Ototoxicity from high-dose use of platinum compounds in patients with neuroblastoma

Ototoxicity and cancer therapy

Ototoxicity is a well-established toxicity associated with a subgroup of antineoplastic therapies that includes platinum chemotherapy, radiation or surgery involving the ear and auditory nerve, and supportive care agents such as aminoglycoside antibiotics and loop diuretics. The reported prevalence of ototoxicity in patients who have received potentially ototoxic therapy ranges from 4% to 90% depending on factors such as age of the patient population, agent(s) used, cumulative dose, and administration techniques. The impact of ototoxicity on subsequent health-related and psychosocial outcomes in these patients can be substantial, and the burden of morbidity related to ototoxic agents is particularly high in very young children. Considerable interindividual variability in the prevalence and severity of ototoxicity has been observed among patients receiving similar treatment, suggesting genetic susceptibility as a risk factor. The development and testing of otoprotective agents is ongoing; however, to the author's knowledge, no US Food and Drug Administration-approved otoprotectants are currently available. Prospective monitoring for ototoxicity allows for comparison of auditory outcomes across clinical trials, as well as for early detection, potential alterations in therapy, and auditory intervention and rehabilitation to ameliorate the adverse consequences of hearing loss. Cancer 2016;122:1647-58. © 2016 American Cancer Society.

Late Effects of Treatment of Pediatric Central Nervous System Tumors

Central nervous system tumors represent the most common solid malignancy in childhood. Improvement in treatment approaches have led to a significant increase in survival rates, with over 70% of children now surviving beyond 5 years. As more and more children with CNS tumors have longer survival times, it is important to be aware of the long-term morbidities caused not only by the tumor itself but also by tumor treatment. The most common side effects including poor neurocognition, endocrine dysfunction, neurological and vascular late effects, as well as secondary malignancies, are discussed within this article.

Cisplatin-Induced Ototoxicity: Effects, Mechanisms and Protection Strategies

Cisplatin is a highly effective chemotherapeutic agent that is widely used to treat solid organ malignancies. However, serious side effects have been associated with its use, such as bilateral, progressive, irreversible, dose-dependent neurosensory hearing loss. Current evidence indicates that cisplatin triggers the production of reactive oxygen species in target tissues in the inner ear. A variety of agents that protect against cisplatin-induced ototoxicity have been successfully tested in cell culture and animal models. However, many of them interfere with the therapeutic effect of cisplatin, and therefore are not suitable for systemic administration in clinical practice. Consequently, local administration strategies, namely intratympanic administration, have been developed to achieve otoprotection, without reducing the antitumoral effect of cisplatin. While a considerable amount of pre-clinical information is available, clinical data on treatments to prevent cisplatin ototoxicity are only just beginning to appear. This review summarizes clinical and experimental studies of cisplatin ototoxicity, and focuses on understanding its toxicity mechanisms, clinical repercussions and prevention strategies.

Common variants in ACYP2 influence susceptibility to cisplatin-induced hearing loss

Taking a genome-wide association study approach, we identified inherited genetic variations in ACYP2 associated with cisplatin-related ototoxicity (rs1872328: P = 3.9 × 10(-8), hazard ratio = 4.5) in 238 children with newly diagnosed brain tumors, with independent replication in 68 similarly treated children. The ACYP2 risk variant strongly predisposed these patients to precipitous hearing loss and was related to ototoxicity severity. These results point to new biology underlying the ototoxic effects of platinum agents.

Incidence of platinum-induced ototoxicity in pediatric patients in Quebec

BACKGROUND

The antineoplastic agents cisplatin and carboplatin are widely-used and highly-effective against a variety of pediatric cancers. Unfortunately, ototoxicity is a frequently encountered side effect of platinum-based chemotherapy. There is currently no treatment or prevention for platinum-induced ototoxicity and development of hearing loss may lead to devastating consequences on the quality of life of pediatric cancer survivors. The objective of this study is to determine the incidence of platinum-induced ototoxicity in a large series of pediatric patients and to evaluate the incidence of progression of ototoxicity after completion of treatment.

PROCEDURES

A retrospective chart review of pediatric patients treated with cisplatin or carboplatin between 2000 and 2012 was conducted. The incidence of ototoxicity was determined based on the American-Speech-Language-Hearing Association (ASHA) criteria and severity was based on the Chang classification.

RESULTS

Four hundred and sixty-six patients received platinum-based chemotherapy. Patients were excluded due to congenital hearing loss (n = 1) and insufficient data for calculating the platinum dose (n = 24) or for assessing ototoxicity (n = 135). Three hundred and six patients were included in the analysis. Post-chemotherapy ototoxicity was detected in 148 (48%) patients, and clinically-significant ototoxicity was present in 91 (30%). In addition, based on the ASHA criteria, 48% of patients (97/204) with long-term follow-up had further deterioration of their hearing after completion of treatment.

CONCLUSIONS

Ototoxicity following chemotherapy with cisplatin or carboplatin is common and can frequently progress after the completion of treatment. Long-term follow-up is strongly recommended.

Hearing loss in Mexican children treated with cisplatin

OBJECTIVE

Cisplatin is widely used to treat a variety of pediatric solid tumors. One of the most severe and debilitating adverse drug reactions experienced by patients who receive cisplatin therapy is permanent bilateral hearing loss. The aim of this study was to evaluate the incidence and risk factors for cisplatin-induced hearing loss in Mexican pediatric patients.

METHODS

Detailed medical and drug histories, including use of cisplatin as well as other drugs known to cause hearing loss, were collected from patient medical records. Results of audiology tests on pediatric patients with solid tumors were collected at baseline, during treatment and at the end of cisplatin chemotherapy. Hearing loss was classified according to the Common Terminology Criteria for Adverse Events. Bivariate and multivariate analyses were performed using survival curves.

RESULTS

Fifty-nine pediatric patients, median age 11 years (range, 3-17 years) were included in the study. The incidence of cisplatin-induced hearing loss was 56%. Individual risk factors including age (< 5 years), male sex, and concomitant medications were not associated with an increased risk of cisplatin-induced hearing loss. Patients with a diagnosis of osteosarcoma and a cumulative cisplatin dose greater than 400 mg/m(2) were at higher risk of hearing loss compared with all other tumor and cumulative dose combinations (HR = 2.47 [95% CI, 1.043-5.831]).

CONCLUSIONS

Cumulative dose and tumor type are associated with an increased risk of cisplatin-induced hearing loss. Further research is required to characterize fully the interindividual variation in hearing loss in Mexican patients.

Ototoxicity in children with high-risk neuroblastoma: prevalence, risk factors, and concordance of grading scales--a report from the Children's Oncology Group

PURPOSE

Platinum-based therapy is the mainstay for management of high-risk neuroblastoma. Prevalence of platinum-related ototoxicity has ranged from 13% to 95% in previous reports; variability is attributable to small samples and disparate grading scales. There is no consensus regarding optimal ototoxicity grading. Furthermore, prevalence and predictors of hearing loss in a large uniformly treated high-risk neuroblastoma population are unknown. We address these gaps in our study.

PATIENTS AND METHODS

Audiologic testing was completed after administration of cisplatin alone (< 400 mg/m(2); exposure one) or after cisplatin (400 mg/m(2)) plus carboplatin (1,700 mg/m(2); exposure two). Hearing loss was graded using four scales (American Speech-Language-Hearing Association; Brock; Chang; and Common Terminology Criteria for Adverse Events, version 3 [CTCAEv3]).

RESULTS

Of 489 eligible patients, 333 had evaluable audiologic data. Median age at diagnosis was 3.3 years. Prevalence of severe hearing loss differed by scale. For those in the exposure-one group, prevalence ranged from 8% per Brock to 47% per CTCAEv3 (Brock v CTCAEv3 and Chang, P < .01; CTCAEv3 v Chang, P = .16); for those in the exposure-two group, prevalence ranged from 30% per Brock to 71% per CTCAEv3 (all pair-wise comparisons, P < .01). In patients requiring hearing aids, hearing loss was graded as severe in 49% (Brock), 91% (Chang), and 100% (CTCAEv3). Risk factors for severe hearing loss included exposure to cisplatin and carboplatin compared with cisplatin alone and hospitalization for infection.

CONCLUSION

Severe hearing loss is prevalent among children with high-risk neuroblastoma. Exposure to cisplatin combined with myeloablative carboplatin significantly increases risk. The Brock scale underestimates severe hearing loss and should be used with caution in this setting.

Cumulative cisplatin dose is not associated with event-free or overall survival in children with newly diagnosed average-risk medulloblastoma treated with cisplatin based adjuvant chemotherapy: report from the Children's Oncology Group

BACKGROUND

Survival rates for children with medulloblastoma have risen over the past decade, in part due to the addition of cisplatin-containing adjuvant chemotherapy. Total dose of cisplatin required for optimal treatment is unknown. The purpose of this study was to evaluate the survival outcomes based on cumulative cisplatin doses (CCD) in children with newly diagnosed average-risk medulloblastoma.

PROCEDURE

CCD data were reviewed for 363 patients in a prospective study evaluating patients between 3 and 21 years with a newly diagnosed average-risk medulloblastoma and treated with craniospinal radiation and post-radiation cisplatin based adjuvant chemotherapy.

RESULTS

Eight-year event-free survival (EFS) and overall survival (OS) estimates were 78.2 ± 2.6% and 83.9 ± 2.4%, respectively. Only 73 patients received the protocol specified CCD of 600 mg/m(2), primarily due to mandated cisplatin toxicity-related dose reductions. The median CCD given to those without relapse or death on treatment was 487.5 mg/m(2). CCD, as a time-dependent covariate, was not associated with EFS (P = 0.54) or OS (P = 0.11). The 343 patients who completed chemotherapy failure-free were categorized into four groups according to CCD (n = 10; 75-150 mg/m(2)), (n = 26; 151-300 mg/m(2)), (n = 113; 301-450 mg/m(2)), and (n = 194; 451-600 mg/m(2)). There were no statistically significant differences in distributions of EFS (P = 0.53) or OS (P = 0.49) among these four groups.

CONCLUSION

CCD is not associated with EFS or OS suggesting that lower doses of cisplatin may be incorporated into future medulloblastoma trials, thereby limiting its toxicity profile without affecting survival. If ototoxicity is encountered, more stringent cisplatin dose modification/cessation rules seem warranted.

Nanocarriers for delivery of platinum anticancer drugs

Platinum based anticancer drugs have revolutionized cancer chemotherapy, and continue to be in widespread clinical use especially for management of tumors of the ovary, testes, and the head and neck. However, several dose limiting toxicities associated with platinum drug use, partial anti-tumor response in most patients, development of drug resistance, tumor relapse, and many other challenges have severely limited the patient quality of life. These limitations have motivated an extensive research effort towards development of new strategies for improving platinum therapy. Nanocarrier-based delivery of platinum compounds is one such area of intense research effort beginning to provide encouraging preclinical and clinical results and may allow the development of the next generation of platinum chemotherapy. This review highlights current understanding on the pharmacology and limitations of platinum compounds in clinical use, and provides a comprehensive analysis of various platinum-polymer complexes, micelles, dendrimers, liposomes and other nanoparticles currently under investigation for delivery of platinum drugs.

Cisplatin-induced ototoxicity in pediatric solid tumors: the role of glutathione S-transferases and megalin genetic polymorphisms

Cisplatin-induced ototoxicity, an important dose-limiting side effect, has proven high interindividual variability. Glutathione S-transferases (GSTs) are isoenzymes involved in cellular detoxification processes. Megalin has been demonstrated to bind aminoglycosides, known to be similar to cisplatin for their ototoxicity. The GSTs and megalin expression is genetically polymorphic, which might be responsible for the variability in cisplatin-induced ototoxicity. The genotyping of GSTM1, GSTT1 polymorphisms, and 2 nonsynonymous single nucleotide polymorphisms (SNPs) at megalin genes, rs2075252 and rs2228171, were performed in 68 children diagnosed with solid tumors who received cisplatin-based chemotherapy. After the end of treatment, audiometry demonstrated hearing loss in 79.4% of patients according to Brock classification. The cumulative cisplatin dose >400 mg/m is associated with increased risk of cisplatin-induced ototoxicity [odds ratio (OR), 17.5; 95% confidence interval (CI), 3.09-98.62]. GSTT1 wild genotype and C-allele of rs2228171 SNPs of megalin gene occurred with higher frequency in patients with ototoxicity (P=0.023; OR, 10; 95% CI, 1.80-56.00 and P=0.034; OR, 2.67; 95% CI, 1.22-5.82, respectively). In conclusion, our results suggested that GSTT1 wild genotype and C-allele of rs2228171 SNPs might be risk factors for ototoxicity. The cumulative cisplatin dose <400 mg/m should be beneficial in order to ameliorate ototoxicity.

Higher frequency of genetic variants conferring increased risk for ADRs for commonly used drugs treating cancer, AIDS and tuberculosis in persons of African descent

There is established clinical evidence for differences in drug response, cure rates and survival outcomes between different ethnic populations, but the causes are poorly understood. Differences in frequencies of functional genetic variants in key drug response and metabolism genes may significantly influence drug response differences in different populations. To assess this, we genotyped 1330 individuals of African (n=372) and European (n=958) descent for 4535 single-nucleotide polymorphisms in 350 key drug absorption, distribution, metabolism, elimination and toxicity genes. Important and remarkable differences in the distribution of genetic variants were observed between Africans and Europeans and among the African populations. These could translate into significant differences in drug efficacy and safety profiles, and also in the required dose to achieve the desired therapeutic effect in different populations. Our data points to the need for population-specific genetic variation in personalizing medicine and care.

Cancer pharmacogenomics in children: research initiatives and progress to date

Over the last few decades, cure rates for pediatric cancer have increased dramatically, and now over 80 % of children with cancer are cured of their disease. This improvement in cure has come with a significant cost, with many children suffering irreversible, life-threatening, or long-lasting toxicities due to the medications required during their treatment. In the last 2 decades, major technological advances in genomics and the mapping of the human genome have made it possible to identify genetic differences between children in order to investigate differing responses to cancer therapy and to help explain why children treated with the same medications can have different outcomes. The emerging field of pharmacogenomics has had many important findings in pediatric cancer. The focus of this review is drug toxicity in pediatric cancer and the use of pharmacogenomics to reduce these adverse drug reactions, with a specific focus on thiopurines, methotrexate, cisplatin, vincristine and anthracyclines. Future areas of research and the need for international collaboration are discussed.

Ten challenges in the management of neuroblastoma

Neuroblastoma is a complex disease with many contradictions and challenges. It is, by and large, a cancer of babies and preschool children, but it does occur, albeit increasingly rarely, in older children, adolescents and young adults. The prognosis is very variable, with outcome related to age, stage and molecular pathology. Neuroblastoma may behave in an almost benign way, with spontaneous regression in some infants, but the majority of older patients have high-risk disease, which is usually fatal, despite best current treatments. As a rare disease, international collaboration is essential to run clinical trials of adequate statistical power to answer important questions in a reasonable time frame. High-risk disease requires multimodality therapy including chemotherapy, surgery and radiotherapy as well as biological and immunological treatments for optimal outcomes. Innovative treatment approaches, sometimes associated with appreciable toxicity, offer hope for the future but, despite parental wishes, cannot be generally implemented without adequate assessment in clinical trials.

Prospective evaluation of cisplatin- and carboplatin-mediated ototoxicity in paediatric and adult soft tissue and osteosarcoma patients

Platinum-compound chemotherapy is known to have ototoxic side-effects. However, there is a paucity of literature examining hearing function prospectively and longitudinally in cohorts containing paediatric and adult patients treated within the same cisplatin- or carboplatin-containing treatment trial protocols. In Germany, Austria and Switzerland, late effects of treatment for osteosarcoma and soft tissue sarcoma have been prospectively and longitudinally registered by the Late Effects Surveillance System since 1998. The aim of this study was to analyse cisplatin- and carboplatin-induced ototoxity in a group of 129 osteosarcoma and soft tissue sarcoma patients treated within the COSS-96, CWS-96 and CWS-2002P treatment trials. The cohort consisted of 112 children and 17 adults. The median age at diagnosis was 13.56 (IQR, 10.26-16.27) years. Follow-up was 6.97 (IQR, 0.87-15.63) months. Hearing function was examined by audiometry before and after platinum treatment. A total of 108 patients were treated with cisplatin with a median cumulative dose of 360 mg/m(2). Thirteen patients received carboplatin with a median cumulative dose of 1500 mg/m(2) and 8 patients were treated with both platinum compounds (median cisplatin dose, 240 mg/m(2); IQR, 240-360 mg/m(2) and median carboplatin dose: 1200 mg/m(2); IQR, 600-3000 mg/m(2)). Following cessation of therapy, 47.3% of the patients demonstrated a hearing impairment, namely 55 children (49.1%) and 6 adults (42.1%). Out of thirteen children treated with carboplatin with a cumulative dose of 1500 mg/m(2), six revealed a significant hearing impairment. Although ototoxicity caused by platinum compounds is considered irreversible, we identified hearing improvements over time in 11 children (9.8%) and 3 adults (17.6%). None of these patients received irradiation to the head. We conclude that hearing loss is frequent in children treated with protocols containing platinum compounds and recommend prospective testing via audiometry.

Yield of screening for long-term complications using the children's oncology group long-term follow-up guidelines

PURPOSE

The Children's Oncology Group Long-Term Follow-Up (COG-LTFU) Guidelines use consensus-based recommendations for exposure-driven, risk-based screening for early detection of long-term complications in childhood cancer survivors. However, the yield from these recommendations is not known.

METHODS

Survivors underwent COG-LTFU Guideline-directed screening. Yield was classified as negligible/negative (< 1%), intermediate (≥ 1% to < 10%), or high (≥ 10%). For long-term complications with high yield, logistic regression was used to identify subgroups more likely to screen positive.

RESULTS

Over the course of 1,188 clinic visits, 370 childhood cancer survivors (53% male; 47% Hispanic; 69% leukemia/lymphoma survivors; median age at diagnosis, 11.1 years [range, 0.3 to 21.9 years]; time from diagnosis, 10.5 years [range, 5 to 55.8 years]) underwent 4,992 screening tests. High-yield tests included thyroid function (hypothyroidism, 10.1%), audiometry (hearing loss, 22.6%), dual-energy x-ray absorptiometry scans (low bone mineral density [BMD], 23.2%), serum ferritin (iron overload, 24.0%), and pulmonary function testing/chest x-ray (pulmonary dysfunction, 84.1%). Regression analysis failed to identify subgroups more likely to result in high screening yield, with the exception of low BMD (2.5-fold increased risk for males [P = .04]; 3.3-fold increased risk for nonobese survivors [P = .01]). Screening tests with negligible/negative (< 1%) yield included complete blood counts (therapy-related leukemia), dipstick urinalysis for proteinuria and serum blood urea nitrogen/creatinine (glomerular defects), microscopic urinalysis for hematuria (hemorrhagic cystitis, bladder cancer), ECG (anthracycline-related conduction disorder), and hepatitis B and HIV serology.

CONCLUSION

Screening tests with a high yield are appropriate for risk groups targeted for screening by the COG-LTFU Guidelines. Elimination of screening tests with negligible/negative yield should be given consideration.

Risk factors for cisplatin-associated ototoxicity in pediatric oncology patients

BACKGROUND

Cisplatin is an effective chemotherapy agent against several pediatric malignancies. One of its side effects is irreversible sensorineural hearing damage that is highly variable with a reported incidence of 22-70%. The aim of this study was to evaluate the incidence and identify clinical predictors of cisplatin-related ototoxicity.

PROCEDURES

We performed a retrospective chart review of 102 pediatric patients who had completed cisplatin therapy for osteosarcoma, neuroblastoma, hepatoblastoma, or germ cell tumor. Patients were diagnosed at Riley Hospital for Children between January 1995 and June 2008, were less than 18 years old at diagnosis, and had normal hearing prior to therapy. Audiograms were scored using the Brock scale (0-4), a validated grading system for cisplatin-related hearing loss.

RESULTS

Forty-two percent of the patients experienced hearing loss and 28% had moderate to severe ototoxicity (Brock score ≥2). Males were at significantly greater risk for developing hearing loss than were females (P = 0.005, OR 4.812). Age at cancer diagnosis was inversely related to severity of ototoxicity. Patients who suffered Brock grade 3 ototoxicity had a mean age of 4.5 years versus 11.5 years and 7.2 years for grades 1 and 2, respectively (P = 0.02). Cumulative cisplatin dose was also identified as a risk factor for development of ototoxicity (P = 0.03).

CONCLUSIONS

Gender and cumulative dose are important clinical biomarkers of cisplatin ototoxicity. Severity of ototoxicity may be inversely related to age at time of exposure, with very young patients exhibiting higher grades of hearing loss following cisplatin therapy.

Hearing loss among survivors of childhood brain tumors treated with an irradiation-sparing approach

BACKGROUND

Intensive, irradiation-sparing chemotherapy regimens for malignant brain tumors have improved survival and neurocognitive outcomes in very young children. Platinum compounds are pivotal to this approach's success but are associated with hearing loss that markedly reduces quality of life for survivors. The purpose of this study was to determine the prevalence and severity of ototoxicity associated with Head Start and similar irradiation-sparing regimens.

PROCEDURE

A retrospective cohort study was conducted of children treated for malignant brain tumors at Children's Hospital Los Angeles using irradiation-sparing regimens. Patient and treatment characteristics were ascertained. Primary outcomes were post-treatment hearing status, need for hearing aids, and hearing threshold change.

RESULTS

Twenty-nine patients were evaluable. The most common diagnosis was medulloblastoma (n = 14). The median age at diagnosis was 2.0 years (range, 0.2-9.2). Median time from diagnosis to most recent hearing assessment was 1.1 years (mean 2.4; range, 0.2-17.5). Cumulative cisplatin and carboplatin dose was 281 ± 88 mg/m(2) and 1,205 ± 277 mg/m(2) , respectively. All patients had aminoglycoside exposure. Following treatment, 18 patients (62.1%) had abnormal hearing and 11 (37.9%) required hearing aids. At 4,000 Hz, statistically significant hearing loss was documented in the range of 30-40 dB.

CONCLUSIONS

While eliminating cranial irradiation has dramatically improved survival and neurocognitive and neuroendocrine outcomes in this population, clinically significant hearing loss is now the leading late effect due to the necessity of platinum-based chemotherapy. Our results document the need for audiometric monitoring and developing otoprotective strategies in this vulnerable population.

Using germline genomics to individualize pediatric cancer treatments

The amazing successes in cure rates for children with cancer over the last century have come in large part from identifying clinical, genetic, and molecular variables associated with response to therapy in large cooperative clinical trials and stratifying therapies according to the predicted risk of relapse. There is an expanding interest in identifying germline genomic variants, as opposed to genetic variants within the tumor, that are associated with susceptibility to toxicity and for risk of relapse. This review highlights the most important germline pharmacogenetic and pharmacogenomic studies in pediatric oncology. Incorporating germline genomics into risk-adapted therapies will likely lead to safer and more effective treatments for children with cancer.

siRNA-mediated knock-down of NOX3: therapy for hearing loss?

Cisplatin is a widely used chemotherapeutic agent that causes significant hearing loss. Previous studies have shown that cisplatin exposure is associated with increase in reactive oxygen species (ROS) in the cochlea. The inner ear expresses a unique isoform of NADPH oxidase, NOX3. This enzyme may be the primary source of ROS generation in the cochlea. The knockdown of NOX3 by pretreatment with siRNA prevented cisplatin ototoxicity, as demonstrated by preservation of hearing thresholds and inner ear sensory cells. Trans-tympanic NOX3 siRNA reduced the expression of NOX3 and biomarkers of cochlear damage, including transient receptor vanilloid 1 (TRPV1) channel and kidney injury molecule-1 (KIM-1) in cochlear tissues. In addition, siRNA against NOX3 reduced apoptosis as demonstrated by TUNEL staining, and prevented the increased expression of Bax and abrogated the decrease in Bcl2 expression following cisplatin administration. Trans-tympanic administration of siRNA directed against NOX3 may provide a useful method of attenuating cisplatin ototoxicity. In this paper, we review recent publications dealing with the role of NOX3 in ototoxicity and the effects of siRNA against cisplatin-induced hearing loss.

Role of genetic susceptibility in development of treatment-related adverse outcomes in cancer survivors

Clear and unambiguous associations have been established between therapeutic exposures and specific complications. However, considerable interindividual variability is observed in the risk of developing an outcome for a given therapeutic exposure. Genetic predisposition and especially its interaction with therapeutic exposures can potentially exacerbate the toxic effect of treatment on normal tissues and organ systems, and can possibly explain the interindividual variability. This article provides a brief overview of the current knowledge about the role of genomic variation in the development of therapy-related complications. Relatively common outcomes with strong associations with therapeutic exposures, including cardiomyopathy, obesity, osteonecrosis, ototoxicity, and subsequent malignancies are discussed here. To develop a deeper understanding of the molecular underpinnings of therapy-related complications, comprehensive and near-complete collection of clinically annotated samples is critical. Methodologic issues such as study design, definition of the endpoints or phenotypes, identification of appropriate and adequately sized study population together with a reliable plan for collecting and maintaining high-quality DNA, and selection of an appropriate approach or platform for genotyping are also discussed. Understanding the etiopathogenetic pathways that lead to the morbidity is critical to developing targeted prevention and intervention strategies, optimizing risk-based health care of cancer survivors, thus minimizing chronic morbidities and improving quality of life.

Clinically accurate assessment and grading of ototoxicity

OBJECTIVES/HYPOTHESIS

To design a grading scale and audiologic protocols to better reflect clinical impact than the currently widely used classifications.

STUDY DESIGN

Retrospective.

METHODS

Audiologic studies from 130 patients receiving cisplatin chemotherapy were analyzed. Pure-tone audiograms were evaluated using the newly proposed grading criteria, Brock criteria, and Common Terminology Criteria for Adverse Events (CTCAE). The resulting grades were then compared to recommended audiologic interventions. Auditory brainstem response (ABR) data and data on incidences of conductive hearing loss from other multi-institutional studies that the author participated in were compared to data from this cohort.

RESULTS

Although the newly proposed, Brock, and CTCAE ototoxicity grades were significantly related to audiologist recommendations for assistive devices (P < .0001), the newly proposed criteria were more specific and allowed better delineation of different patients into distinct subgroups requiring either FM system (grade 2a) or hearing aid (grade 2b or higher). Multi-institutional data review indicated significant problems with ABR evaluations and separating out conductive hearing losses from ototoxicity.

CONCLUSIONS

The newly proposed grading system needs to be paired with specific recommendations regarding audiologic monitoring protocols as well as active participation by the audiologists implementing the protocol to provide clinically accurate assessment and grading of ototoxicity.

Survival and late effects in children with stage 4 neuroblastoma

BACKGROUND

Treatment of metastatic neuroblastoma (NB) demands aggressive oncological therapy, which may cause long-term sequelae in survivors. The aim of this retrospective single center study is to give an overview of survival in children with stage 4 NB and to describe the spectrum of late effects seen in survivors.

PROCEDURE

Medical records of 31 patients with stage 4 NB treated between 1984 and 2009, who were included in a follow-up programme, were reviewed for information on tumor, treatment and late effects.

RESULTS

Five-year overall survival was 54.3 ± 9% and 5-year event-free survival was 44.9 ± 9%. Patients diagnosed after 1996 had a significantly better survival rate than those diagnosed before (74 ± 11.2% vs. 33.3 ± 12.2%, P = 0.011). In 15 of the 16 survivors (93.8%), numerous late effects were detected. The most common long-term sequelae were renal changes in 10 patients (62.5%) and endocrine disturbances in 9 patients (56.3%), including hypothyroidism with need of substitution in 50%, GH deficiency in 37.5% and hypogonadism in 12.5%. Sensorineural hearing loss occurred in 37.5% of survivors. Further observed late effects were hepatobiliary changes (31.3%), musculoskeletal problems, and pulmonary abnormalities (each 25%), as well as neurologic changes (18.8%), dental defects (12.5%), and unilateral blindness (6.3%). Second neoplasms appeared in 3 patients, 1 of whom died of hepatocellular carcinoma following infection with hepatitis B.

CONCLUSIONS

More than 50% of children with stage 4 NB may survive. The high incidence of severe long-term sequelae underlines the importance of careful follow-up in order to detect and treat late effects early enough.

Cisplatin ototoxicity affecting cochlear implant benefit

OBJECTIVE

Report a case of loss of cochlear implant benefit after cisplatin therapy to treat osteosarcoma. Examine the implications for the loci of cisplatin-associated cochleotoxicity.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Single case study.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Cochlear implant programming levels.

RESULTS

Increase in cochlear implant programming T- and C-levels after cisplatin therapy.

CONCLUSION

Cisplatin therapy likely affects spiral ganglion cells. It seems that auditory cells other than outer hair cells in the organ of Corti are affected by cisplatin because the hearing sensitivity of this patient with nonfunctioning outer hair cells declined after receiving chemotherapy. Implications of these findings are discussed.

Advances in the understanding of constitutional and somatic genomic alterations in neuroblastoma

Advances in the field of genomics have led to multiple recent discoveries in the understanding of genetic predisposition and molecular pathogenesis of the childhood cancer neuroblastoma. Neuroblastoma is the most common extracranial solid tumor of childhood and is responsible for 10% of childhood cancer related mortality. The genetic etiology of rare families with hereditary neuroblastoma is now largely understood, with the majority having activating mutations in the anaplastic lymphoma kinase (ALK) gene. Genome-wide association studies have identified multiple common, low penetrance genetic polymorphisms that are associated with a predisposition to sporadic neuroblastoma, and these associations are disease phenotype specific. While many of the discoveries related to variations in the host genome that predispose to neuroblastoma are recent, there is a long and robust history of investigation of tumor cell genomics, leading to the identification of multiple biomarkers of tumor aggressiveness. Current patient risk stratification algorithms utilize key genomic features for therapy assignment. Microarray-based tumor DNA and RNA profiling techniques and next generation sequencing efforts may further refine these risk groups and identify new tractable therapeutic targets. Moving forward, integrative genomics efforts will be needed to discover how the interaction of germline genetic variations influence oncogenesis in neuroblastoma-both initiation and progression. In this review, we summarize the recent advances in the understanding of germline predisposition and molecular pathogenesis of neuroblastoma.

Auditory complications in childhood cancer survivors: a report from the childhood cancer survivor study

BACKGROUND

Studies have found associations between cancer therapies and auditory complications, but data are limited on long-term outcomes and risks associated with multiple exposures.

PROCEDURE

The Childhood Cancer Survivor Study is a retrospective cohort investigating health outcomes of long-term survivors (5+ years) diagnosed and treated between 1970 and 1986 compared to a randomly selected sibling cohort. Questionnaires were completed by 14,358 survivors of childhood cancer and 4,023 sibling controls. Analysis determined the first occurrence of four auditory conditions in two time periods: diagnosis to 5 years post-diagnosis, and ≥ 5 years post-diagnosis. Multivariable analyses determined the relative risks (RR) and 95% confidence interval (CI) of auditory conditions by treatment exposure.

RESULTS

Five or more years from cancer diagnosis, survivors were at increased risk of problems hearing sounds (RR = 2.3; 95% CI: 1.8-2.8), tinnitus (RR = 1.7; 95% CI: 1.4-2.1), hearing loss requiring an aid (RR = 4.4; 95% CI: 2.8-6.9), and hearing loss in 1 or both ears not corrected by a hearing aid (RR = 5.2; 95% CI: 2.8-9.5), when compared to siblings. Temporal lobe and posterior fossa radiation was associated with these outcomes in a dose-dependent fashion. Exposure to platinum compounds was associated with an increased risk of problems hearing sounds (RR = 2.1; 95% CI: 1.3-3.2), tinnitus (RR = 2.8; 95% CI: 1.9-4.2), and hearing loss requiring an aid (RR = 4.1; 95% CI: 2.5-6.7).

CONCLUSIONS

Childhood cancer survivors are at risk of developing auditory complications. Radiation and platinum compounds are determinants of this risk. Follow-up is needed to evaluate the impact of auditory conditions on quality of life.

Pharmacogenomics of cisplatin-induced ototoxicity

Cisplatin ototoxicity affects different individuals in a widely variable manner. These variations are likely to be explained by genetic differences among those affected. It would be highly advantageous to identify genetic variants that predispose to cisplatin ototoxicity in order to minimize the risk to susceptible subgroups. Although this area of research is very important, only a few studies have rigorously examined the genetic basis for cisplatin-induced susceptibility to hearing loss. This article addresses recent progress in clarifying the incidence of cisplatin ototoxicity and the risk factors and controversies regarding the identification of genetic variants associated with cisplatin-induced hearing loss.

N-acetylcysteine and N-nitroarginine methyl ester attenuate Carboplatin-induced ototoxicity in dissociated spiral ganglion neuron cultures

Objectives

Carboplatin, a platinum-containing anti-cancer drug used to treat a variety of cancers, induces ototoxicity. Since, reactive oxygen species (ROS) and nitric oxide (NO) seem to be responsible for this toxicity, the antioxidant, N-acetyl-L-cysteine (L-NAC), and NO synthetase inhibitor, N-nitro-L-arginine methyl ester (L-NAME) were predicted to have protective effects against carboplatin ototoxicity. The aim of this study was to test for the protective effects of L-NAC and L-NAME on cochlear hair cells and spiral ganglion neurons (SGNs).

Methods

Cochlear organotypic cultures and dissociated spiral ganglion neuron cultures, from mice postnatal day 5 cultures were used in this study. The cultures were treated with carboplatin alone or in combination with L-NAC or L-NAME, and carboplatin-induced damage was monitored.

Results

Treatment with carboplatin induced a significant loss of outer hair cells, while inner hair cells were preserved in the cochlear organotypic cultures. Addition of L-NAC or L-NAME reduced the amount of carboplatin-induced hair cell damage; the differences did not reach statistical significance. However, carboplatin significantly decreased the number of surviving SGNs in dissociated cultures. The toxic effects were significantly reduced by addition of L-NAC or L-NAME. In addition, carboplatin induced the loss of neurites from the SGN somata, and this was not blocked with L-NAC or L-NAME.

Conclusion

The results of this study suggest that ROS and NO are involved in carboplatin-induced damage to hair cells and SGNs, and administration of L-NAC/L-NAME can be used to attenuate the toxicity.

Do pharmacokinetic polymorphisms explain treatment failure in high-risk patients with neuroblastoma?

PURPOSE

Neuroblastoma is the most common extracranial solid tumour in childhood. It accounts for 15% of all paediatric oncology deaths. In the last few decades, improvement in treatment outcome for high-risk patients has not occurred, with an overall survival rate <30-40%. Many reasons may account for such a low survival rate. The aim of this review is to evaluate whether pharmacogenetic factors can explain treatment failure in neuroblastoma.

METHODS

A literature search based on PubMed's database Medical Subject Headings (MeSH) was performed to retrieve all pertinent publications on current treatment options and new classes of drugs under investigation. One hundred and fifty-eight articles wer reviewed, and relevant data were extracted and summarised.

RESULTS AND CONCLUSIONS

Few of the large number of polymorphisms identified thus far showed an effect on pharmacokinetics that could be considered clinically relevant. Despite their clinical relevance, none of the single nucleotide polymorphisms (SNPs) investigated can explain treatment failure. These findings seem to reflect the clinical context in which anti-tumour drugs are used, i.e. in combination with multimodal therapy. In addition, many pharmacogenetic studies did not assess (differences in) drug exposure, which could contribute to explaining pharmacogenetic associations. Furthermore, it remains unclear whether the significant activity of new drugs on different neuroblastoma cell lines translates into clinical efficacy, irrespective of resistance or myelocytomatosis viral related oncogene, neuroblastoma derived (MYCN) amplification. Elucidation of the clinical role of pharmacogenetic factors in the treatment of neuroblastoma demands an integrated pharmacokinetic-pharmacodynamic approach to the analysis of treatment response data.

Pharmacogenomics and active surveillance for serious adverse drug reactions in children

Juxtaposing clinical pharmacology with human genetics, pharmacogenomics utilizes a patient’s genetic information to identify genetic variants that have the potential to provide clinically relevant predictions of toxicity and efficacy. The goal is to develop personalized and genetic-based predictions of an individual’s drug response and likelihood of experiencing an adverse drug reaction. The Canadian Pharmacogenomics Network for Drug Safety (CPNDS) has implemented active adverse drug reaction surveillance to monitor and discover genetic markers related to serious adverse drug reactions in the pediatric population. Evidence-based pharmacogenomics research will inform public policy and influence drug benefit–risk decision-making. Regulatory processes and future challenges in pharmacogenomics research will be discussed.

The Canadian Pharmacogenomics Network for Drug Safety: a model for safety pharmacology

BACKGROUND

Adverse drug reactions (ADRs) rank as one of the top 10 leading causes of death in the developed world, and the direct medical costs of ADRs exceed $100 billion annually in the United States alone. Pharmacogenomics research seeks to identify genetic factors that are responsible for individual differences in drug efficacy and susceptibility to ADRs. This has led to several genetic tests that are currently being used to provide clinical recommendations. The Canadian Pharmacogenomics Network for Drug Safety is a nation-wide effort established in Canada to identify novel predictive genomic markers of severe ADRs in children and adults. A surveillance network has been established in 17 of Canada's major hospitals to identify patients experiencing specific ADRs and to collect biological samples and relevant clinical history for genetic association studies. To identify ADR-associated genetic markers that could be incorporated into predictive tests that will reduce the occurrence of serious ADRs, high-throughput genomic analyses are conducted with samples from patients that have suffered serious ADRs and matched control patients.

SUMMARY

ADRs represent a significant unmet medical problem with significant morbidity and mortality, and Canadian Pharmacogenomics Network for Drug Safety is a nation-wide network in Canada that seeks to identify genetic factors responsible for interindividual differences in susceptibility to serious ADRs.

CONCLUSIONS

Active ADR surveillance is necessary to identify and recruit patients who suffer from serious ADRs. National and international collaborations are required to recruit sufficient patients for these studies. Several pharmacogenomics tests are currently in clinical use to provide dosing recommendations, and the number of pharmacogenomics tests is expected to significantly increase in the future.

Report on hearing loss in oncology

Cisplatin is used frequently as an antineoplastic drug in the treatment of many different cancers. However, when used in doses over 360mg/m², ototoxicity may ensue, resulting in loss of hearing. Criteria for identifying and quantifying hearing loss have been devised.

Aim

To describe the features of different hearing loss classification systems and to identify their implications and use in oncologic patients.

Method

Hearing loss was classified in 31 patients before and after chemotherapy, according to different criteria, assessing the sensitivity and specificity of each classification system.

Results

Hearing loss results were highly variable (ranging from 29% to 61%). Only 4 of 31 subjects with post-therapy hearing loss were identified by all the methods. A few subjects with hearing loss were classified as normal hearing in some of the criteria. A normal PTA was found in 18 of 31 subjects in the post-treatment evaluation.

Conclusion

None of the criteria assesses the complaints of patients. The criteria described in this study were inadequate to identify hearing loss following chemotherapy, requiring additional information for physicians to better understand the hearing losses and their implications for the quality of life of patients.

Mortality and morbidity of patients with neuroblastoma who survived for more than 10 years after treatment--Niigata Tumor Board Study

PURPOSE

To evaluate the utility of treatment strategies in neuroblastoma (NB), the survival of the NB patients was retrospectively examined.

METHODS

During the past 40 years from 1967 to 2006, 103 NB patients not detected by the mass screening program were treated. The patients were divided into 3 groups; the period of aggressive surgery (AS group: 43 patients) from 1967 to 1984, the period of aggressive chemotherapy (AC group: 40 patients), from 1985 to 1996, and the period of mega-chemotherapy with stem cell transplantation since 1997. The patients treated in the AC and the AS groups were examined.

RESULTS

The survival curve reached a nadir within 3 years in the AS group, whereas the second major drop of the survival curve was found in the AC group, which was owing to late mortality of 7 patients more than 10 years after the initiation of treatment. As a result, the overall survival in the AS and the AC groups were approximately 30.2% and 30.0% at 20 years after treatment, respectively. A different kind of strategy-related morbidity was found in 46% of EFS in both the AS and the AC groups.

CONCLUSIONS

The effectiveness of a treatment strategy should therefore be assessed after several decades.

Peripheral blood stem cell support for multiple cycles of dose intensive induction therapy is feasible with little risk of tumor contamination in advanced stage neuroblastoma: a report from the Childrens Oncology Group

BACKGROUND

Poor outcome in Stage 4 neuroblastoma may be improved with increased dose intensity of therapy. We investigated the feasibility of sequential collection and infusion of peripheral blood stem cells (PBSCs) as hematopoietic support for non-myeloablative dose intensive induction chemotherapy given every 21-28 days.

METHODS

Twenty-two children with Stage 4 neuroblastoma (>or=1 year of age) received two cycles of high-dose cyclophosphamide (4 g/m(2)), doxorubicin (75 mg/m(2)), and vincristine (2 mg/m(2)) followed by three cycles of interpatient dose escalating carboplatin (Dose Level 0 = 800 mg/m(2); Dose Level 1 = 1,000 mg/m(2)), high-dose cyclophosphamide (4 g/m(2)), and etoposide (600 mg/m(2)). PBSC were harvested following cycle 2, 3, and 4 in Cohort 1 and infused after each subsequent cycle. In Cohort 2, PBSC were harvested after cycle 2 and split into three aliquots for infusion. Dose limiting toxicity (DLT) and ability to administer cycles within 28 days was assessed.

RESULTS

Sufficient PBSC (>or=2 x 10(6) CD34 cells/kg per infusion) were collected from 17/21 eligible patients with minimal toxicity and no detectable neuroblastoma cells by immunocytology. Carboplatin at 1000 mg/m(2) resulted in DLT of delayed platelet recovery >28 days in 4/8 patients. Despite de-escalation to 800 mg/m(2), platelet DLT occurred in 4/7 Cohort 1 and 3/7 Cohort 2 patients.

CONCLUSION

As defined in this protocol, doses of carboplatin were not tolerable with the PBSC dose administered. However, it was feasible to collect sufficient PBSC from small neuroblastoma patients to use as hematopoietic support with minimal risk of tumor contamination and toxicity.

Auditory late effects of childhood cancer therapy: a report from the Children's Oncology Group

Children treated for malignancies may be at risk for early- or delayed-onset hearing loss that can affect learning, communication, school performance, social interaction, and overall quality of life. Survivors at particular risk include those treated with platinum compounds (cisplatin and/or carboplatin) for neuroblastoma, hepatoblastoma, osteosarcoma, or germ-cell tumors and/or those treated with radiation that affects the ear at doses of >30 Gy for pediatric head and neck tumors. The aims of the Auditory/Hearing Late Effects Task Force of the Children's Oncology Group in this report were to (1) review ototoxicity resulting from childhood cancer therapy including platinum compounds (cisplatin and carboplatin) and radiation, (2) describe briefly cochlear pathophysiology and genetics of cisplatin-related hearing loss, (3) explain the impact of hearing loss resulting from chemotherapy and radiation, and (4) offer recommendations regarding evaluation and management of pediatric patients who are at risk for treatment-related hearing loss. A questionnaire is included as a tool to assist pediatricians in assessment.

Practical grading system for evaluating cisplatin ototoxicity in children

PURPOSE

We present a new ototoxicity grading system that has clearly defined and frequency-specific audiometric criteria. The purpose of this study was to validate this grading system by assessing its correspondence to audiology treatment recommendations and comparing it with the currently utilized Common Terminology Criteria for Adverse Events (CTCAE).

PATIENTS AND METHODS

A retrospective chart review was conducted using audiologic, demographic, and clinical data from 134 children receiving 149 courses of chemotherapy consisting of cisplatin and/or carboplatin. Pure-tone audiograms were evaluated using both our proposed grading criteria and the CTCAE criteria. The resulting grades were then compared with charted audiologic interventions and a number of clinical parameters to assess the clinical validity of the grading scale.

RESULTS

Chang grade 2a or higher predicted audiologic intervention. Although both the Chang and CTCAE ototoxicity grades were significantly related to audiologist recommendations for assistive devices such as hearing aids and/or frequency modulated systems (P < .0001), the Chang scale was more specific, with the CTCAE scale diverging from clinical recommendation at higher grades. As expected, patients receiving cisplatin had more severe hearing loss with concurrent carboplatin administration, radiation therapy exposure, younger age, smaller body-surface area, longer treatment exposure, and more severe disease.

CONCLUSION

This grading system provides robust and clinically useful criteria to represent clinical hearing loss induced by ototoxicity with regard to the impact on speech and language and the need for assistive hearing devices. It is both more specific and more sensitive than the traditional CTCAE criteria for identifying clinically significant ototoxicity.

Genetic variants in TPMT and COMT are associated with hearing loss in children receiving cisplatin chemotherapy

Cisplatin is a widely used and effective chemotherapeutic agent, although its use is restricted by the high incidence of irreversible ototoxicity associated with it. In children, cisplatin ototoxicity is a serious and pervasive problem, affecting more than 60% of those receiving cisplatin and compromising language and cognitive development. Candidate gene studies have previously reported associations of cisplatin ototoxicity with genetic variants in the genes encoding glutathione S-transferases and megalin. We report association analyses for 220 drug-metabolism genes in genetic susceptibility to cisplatin-induced hearing loss in children. We genotyped 1,949 SNPs in these candidate genes in an initial cohort of 54 children treated in pediatric oncology units, with replication in a second cohort of 112 children recruited through a national surveillance network for adverse drug reactions in Canada. We identified genetic variants in TPMT (rs12201199, P value = 0.00022, OR = 17.0, 95% CI 2.3-125.9) and COMT (rs9332377, P value = 0.00018, OR = 5.5, 95% CI 1.9-15.9) associated with cisplatin-induced hearing loss in children.

Long-term outcomes in survivors of neuroblastoma: a report from the Childhood Cancer Survivor Study

BACKGROUND

The 5-year survival rate for individuals with neuroblastoma is approaching 70%. Few data exist, however, on the long-term outcomes of these patients, who are often treated at a very young age.

METHODS

Outcome data were obtained for 954 5-year neuroblastoma survivors who were diagnosed in 1970-1986 and enrolled in the Childhood Cancer Survivor Study (CCSS). Late mortality, second malignant neoplasms, and chronic health conditions were analyzed in relation to treatment factors using Poisson regression models and their modification with generalized estimating equations. Neuroblastoma survivors were compared with a cohort of 3899 siblings of CCSS participants for risk of chronic health conditions and selected sociodemographic outcomes. All statistical tests were two-sided.

RESULTS

Six percent of patients died more than 5 years after their diagnosis (standardized mortality ratio = 5.6; 95% confidence interval [CI] = 4.4 to 6.9). The most common causes of death were disease recurrence (n = 43) and second malignant neoplasms (n = 13). The cumulative incidence of second malignant neoplasms was 3.5% at 25 years and 7.0% at 30 years after diagnosis. Compared with the sibling cohort, survivors had an increased risk of selected chronic health conditions (risk ratio [RR] = 8.3; 95% CI = 7.1 to 9.7) with a 20-year cumulative incidence of 41.1%. The most prevalent outcomes involved the neurological, sensory, endocrine, and musculoskeletal systems, with 20-year cumulative incidences of 29.8%, 8.6%, 8.3%, and 7.8%, respectively. Neuroblastoma survivors who were treated with multimodality therapy were more likely to develop a chronic health condition than survivors treated with surgery alone (RR = 2.2; 95% CI = 1.6 to 3.0). Neuroblastoma survivors were less likely than siblings to have ever been employed (P = .04) or to be married (P < .001) and had a lower personal income (P = .009).

CONCLUSIONS

Neuroblastoma survivors have an increased rate of mortality and second malignant neoplasms, relative to the age- and sex-comparable US population, and of chronic health conditions, relative to their siblings, which underscores the need for long-term medical surveillance.

Hyperfractionated low-dose (21 Gy) radiotherapy for cranial skeletal metastases in patients with high-risk neuroblastoma

PURPOSE

To present a large experience (73 patients) using a standard radiotherapy (RT) protocol to prevent relapse in cranial sites where measurable metastatic neuroblastoma (NB), an adverse prognostic marker, is common.

METHODS AND MATERIALS

High-risk NB patients with measurable cranial disease at diagnosis or residual cranial disease after induction therapy had those sites irradiated with hyperfractionated 21 Gy; a brain-sparing technique was used for an extensive field. The patients were grouped according to the response to systemic therapy. Thus, when irradiated, Group 1 patients were in complete remission and Group 2 patients had primary refractory disease. Follow-up was from the start of cranial RT.

RESULTS

At 3 years, the 39 Group 1 patients had a progression-free survival rate of 51%; control of cranial disease was 79%. Two relapses involved irradiated cranial sites. Two other patients relapsed in the irradiated cranial sites 6 and 12 months after a systemic relapse. At 3 years, the 34 Group 2 patients had a progression-free survival rate of 33%; control of cranial disease was 52%. Group 2 included 19 patients who had residual cranial (with or without extracranial) disease. The cranial sites showed major (n = 13), minor (n = 2), or no response (n = 4) to RT. Five patients had progression in the cranial RT field at 10-27 months. Group 2 also included 15 patients who had persistent NB in extracranial, but not cranial, sites. Of these 15 patients, 2 relapsed in the irradiated cranial sites and elsewhere at 8 and 14 months. Cranial RT was well tolerated, with no Grade 2 or greater toxicity.

CONCLUSION

Hyperfractionated 21-Gy cranial RT might help control NB and is feasible without significant toxicity in children.

Genetic variants associated with cisplatin-induced ototoxicity

Cisplatin induces ototoxicity with a huge interindividual variation, which is at least partly based on genetic differences between the affected individuals. Identification of genetic variants that could predict the severity of ototoxicity is an important step towards a more individualized cisplatin treatment. Nevertheless, so far, only a few studies have assessed this issue. This review will address the prevalence of cisplatin-induced ototoxicity, its pathophysiology, quantification and associations with genetic variants. The recent progress in both phenotyping and genotyping is discussed.

Late effects in survivors of tandem peripheral blood stem cell transplant for high-risk neuroblastoma

BACKGROUND

Increasing numbers of children with advanced neuroblastoma are achieving cure. We describe the clinical late effects specific to survivors of stage IV neuroblastoma all similarly treated using tandem autologous peripheral blood stem cell rescue with TBI.

METHOD

The medical records of 35 neuroblastoma patients treated at CHOP between 1997 and 2001 were examined. Eighteen of the 35 patients died of progressive disease, and 4 were lost to follow-up. Thirteen patients continue to follow-up in our Multidisciplinary Cancer Survivorship Clinic where they are evaluated and monitored by a consistent group of subspecialists that evaluate long-term sequelae. Data on treatment exposures including TBI and treatment related sequelae identified by clinician assessment and/or diagnostic testing were collected.

RESULTS

Results indicate late effects were present in all 13 subjects, 12 of whom suffered from multiple negative sequelae, including issues with growth hormone deficiency, dental problems, osteochondromas and hearing deficiencies, among others, most at higher rates than reported previously.

CONCLUSIONS

The findings in this small cohort indicate the need for future prospective studies of this intensive pediatric cancer treatment, and underscore the importance of medical intervention and long-term monitoring of these at-risk subjects to increase overall quality-of-life.