Long-term effect of chemotherapy-intensity-modulated radiation therapy (chemo-IMRT) on dentofacial development in head and neck rhabdomyosarcoma patients

Bone age and dental late effects in childhood cancer survivors: Radiographic findings in a Brazilian sample

BACKGROUND

Changes in bone age and tooth development are late side effects of cancer therapy and can be identified by imaging examination.

AIM

To evaluate the late effects of antineoplastic treatment on bone age and dental development in childhood cancer survivors.

DESIGN

This is a retrospective case-control study on paediatric cancer survivors of both sexes who underwent antineoplastic treatment with 5-15 years of survival. Carpal radiographs were assessed for bone age and growth curve, and panoramic radiographs were used to evaluate dental development and alterations. Carpal radiographs were analyzed using the Greulich and Pyle inspection method, and the Martins and Sakima method was used to analyze the growth curve. All tests were applied with a confidence level of 95%.

RESULTS

The study and control groups comprised 28 and 56 patients, respectively. There was no significant difference in bone age and growth curve between the study and control groups. Nonetheless, when sex was compared to chronological and bone ages, there was a significant difference in bone age (p = 0.019) and an underestimation in both groups and sexes in the Greulich and Pyle method. As to late dental effects, dental agenesia, microdontia, gyroversion, and unerupted teeth were found. Dental shape alterations mainly involve the root region.

CONCLUSION

Close multidisciplinary collaboration is necessary during the follow-up period of young patients who have survived cancer.

NF1-Driven Rhabdomyosarcoma Phenotypes: A Comparative Clinical and Molecular Study of NF1-Mutant Rhabdomyosarcoma and NF1-Associated Malignant Triton Tumor

PURPOSE

Alterations of the NF1 tumor suppressor gene is the second most frequent genetic event in embryonal rhabdomyosarcoma (ERMS), but its associations with clinicopathologic features, outcome, or coexisting molecular events are not well defined. Additionally, NF1 alterations, mostly in the setting of neurofibromatosis type I (NF1), drive the pathogenesis of most malignant peripheral nerve sheath tumor with divergent RMS differentiation (also known as malignant triton tumor [MTT]). Distinguishing between these entities can be challenging because of their pathologic overlap. This study aims to comprehensively analyze the clinicopathologic and molecular spectrum of NF1-mutant RMS compared with NF1-associated MTT for a better understanding of their pathogenesis.

METHODS

We investigated the clinicopathologic and molecular landscape of a cohort of 22 NF1-mutant RMS and a control group of 13 NF1-associated MTT. Cases were tested on a matched tumor-normal hybridization capture-based targeted DNA next-generation sequencing.

RESULTS

Among the RMS group, all except one were ERMS, with a median age of 17 years while for MTT the mean age was 39 years. Three MTTs were misdiagnosed as ERMS, having clinical impact in one. The most frequent coexisting alteration in ERMS was TP53 abnormality (36%), being mutually exclusive from NRAS mutations (14%). MTT showed coexisting CDKN2A/B and PRC2 complex alterations in 38% cases and loss of H3K27me3 expression. Patients with NF1-mutant RMS exhibited a 70% 5-year survival rate, in contrast to MTT with a 33% 5-year survival. All metastatic NF1-mutant ERMS were associated with TP53 alterations.

CONCLUSION

Patients with NF1-mutant ERMS lacking TP53 alterations may benefit from dose-reduction chemotherapy. On the basis of the diagnostic challenges and significant treatment and prognostic differences, molecular profiling of challenging tumors with rhabdomyoblastic differentiation is recommended.

An analysis of muscle growth after proton beam therapy for pediatric cancer

Retardation of growth and development is a well-known late effect after radiotherapy for pediatric patients. The goal of the study was to examine the effect of proton beam therapy (PBT) on the growth of muscles included in the irradiated area. The subjects were 17 pediatric patients (age ≤ 5 years) who received PBT with a treatment field including a muscle on only one side out of a pair of symmetrical bilateral muscles and had imaging evaluations for at least 1 year after PBT. The thicknesses of the irradiated and non-irradiated (contralateral) muscles were measured retrospectively on CT or MRI axial images collected before and after PBT. The change of thickness divided by the period (years) for each muscle was compared between the irradiated and contralateral sides. Correlations of muscle growth with irradiation dose and age at the start of treatment were also evaluated. The median observation period was 39.2 months. The measurement sites included the erector spinae (n = 9), gluteus maximus (n = 5) and rhomboids + trapezius (n = 3) muscles. The average changes in muscle thickness were 0.24 mm/year on the irradiated side and 1.19 mm/year on the contralateral side, showing significantly reduced growth on the irradiated side (P = 0.001). Younger patients had greater muscle growth. Irradiation dose was not significant, but muscle growth tended to decrease as the dose increased, and muscles irradiated at >50 Gy (RBE) showed little growth. These results show that muscle growth is affected by PBT and that long-term follow-up is needed to evaluate muscle growth retardation.

Prevalence of, and risk factors for, dental sequelae in adolescents who underwent cancer therapy during childhood

INTRODUCTION

The increase in survival rates in children treated for cancer has been accompanied by a rise in sequelae in permanent teeth. The aim of the study was to correlate the type of cancer therapy administered to patients during early childhood and the dental sequelae recorded in survivors.

MATERIAL AND METHODS

Single-center retrospective cohort study carried out at the Children's University Hospital of Sant Joan de Déu in Barcelona, Spain. Hundred and nine patients who had received cancer treatment during early childhood were randomly examined and grouped according to diagnosis and cancer therapy received. The type of therapy was correlated with the number and severity of dental lesions that patients presented in adolescence.

RESULTS

Dental sequelae of some kind were present in 85.3% of patients. Microdontia was the most prevalent (52.3%). Treatment with alkylating agents had a relative risk of presenting moderate lesions of 3.36 (1.18-9.60), and one of 2.29 (1.07-4.91) of presenting severe lesions. Topoisomerase inhibitors and cytotoxic antibiotics presented relative risks of 1.6 (1.07-2.38) and 2.08 (1.02-4.26) of root alterations and agenesis, respectively.

CONCLUSIONS

Treatment with alkylating agents together with cytotoxic antibiotics and topoisomerase inhibitors was associated with a higher relative risk of microdontia, agenesis, and root shortening.

Chemotherapy and Radiotherapy Long-Term Adverse Effects on Oral Health of Childhood Cancer Survivors: A Systematic Review and Meta-Analysis

The survival rate for pediatric cancer has increased over the past few decades, short- and long-term complications have been detected and studied, and oral complications have emerged as an important topic of research. Here, we aimed to highlight the importance of oral manifestations that may only become apparent years or even decades after cancer treatment. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. We searched articles using PubMed via the MEDLINE, Web of Science, and LILACS databases until October 2023. Overall, 35 observational studies were included, and the results estimated a pooled prevalence of the following dental anomalies: discoloration, 53%; crown-root malformations and agenesis, 36%; enamel hypoplasia, 32%; root development alterations, 29%; unerupted teeth, 24%; microdontia, 16%; hypodontia, 13%; and macrodontia, 7%. Most childhood cancer survivors have at least one dental sequela. Childhood cancer survivors presented a higher risk of having dental alterations than control counterparts. Additional analyses reveal possible sex-based differences that should be explored in future studies. These results collectively highlight the importance of oral healthcare and the prevention of disease in childhood cancer survivors.

Extremity Rhabdomyosarcoma-An Integrated Clinicopathologic and Genomic Study to Improve Risk Stratification

PURPOSE

Extremity rhabdomyosarcoma (RMS) is associated with a very poor outcome compared with other sites, mainly because of its high incidence of alveolar histology and regional lymph node involvement. To better define prognostic markers in this clinical subset, we investigated our experience of 61 patients with extremity RMS treated at our tertiary cancer center for the past 2 decades.

PATIENTS AND METHODS

The patients had a median age of 8 years at diagnosis, equal gender distribution, and two-thirds occurred in the lower extremity. Most (85%) patients had FOXO1 fusion-positive alveolar RMS (ARMS), with 70% having a PAX3::FOXO1 transcript. Remaining were seven patients with fusion-negative embryonal RMS (ERMS) and two with MYOD1-mutant spindle cell/sclerosing RMS (SRMS). In 40% of the patients, material was available for DNA-based targeted sequencing using MSK-IMPACT cancer gene panel.

RESULTS

One-third of patients presented with localized disease at diagnosis while the remaining had regional nodal (18%) or distant metastases (51%). Metastatic disease, high-risk group, and age 10 years or older significantly affected the overall survival (OS; hazard ratio [HR], 2.68 [P = .004], 2.78 [P = .010] and 2.26 [P = .034], respectively). Although the presence of metastatic disease had a dismal impact on 5-year EFS and OS (19% and 29%, respectively), nodal involvement had a comparatively lower impact on 5-year EFS and 5-year OS (43% and 66%, respectively). PAX3::FOXO1 ARMS had worse prognosis and afflicted older children compared with PAX7::FOXO1 (HR = 3.45, P = .016). The most common events in the ARMS group included MED12 alterations, CDK4 amplifications, and CDKN2A deletions (8%-17%). The latter two abnormalities were mutually exclusive, enriched for acral and high-risk lesions, and correlated with poor outcome on OS (P = .02).

CONCLUSION

Our data provide rationale for considering the integration of molecular abnormalities to refine risk stratification in extremity RMS.

The Role of Dental Practitioners in the Management of Oncology Patients: The Head and Neck Radiation Oncology Patient and the Medical Oncology Patient

This narrative review addresses the role of a dentist in the management of oncology patients, highlighting the oral complications that arise in head and neck radiation oncology patients and medical oncology patients. The prevention and management of these complications are discussed.

Surfaceome Profiling of Cell Lines and Patient-Derived Xenografts Confirm FGFR4, NCAM1, CD276, and Highlight AGRL2, JAM3, and L1CAM as Surface Targets for Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. The prognosis for patients with high-grade and metastatic disease is still very poor, and survivors are burdened with long-lasting side effects. Therefore, more effective and less toxic therapies are needed. Surface proteins are ideal targets for antibody-based therapies, like bispecific antibodies, antibody-drug conjugates, or chimeric antigen receptor (CAR) T-cells. Specific surface targets for RMS are scarce. Here, we performed a surfaceome profiling based on differential centrifugation enrichment of surface/membrane proteins and detection by LC-MS on six fusion-positive (FP) RMS cell lines, five fusion-negative (FN) RMS cell lines, and three RMS patient-derived xenografts (PDXs). A total of 699 proteins were detected in the three RMS groups. Ranking based on expression levels and comparison to expression in normal MRC-5 fibroblasts and myoblasts, followed by statistical analysis, highlighted known RMS targets such as FGFR4, NCAM1, and CD276/B7-H3, and revealed AGRL2, JAM3, MEGF10, GPC4, CADM2, as potential targets for immunotherapies of RMS. L1CAM expression was investigated in RMS tissues, and strong L1CAM expression was observed in more than 80% of alveolar RMS tumors, making it a practicable target for antibody-based therapies of alveolar RMS.

Long-term effects of chemotherapy and radiation received during early childhood on the developing dentition of pediatric cancer patients

INTRODUCTION

The short-term effects of chemotherapy and irradiation are well documented; however, there is paucity regarding their long-term effects, especially in children and adolescents.

CASE DESCRIPTION

This paper discusses the long-term effects of chemotherapy and/or radiation received by the patients during their early childhood on the developing dentition. It comprises the compilation of 11 cases with alteration in the dental development screened from 138 cases of the childhood cancer patients who received the chemotherapy and/or radiation as a part of anticancer therapy.

RESULTS AND CONCLUSION

The findings revealed that the age of initiation of anticancer therapy along with the synergistic effect of chemo-irradiation, and the dose of radiation used were the principal determinants for the dental abnormalities. The root-related abnormalities were found to be varied and more common as compared to the missing teeth and defects related to the tooth crown.

Quantum Dot-Based Screening Identifies F3 Peptide and Reveals Cell Surface Nucleolin as a Therapeutic Target for Rhabdomyosarcoma

Active drug delivery by tumor-targeting peptides is a promising approach to improve existing therapies for rhabdomyosarcoma (RMS), by increasing the therapeutic effect and decreasing the systemic toxicity, e.g., by drug-loaded peptide-targeted nanoparticles. Here, we tested 20 different tumor-targeting peptides for their ability to bind to two RMS cell lines, Rh30 and RD, using quantum dots Streptavidin and biotin-peptides conjugates as a model for nanoparticles. Four peptides revealed a very strong binding to RMS cells: NCAM-1-targeting NTP peptide, nucleolin-targeting F3 peptide, and two Furin-targeting peptides, TmR and shTmR. F3 peptide showed the strongest binding to all RMS cell lines tested, low binding to normal control myoblasts and fibroblasts, and efficient internalization into RMS cells demonstrated by the cytoplasmic delivery of the Saporin toxin. The expression of the nucleophosphoprotein nucleolin, the target of F3, on the surface of RMS cell lines was validated by competition with the natural ligand lactoferrin, by colocalization with the nucleolin-binding aptamer AS1411, and by the marked sensitivity of RMS cell lines to the growth inhibitory nucleolin-binding N6L pseudopeptide. Taken together, our results indicate that nucleolin-targeting by F3 peptide represents a potential therapeutic approach for RMS.

TAI CHI IMPACTS ON NEUROMUSCULAR FUNCTIONS IN THE LOWER LIMBS OF THE ELDERLY

ABSTRACT Introduction: Exercise can retard the effects of aging and improve the physical function of the elderly. Tai Chi is a widespread exercise practice among the elderly in China. Although studies show the positive effects of Tai Chi practice, there is no consensus about compared studies. Objective: Evaluate the impact of regular Tai Chi exercise on neuromuscular stability in the lower limbs of elderly people, comparing the results of practitioners between sedentary and walking elderly groups. Methods: Twenty-two Tai Chi practitioners were selected, with a mean age of 59.3±3.5 years and a mean practice time of 18.4±13.2 years. This experiment mainly tests the balance ability compared to individuals practicing walking and other sedentary individuals. Results: The muscle strength of the knee flexors and extensors in the Tai Chi group was significantly greater than in the sedentary group (p=0.001 to 0.00160°/sec; P=0.002 to 60°/sec extensors; p=0.002 to 120°/sec; 120°/sec flexors, p=0.003). Similarly, there was a significant difference in muscle strength between the Tai Chi group and the walking group (the P values of the flexors and extensors at both speeds were less than 0.001). Conclusion: Tai Chi, as a regular exercise, can increase muscle strength of the general knee flexors and extensors and improve the neuromuscular stability of lower limbs in the elderly. Evidence Level II; Therapeutic Studies - Investigating the result.

Long-Term Effect of Anticancer Therapy on Dentition in Childhood Cancer Survivors: An Observational, Cross-Sectional Study

OBJECTIVES

To evaluate the presence of developmental dental anomalies, like microdontia, hypodontia, abnormally shaped teeth (AST), and developmental defects of enamel (DDE) in childhood cancer survivors and compare it with the healthy controls.

METHODS

This cross-sectional analytical study was conducted in 2 groups: childhood cancer survivors (CCS) group including children (> 12 y, m/f) who had undergone anticancer therapy (ACT) before 8 y of age and healthy control group (> 12 y, m/f) without any systemic disease. Pearson chi-square test was used to analyze the difference between the CCS group and the control group for microdontia, hypodontia, AST, DDE and for intragroup analysis in CCS group. Odds ratio was also calculated.

RESULTS

A total of 120 and 121 children were included in CCS and control group, respectively. The prevalence of microdontia, hypodontia, abnormally shaped teeth, and DDE was 17.5% (21), 5% (6), 8.33% (10), and 37.5% (45), respectively in CCS group. It was 8.2% (10), 2.5% (3), 1.65% (2), and 22.3% (27), respectively in the control group. A statistically significant difference was seen in microdontia (p = 0.032), abnormally shaped teeth (p = 0.017) and DDE (p = 0.01). Higher prevalence was seen when ACT began at an early age.

CONCLUSION

An association between developmental dental anomalies and anticancer therapy (ACT) exists with significantly higher difference in microdontia, abnormally shaped teeth and DDE among survivors of childhood cancer as compared to healthy population. These known adverse effects of ACT on developing teeth should be considered during treatment planning of the children having cancers.

Epidemiology and treatment of head and neck malignancies in the AYA generation

The Adolescent and Young Adult (AYA) population refers to the population of young adults and adolescents in the 15-39 years age group. This population subgroup experiences various important life events. Head and neck malignancies are rare tumors, in general, but they are extremely rare in the AYA population. When analyzed by the primary site of the tumors, thyroid gland, soft tissue, and nasopharyngeal malignancies are the most commonly encountered head and neck malignancies in the AYA generation. The most common histopathologic subtypes are carcinomas (thyroid carcinoma, nasopharyngeal carcinoma) and rhabdomyosarcoma. Therefore, in this review, the author discusses these three diseases in the AYA population in detail. Especially, patients with parameningeal rhabdomyosarcoma are at a high risk of dysfunction and facial deformity. Infertility problems may also occur as long-term sequelae of chemotherapy in this population. Radiation therapy might be associated with considerable morbidity. Complications such as cataract, xerostomia, hearing loss, neck fibrosis, and trismus are also common. Head and neck surgeons and medical oncologists should choose the optimal treatment taking into account the curability of the tumors relative to the long-term adverse events of treatment use. Finally, little evidence has been accumulated on head and neck malignancies in the AYA population, and it is urgently necessary to build a high level of evidence for the future.

Factors and Mechanisms Involved in Acquired Developmental Defects of Enamel: A Scoping Review

BACKGROUND

Developmental Defects of Enamel (DDE) is a pathology of the teeth that can greatly alter the quality of life of patients (hypersensitivity, esthetic issues, loss of function, etc.). The acquired DDE may occur as a result of a wide range of acquired etiological factors and his prevalence of this pathology may reach up to 89.9%. The main objective of this research was to identify and analyze, in current literature, the factors related to acquired DDE, in order to propose a general theory about the mechanisms involved.

METHODS

The search of the primary literature was conducted until [December 31, 2021]. Our search strategy uses the Pubmed/MEDLINE database and was structured around 3 terms ["Development," "Defect," and "Enamel"]. To be included, references had to be primary studies, written in English. Exclusion criteria were reviews, in vitro, animal, genetic or archeology studies, and studies focused on clinical management of DDE. One hundred and twenty three articles were included in this scoping review: 4 Randomized clinical trials, 1 letter, 5 cases reports, 2 fundamentals studies, and 111 observational studies (33 Cross-sectional studies, 68 Cohort study and 10 Case-control study). The quality of evidence was assessed using the PEDro scale for clinical trials, the Newcastle-Ottawa scale for observational studies, and a published tool to assess the quality of case reports and case series.

RESULTS

A scoping review of the literature identified 114 factors potentially involved in acquired DDE. The most frequently encountered pathologies are those causing a disorder of calcium homeostasis or a perturbation of the ARNT pathway in mother or child. The link between the ARNT pathway and metabolism deficiency in uncertain and needs to be defined. Also, the implication of this mechanism in tissue impairment is still unclear and needs to be explored.

CONCLUSIONS

By identifying and grouping the risk factors cited in the literature, this taxonomy and the hypotheses related to the mechanism allow health practitioners to adopt behaviors that limit the risk of developing aDDE and to set up a prevention of dental pathology. In addition, by reviewing the current literature, this work provides guidance for basic research, clinical studies, and literature searches.

Head and neck radiotherapy-induced changes in dentomaxillofacial structures detected on panoramic radiographs: A systematic review

Purpose

This study aimed to summarize the impact of neck and head radiation treatment on maxillofacial structures detected on panoramic radiographs.

Materials and Methods

In this systematic review, the authors searched PubMed Central, Embase, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and Google Scholar for original research studies up to February 2020 that included the following Medical Subject Headings keywords: words related to “radiotherapy” and synonyms combined with keywords related to “panoramic radiography” and “oral diagnosis” and synonyms. Only original studies in English that investigated the maxillofacial effects of radiotherapy via panoramic radiographs were included. The quality of the selected manuscripts was evaluated by assessing the risk of bias using Cochrane's ROBINS-I tool for non-randomized studies.

Results

Thirty-three studies were eligible and included in this review. The main objectives pertained to the assessment of the effects of radiation on maxillofacial structures, including bone architecture alterations, periodontal space widening, teeth development abnormalities, osteoradionecrosis, and implant bone loss. The number of participants evaluated ranged from 8 to 176.

Conclusion

The interaction between ionizing radiation and maxillofacial structures results in hazard to the tissues involved, particularly the bone tissue, periosteum, connective tissue of the mucosa, and endothelium. Hard tissue changes due to radiation therapy can be detected on panoramic radiographs.

Radiation Therapy in the Treatment of Head and Neck Rhabdomyosarcoma

The use of radiation therapy is an important part of multimodality treatment for rhabdomyosarcoma. The specific doses, treatment volumes, and techniques used in radiation therapy can vary dramatically based upon a number of factors including location, tumor size, and molecular characteristics, resulting in complex decisions in treatment planning. This article reviews the principles of evaluation and management for head and neck rhabdomyosarcoma including a summary of the historical studies upon which current management is based.

Mandibular metastases in neuroblastoma: Outcomes and dental sequelae

BACKGROUND

Although metastatic involvement of bony sites including cranial bones is common in neuroblastoma (NB), mandibular metastases (MM) are uncommon, and specific outcomes have not been reported upon in the modern therapeutic era.

METHODS

In this retrospective study, medical records on patients with MM from NB were reviewed. Statistical analysis was performed using the Kaplan-Meier method.

RESULTS

Of 29 patients, nine (31%) had MM at diagnosis, whereas in 20 (69%) MM were first detected at NB relapse at a median time of 26 (6-89) months from diagnosis. Median maximal diameter of lesions was 3 (range 0.8-4.9) cm. MM were unilateral in 83% of patients, with ascending ramus (55%) and mandibular body (38%) being the two most common sites. All patients received systemic chemotherapy, and 26 (93%) patients received radiotherapy to MM. At a median follow-up of 37.3 (24.2-219.5) months, eight of nine patients with MM at diagnosis did not experience mandibular progressive disease. Eighteen of 20 patients with MM at relapse received therapeutic radiotherapy; objective responses were noted in 78%. Seventy-two percent (5/18) had not experienced relapse within the radiation field at a median of 12 (2-276) months postradiotherapy. Dental findings at follow-up after completion of NB therapy included hypodontia, hypocalcification of enamel, and trismus. Median 3-year overall survival in patients with relapsed MM was 51 ± 12% months from relapse.

CONCLUSION

MM when detected at diagnosis is associated with a prognosis similar to that for other skeletal metastases of NB. Radiotherapy is effective for control of MM detected both at diagnosis and relapse. Significant dental abnormalities posttherapy warrant regular dental evaluations and appropriate intervention.

Efficacy of surgery combined with postoperative 125 I interstitial brachytherapy for treatment of acinic cell carcinoma of the parotid gland in children and adolescents

BACKGROUND

Acinic cell carcinoma (AciCC) is rare in children; therefore, reaching a consensus on its management is challenging and radiotherapy is limited by concerns about long-term toxicity. The purpose of this study is to analyze the effectiveness and safety of surgery plus postoperative ¹²⁵ I interstitial brachytherapy (IBT) for children and adolescents with AciCC of the parotid gland (PG) treated at a single institution.

PROCEDURE

Sixteen patients ≤ 18 years old with AciCC of the PG treated with surgery plus ¹²⁵ I IBT from 2007 to 2018 were included. Surgery was the primary treatment; ten patients underwent total gross excision and six subtotal gross excision. The matched peripheral dose was 60-120 Gy. Overall survival, disease-free survival (DFS), local control rate, distant metastasis, and radiation-associated toxicities were analyzed, and factors influencing outcomes were evaluated.

RESULTS

During follow-up (1.8-12.6 years; mean, 6.3 years), lymph node metastasis was observed in one case, 2.6 years after ¹²⁵ I IBT treatment. The five-year overall and DFS rates were 100% and 91.7%, respectively. On univariate analysis, tumor size ≥ 3 cm (100% vs 50%; P = 0.025) and extraglandular extension (100% vs 50%; P = 0.025) were significant prognostic indicators for DFS. No severe radiation-associated complications occurred.

CONCLUSIONS

Children and adolescents with AciCC of the PG with high-risk features can be managed using surgery plus postoperative ¹²⁵ I IBT with excellent local control. Radiation-related complications were minor. Patients with facial nerve involvement can have their facial nerves preserved. Residual tumors can be safely managed using adjuvant ¹²⁵ I IBT.

45 GyRBE for group III orbital embryonal rhabdomyosarcoma

Purpose: Despite widespread concerns of radiotherapy toxicity in children with head and neck tumors, recent Children's Oncology Group (COG) findings suggest that the use of 45 Gy results in an unacceptably high rate of local recurrences in patients with low-risk orbital rhabdomyosarcoma. We therefore evaluated outcomes in our pediatric patients who received 45 GyRBE using proton therapy. Material and methods: To assess disease control and toxicity, we reviewed the medical records of 30 children (≤21 years old) with COG stage 1, group III embryonal orbital rhabdomyosarcoma enrolled on a prospective outcome study and treated with proton therapy between 2007 and 2018. Results: Median age at the time of radiation was 4.8 years old. Twenty-one and nine patients received ifosfamide- and cyclophosphamide-based chemotherapy according to their respective cooperative group regimens. Median duration between the start of induction chemotherapy and radiation was 12 weeks. Two patients had a complete response to induction chemotherapy and two had stable disease. Twenty-six patients had a partial response to induction chemotherapy, with a median volume reduction of 66%. With a median follow-up of 4.0 years (range, 0.5-9.5 years), we observed 1 local failure 6 months following treatment in a patient who had a partial response to cyclosphophomide-based induction chemotherapy. The 5-year local control, progression-free survival, and overall survival rates were 97%, 97%, and 100%, respectively. Serious late toxicities included 18 patients with cataracts, 4 with exposure keratoconjunctivitis resulting in permanently reduced visual acuity, and 1 with chronic sinusitis. Conclusion: 45 GyRBE offers effective local control for most patients with group III orbital rhabdomyosarcoma. The delivery of proton therapy to the postinduction tumor volume plus a small margin can mitigate early- and intermediate-term toxicity, but side effects still occur and long-term data are needed to demonstrate the dosimetric advantage of proton therapy.

Late effects of chemo and radiation treatment on dental structures of childhood cancer survivors. A systematic review and meta-analysis

BACKGROUND

This systematic review summarizes the prevalence of dental defects after chemo and radiation therapy and correlates the findings with specific characteristics of each treatment modality.

METHODS

Database search was performed for studies reporting dental late effects of chemo and radiation therapy. After data extraction and risk of bias assessment, prevalence of crown and root defects was assessed. Correlations between each defect and the characteristics of the antineoplastic treatment were performed.

RESULTS

Sixteen nonrandomized studies were included, yielding a total of 1300 patients with a mean age at diagnosis of 4.5 years. Results reported that root defects were more common than crown defects. The most common root defect was impaired root growth and microdontia the most common crown defect. Age, radiation dose and field were statistically associated with higher prevalence of dental defects.

CONCLUSION

Defects were associated with combination of chemotherapy and radiotherapy, as used in current therapeutic antineoplastic modalities.

Pediatric Salivary Cancer: Epidemiology, Treatment Trends, and Association of Treatment Modality with Survival

Objective To characterize the epidemiology of pediatric salivary cancer and associate patient, tumor, and treatment factors with treatment modality and survival. Study Design Cross-sectional analysis. Setting US national database. Subjects and Methods We identified 588 patients 19 years or younger diagnosed with salivary cancer in the National Cancer Database 2004-2013. We characterized patient, tumor, and treatment factors as proportions and associated these factors with treatment modality and overall survival via multivariable logistic regression and multivariable Cox proportional hazards regression, respectively. Results In total, 588 patients were included. Mucoepidermoid carcinoma was identified in 234 of 588 patients (40%) and acinar cell carcinoma in 215 of 588 (37%). Parotid tumors were seen in 504 (86%) of patients. Surgery alone was used to treat 351 (60%) of patients; surgery plus adjuvant radiation was used to treat 145 (25%). Overall 5-year survival was 93%. Controlling for patient and tumor characteristics, treatment with surgery and radiation vs surgery alone was associated with improved overall survival (hazard ratio [HR] = 0.15; 95% confidence interval [CI], 0.02-0.92; P = .041). High tumor grade was associated with decreased overall survival (HR = 33.17; 95% CI, 5.89-186.8; P < .001). Treatment with surgery plus radiation remained associated with improved overall survival in the subset of patients with high tumor grade (HR = 0.12; 95% CI, 0.02-0.64; P = .014). Conclusion Tumor grade is an important predictor of survival in pediatric patients with salivary gland cancer. Surgery plus adjuvant radiation vs surgery alone is associated with improved overall survival and may be considered for high-risk patients, particularly those with high-grade tumors.

Clinicopathological analysis of head and neck rhabdomyosarcoma: A series of 10 cases and literature review

Background

To describe the clinicopathological characteristics of a series of head and neck rhabdomyosarcoma (RMS) and to review the literature.

Material and Methods

Cases diagnosed as RMS affecting the head and neck region were retrospectively retrieved from the files of two Brazilian institutions from January 2006 to January 2017. Data on clinical features (sex, age and affected site), microscopic subtype, immunohistochemical results, treatment employed and follow-up status were obtained from the patient’s medical charts.

Results

During the period considered, 10 cases of RMS were identified. Females predominated (4M:6F), the mean age at diagnosis was 16.5 years-old and the orbit was the most affected site (4 cases). Microscopically, most cases were classified as embryonal RMS (6 cases) and the Desmin/Myogenin/Myo-D1 immunohistochemical positivity was useful to confirm the diagnosis. Chemotherapy and radiotherapy were applied to 9 and 8 patients respectively, whereas 2 patients were treated by surgery. Recurrences occurred in 3 patients and distant metastasis in 2 cases. Nine patients were alive in their last follow-up, 3 of them with disease, whereas 1 patient died due to the disease.

Conclusions

Head and neck RMS is an aggressive malignant neoplasm which demands especial concern to achieve early diagnosis and successful treatment.

Key words:Rhabdomyosarcoma, soft tissue tumors, head and neck, oral cavity, chemotherapy.

Rhabdomyosarcoma, Spindle Cell/Sclerosing Variant: A Clinical and Histopathological Examination of this Rare Variant with Three New Cases from the Oral Cavity

Spindle cell/sclerosing rhabdomyosarcoma (S-ScRMS) was recently recognized in 2013 by the World Health Organization (WHO) as a stand-alone entity (Parham et al., WHO classification of tumours of soft tissue and bone, IARC Press, Lyon, 2013). Historically, the spindle cell and sclerosing variants were subcategorized under embryonal type rhabdomyosarcoma. Current data supports that certain S-ScRMS cases have a more aggressive clinical course with reduction of long-term survival, and those found in the head and neck region often exhibit extensive local recurrence. Furthermore, due to variable histopathologic appearances and immunohistochemical findings, misdiagnosis is common. We aim to report the variability in histopathologic patterns, immunohistochemical findings, radiographic features, and clinical data on three new cases of S-ScRMS presenting in the oral cavity of young adult males (ages 22, 24, and 39 years). The English-language literature on S-ScRMS is briefly reviewed as well.

Analysis of patient outcomes following proton radiation therapy for retinoblastoma

PURPOSE

Proton radiotherapy (PRT) is used in the treatment of retinoblastoma (RB) and has the potential to minimize exposure of normal tissue to radiation and thus decrease risk of toxicity and second malignancies. However, comprehensive analyses of long-term patient outcomes are not available.

METHODS

RB patients treated with PRT at our institution between 1986 and 2012 were invited to return for participation in a study designed to assess long-term outcomes. Enrolled patients underwent comprehensive analysis including oncologic, ophthalmic, endocrine, cephalometric, and quality of life (QOL) assessments.

RESULTS

A total of 12 patients were enrolled in this study, and the average length of follow-up among enrolled patients was 12.9 years (range 4.8-22.2 years). All enrolled patients had bilateral disease, and the disease and visual outcomes for enrolled patients were similar to outcomes for all RB patients treated with PRT over the same time period at our institution. Endocrine evaluation revealed no growth abnormalities or hormonal deficiencies across the cohort. Based on MRI and external cephalometry, PRT was associated with less facial hypoplasia than enucleation. Patient and parent-proxy QOL assessments revealed that RB treatment did not appear to severely impact long-term QOL.

CONCLUSIONS

In addition to providing an opportunity for long-term disease control and functional eye preservation, PRT does not appear to be associated with unexpected late visual, endocrine, or QOL effects in this cohort.