for many cancers is the administration of platinum-based chemotherapies and/or ionizing radiation, which can be ototoxic. An accurate ototoxicity risk assessment would be useful for counseling, treatment planning, and survivorship follow-up in patients with cancer.

METHODS

This systematic review evaluated the literature on predictive models for estimating a patient's risk for chemotherapy-related auditory injury to accelerate development of computational approaches for the clinical management of ototoxicity in cancer patients. Of the 1195 articles identified in a PubMed search from 2010 forward, 15 studies met inclusion for the review.

CONCLUSIONS

All but 1 study used an abstraction of the audiogram as a modeled outcome; however, specific outcome measures varied. Consistently used predictors were age, baseline hearing, cumulative cisplatin dose, and radiation dose to the cochlea. Just 5 studies were judged to have an overall low risk of bias. Future studies should attempt to minimize bias by following statistical best practices including not selecting multivariate predictors based on univariate analysis, validation in independent cohorts, and clearly reporting the management of missing and censored data. Future modeling efforts should adopt a transdisciplinary approach to define a unified set of clinical, treatment, and/or genetic risk factors. Creating a flexible model that uses a common set of predictors to forecast the full post-treatment audiogram may accelerate work in this area. Such a model could be adapted for use in counseling, treatment planning, and follow-up by audiologists and oncologists and could be incorporated into ototoxicity genetic association studies as well as clinical trials investigating otoprotective agents.

IMPLICATIONS FOR CANCER SURVIVORS

Improvements in the ability to model post-treatment hearing loss can help to improve patient quality of life following cancer care. The improvements advocated for in this review should allow for the acceleration of advancements in modeling the auditory impact of these treatments to support treatment planning and patient counseling during and after care.

Prevalence of Tinnitus and Its Associated Factors in the PERSIAN Guilan Cohort Study

Introduction

Tinnitus can be associated with many auditory and non-auditory factors, and its prevalence varies widely in the literature. There is no large sample of published data on tinnitus prevalence and its associated factors in Iran. Here, we analyzed the PERSIAN Guilan Cohort Study (PGCS) data and reported the prevalence of tinnitus and some of the risk factors related to tinnitus in the Iranian population.

Materials and Methods

This cross-sectional study was conducted on 10520 men and women between 35 and 70 years old. The prevalence of tinnitus and associations between tinnitus and age, sex, habitat, marital status, employment status, socioeconomic status, educational level, lifestyle habits, and comorbid diseases were examined using simple and multiple logistic regression analyses.

Results

The prevalence of tinnitus was 6.4% in this study. Based on the adjusted analysis, only older age (odds ratio: 2.60, 95% confidence interval: 1.88 - 3.60), residency in a rural area (odds ratio: 1.22, 95% confidence interval: 1.03 - 1.44), cigarette smoking (odds ratio:1.33, 95% confidence interval: 1.04 - 1.72), and having other comorbidities (odds ratio: 2.75, 95% confidence interval: 2.19 - 3.44) were related to tinnitus. In addition, the results of subgroup analyses by sex were mostly consistent with the overall analysis.

Conclusions

Our results revealed that the prevalence of tinnitus in the north of Iran is comparable with other communities. Age and other comorbidities were among the most related factors to tinnitus.

Evaluation and Management of Tinnitus: Are There Opportunities for Improvement?

OBJECTIVE

To review current information about diagnosis and management of tinnitus aiming to identify opportunities for achieving a cost-effective, efficient, evidence-based approach that meets the needs of tinnitus sufferers.

DATA SOURCES

PubMed/MEDLINE.

REVIEW METHODS

In total, 249 relevant published reports were reviewed. Pertinent keywords and MeSH terms identified reports via PubMed and EMBASE. Acknowledged experts were consulted on ways to improve tinnitus management.

CONCLUSIONS

There may be opportunities to improve evaluation and management of patients with tinnitus using modern modes of communication and a multidisciplinary therapeutic approach.

IMPLICATIONS FOR PRACTICE

Tinnitus can adversely affect quality of life while being time-consuming and costly to evaluate and manage. Based on both personal experience and the reports of others, patients with tinnitus who choose to see a physician primarily want to know two things: (1) that the tinnitus that is so distressing will not remain at the same level of severity forever and (2) that something can be done to help cope with the tinnitus that is so annoying. Recent advancements in internet communications, social media, information technology, artificial intelligence, machine learning, holistic medical care, mind-body integrative health care, and multidisciplinary approaches in medical therapeutics may be possibly making new ways of meeting the needs of patients with tinnitus.

Cisplatin-induced ototoxicity: From signaling network to therapeutic targets

Administration of cisplatin, a common chemotherapeutic drug, has an inevitable side effect of sensorineural hearing loss. The main etiologies are stria vascularis injury, spiral ganglion degeneration, and hair cell death. Over several decades, the research scope of cisplatin-induced ototoxicity has expanded with the discovery of the molecular mechanism mediating inner ear cell death, highlighting the roles of reactive oxygen species and transport channels for cisplatin uptake into inner ear cells. Upon entering hair cells, cisplatin disrupts organelle metabolism, induces oxidative stress, and targets DNA to cause intracellular damage. Recent studies have also reported the role of inflammation in cisplatin-induced ototoxicity. In this article, we preform a narrative review of the latest reported molecular mechanisms of cisplatin-induced ototoxicity, from extracellular to intracellular. We build up a signaling network starting with cisplatin entering into the inner ear through the blood labyrinth barrier, disrupting cochlear endolymph homeostasis, and activating inflammatory responses of the outer hair cells. After entering the hair cells, cisplatin causes hair cell death via DNA damage, redox system imbalance, and mitochondrial and endoplasmic reticulum dysfunction, culminating in programmed cell death including apoptosis, necroptosis, autophagic death, pyroptosis, and ferroptosis. Based on the mentioned mechanisms, prominent therapeutic targets, such as channel-blocking drugs of cisplatin transporter, construction of cisplatin structural analogues, anti-inflammatory drugs, antioxidants, cell death inhibitors, and others, were collated. Considering the recent research efforts, we have analyzed the feasibility of the aforementioned therapeutic strategies and proposed our otoprotective approaches to overcome cisplatin-induced ototoxicity.

A review of effects of atorvastatin in cancer therapy

Cancer is one of the most challenging diseases to manage. A sizeable number of researches are done each year to find better diagnostic and therapeutic strategies. At the present time, a package of chemotherapy, targeted therapy, radiotherapy, and immunotherapy is available to cope with cancer cells. Regarding chemo-radiation therapy, low effectiveness and normal tissue toxicity are like barriers against optimal response. To remedy the situation, some agents have been proposed as adjuvants to improve tumor responses. Statins, the known substances for reducing lipid, have shown a considerable capability for cancer treatment. Among them, atorvastatin as a reductase (HMG-CoA) inhibitor might affect proliferation, migration, and survival of cancer cells. Since finding an appropriate adjutant is of great importance, numerous studies have been conducted to precisely unveil antitumor effects of atorvastatin and its associated pathways. In this review, we aim to comprehensively review the most highlighted studies which focus on the use of atorvastatin in cancer therapy.

Evaluation of Cisplatin-Induced Pathology in the Larval Zebrafish Lateral Line

Cisplatin is an effective anticancer agent, but also causes permanent hearing loss by damaging hair cells-the sensory receptors essential for hearing. There is an urgent clinical need to protect cochlear hair cells in patients undergoing cisplatin chemotherapy. The zebrafish lateral line organ contains hair cells and has been frequently used in studies to screen for otoprotective compounds. However, these studies have employed a wide range of cisplatin dosages and exposure times. We therefore performed a comprehensive evaluation of cisplatin ototoxicity in the zebrafish lateral line with the goal of producing a standardized, clinically relevant protocol for future studies. To define the dose- and time-response patterns of cisplatin-induced hair-cell death, we treated 6-day-old larvae for 2 h in 50 µM-1 mM cisplatin and allowed them to recover. We observed delayed hair cell death, which peaked at 4-8 h post-exposure. Cisplatin also activated a robust inflammatory response, as determined by macrophage recruitment and phagocytosis of hair cells. However, selective depletion of macrophages did not affect hair cell loss. We also examined the effect of cisplatin treatment on fish behavior and found that cisplatin-induced lateral line injury measurably impaired rheotaxis. Finally, we examined the function of remaining hair cells that appeared resistant to cisplatin treatment. We observed significantly reduced uptake of the cationic dye FM1-43 in these cells relative to untreated controls, indicating that surviving hair cells may be functionally impaired. Cumulatively, these results indicate that relatively brief exposures to cisplatin can produce hair cell damage and delayed hair cell death. Our observations provide guidance on standardizing methods for the use of the zebrafish model in studies of cisplatin ototoxicity.

Platinum-induced ototoxicity in pediatric cancer survivors: GSTP1 c.313A>G variant association

Hearing damage is one of the main toxic effects of platinum compounds, it derives from the irreversible degeneration of hair cells of the ear. Genetic association studies have suggested an association between GSTP1 c.313A>G variant and platinum-induced ototoxicity in childhood cancer survivors. We aimed to detect the frequency of ototoxicity and associated risk factors in survivors of childhood cancer receiving platinum-based chemotherapy and to detect the relation between GSTP1 c.313A>G (rs1695) polymorphisms and ototoxicity. We conducted a cross-sectional study on 64 cancer survivors who received platinum agents (cisplatin and/or carboplatin) at least 2 years after the end of chemotherapy. The patients underwent comprehensive audiological evaluations and genotyping to detect the presence of the GSTP1 c.313A>G polymorphisms. Hearing loss (HL) was identified in 16/64 patients (25%), including 62.5% treated with cisplatin and 37.5% treated with carboplatin. The greater incidence of ototoxicity was found in children treated for osteosarcoma (28.1%) followed by patients with germ cell tumors (25%) and neuroblastoma (21.9%). The AA, AG, and GG types of GSTP1 c.313A>G variant were detected in 84.4%, 9.4%, and 6.3%, respectively, of patients with HL with a significant association between mutant genotype of GSTP1 rs1695 and platinum-induced ototoxicity (P = .035). HL was not significantly associated with the total cumulative dose of cisplatin and carboplatin. GSTP1 c.313A>G variant may increase the risk of HL in pediatric oncology patients treated with cisplatin or carboplatin chemotherapy.

Integrated Molecular Analysis Reveals 2 Distinct Subtypes of Pure Seminoma of the Testis

Objective:

Testicular germ cell tumors (TGCT) are the most common solid malignancy in adolescent and young men, with a rising incidence over the past 20 years. Overall, TGCTs are second in terms of the average life years lost per person dying of cancer, and clinical therapeutics without adverse long-term side effects are lacking. Platinum-based regimens for TGCTs have heterogeneous outcomes even within the same histotype that frequently leads to under- and over-treatment. Understanding of molecular differences that lead to diverse outcomes of TGCT patients may improve current treatment approaches. Seminoma is the most common subtype of TGCTs, which can either be pure or present in combination with other histotypes.

Methods:

Here we conducted a computational study of 64 pure seminoma samples from The Cancer Genome Atlas, applied consensus clustering approach to their transcriptomic data and revealed 2 clinically relevant seminoma subtypes: seminoma subtype 1 and 2.

Results:

Our analysis identified significant differences in pluripotency stage, activity of double stranded DNA breaks repair mechanisms, rates of loss of heterozygosity, and expression of lncRNA responsible for cisplatin resistance between the subtypes. Seminoma subtype 1 is characterized by higher pluripotency state, while subtype 2 showed attributes of reprograming into non-seminomatous TGCT. The seminoma subtypes we identified may provide a molecular underpinning for variable responses to chemotherapy and radiation.

Conclusion:

Translating our findings into clinical care may help improve risk stratification of seminoma, decrease overtreatment rates, and increase long-term quality of life for TGCT survivors.

Prospective Observational Study of Evaluating Cisplatin-Induced Ototoxicity in Patients

Introduction Platinum-based chemotherapeutic agents cisplatin and carboplatin are two of the most widely used drugs in cancer today. They display wide range of adverse reactions; among them, ototoxicity is an important cumulative toxicity that more commonly observed with cisplatin. At a later stage, it can affect speech of individual and lead to communication problem with decreased cognitive function and depression in cancer survivors. Periodic monitoring of hearing loss with pure-tone audiometry (PTA) provides early evidence of ototoxicity which may decrease debilitating effect of the same in a patient.

Objective The primary objective of this study was to assess cisplatin-induced ototoxicity. We also investigated its severity, reversibility, and other modifying risk factors.

Materials and Methods We conducted a prospective observational descriptive type of epidemiological study. The study was conducted over 80 randomly selected cancer patients (for estimation of sample size, the following formula was used n = [Zα 2 PQ] / d 2), who were starting with their first cycle of cisplatin from August 2018 to July 2020. This study was conducted at tertiary cancer care center in western Gujarat which caters patients from all over India. We performed PTA in all randomized patients at baseline and periodically. We classified hearing loss according to the World Health Organization (WHO) criteria.

Results A total of 30% (n = 24) patients developed cisplatin-induced ototoxicity according to WHO criteria at end of 3 months after starting the first cycle of cisplatin. It was sensory neuronal, affecting both the ears equally, and was seen predominantly at high frequency. We observed hearing loss at 3 months to be significantly more common in the 301 to 400 mg/m2 cumulative dose group (47%), as compared with the other two groups (0–200 mg/m2 and 201–300 mg/m2; p < 0.05). It showed dose dependency with cisplatin. In the multivariate step-wise regression model, baseline hearing loss (odds ratio [OR] = 17.71, 95% confidence interval [CI]: 6.57–118.91, p < 0.05) and cumulative cisplatin dose of more than 300 mg/m2 were significantly associated with hearing loss at 3 months (OR = 6.62, 95% CI: 2.33–18.74, p < 0.05).

Conclusion Cisplatin-induced ototoxicity manifests as a bilateral high frequency sensorineural hearing loss. Cumulative dose of cisplatin is an important predictor of development of ototoxicity. Baseline and periodic audiometric monitoring could detect ototoxicity early which leads to possible limitation on the severity of ototoxicity.