Radiation dose, chemotherapy and risk of osteosarcoma after solid tumours during childhood

Graphene Oxide (GO) for the Treatment of Bone Cancer: A Systematic Review and Bibliometric Analysis

Cancer is a severe disease that, in 2022, caused more than 9.89 million deaths worldwide. One worrisome type of cancer is bone cancer, such as osteosarcoma and Ewing tumors, which occur more frequently in infants. This study shows an active interest in the use of graphene oxide and its derivatives in therapy against bone cancer. We present a systematic review analyzing the current state of the art related to the use of GO in treating osteosarcoma, through evaluating the existing literature. In this sense, studies focused on GO-based nanomaterials for potential applications against osteosarcoma were reviewed, which has revealed that there is an excellent trend toward the use of GO-based nanomaterials, based on their thermal and anti-cancer activities, for the treatment of osteosarcoma through various therapeutic approaches. However, more research is needed to develop highly efficient localized therapies. It is suggested, therefore, that photodynamic therapy, photothermal therapy, and the use of nanocarriers should be considered as non-invasive, more specific, and efficient alternatives in the treatment of osteosarcoma. These options present promising approaches to enhance the effectiveness of therapy while also seeking to reduce side effects and minimize the damage to surrounding healthy tissues. The bibliometric analysis of photothermal and photochemical treatments of graphene oxide and reduced graphene oxide from January 2004 to December 2022 extracted 948 documents with its search strategy, mainly related to research papers, review papers, and conference papers, demonstrating a high-impact field supported by the need for more selective and efficient bone cancer therapies. The central countries leading the research are the United States, Iran, Italy, Germany, China, South Korea, and Australia, with strong collaborations worldwide. At the same time, the most-cited papers were published in journals with impact factors of more than 6.0 (2021), with more than 290 citations. Additionally, the journals that published the most on the topic are high impact factor journals, according to the analysis performed, demonstrating the high impact of the research field.

Subsequent primary neoplasms after childhood cancer therapy - design and description of the German nested case-control study STATT-SCAR

BACKGROUND

Subsequent primary neoplasms (SPN) are among the most severe late effects and the second most frequent cause of death in childhood cancer patients. In this paper we introduce method and properties of the STATT-SCAR study (Second Tumor After Tumor Therapy, Second Cancer After Radiotherapy), which is a joint nested matched case-control study to evaluate the impact of chemotherapy (STATT) as well as radiotherapy (SCAR) on the risk of developing a SPN.

METHODS

Based on the cohort of the German childhood cancer registry (GCCR), we selected patients diagnosed with a first neoplasm before age 15 or younger between 1980 and 2014. We selected those with a SPN at least half a year after the first neoplasm, and matched up to four controls to each case. Therapy data were acquired from various sources, including clinical study centers and treating hospitals. To analyze the impact of radiotherapy, organ doses were estimated by using reconstructed treatment plans. The effect of chemotherapy was analyzed using substance groups summarized after isotoxic dose conversion.

RESULTS

1244 cases with a SPN were identified and matched with 4976 controls. Treatment data were acquired for 83% of all match groups (one case and at least one control). Based on preliminary analyses, 98% of all patients received chemotherapy and 54% of all patients were treated with radiotherapy.

CONCLUSIONS

Based on our data, detailed analyses of dose response relationships and treatment element combinations are possible, leading to a deeper insight into SPN risks after cancer treatments.

TRIAL REGISTRATION

The study is registered at the German clinical trial register (DRKS) under number DRKS00017847 [45].

Risk Factors for Primary Bone Cancer After Childhood Cancer: A PanCare Childhood and Adolescent Cancer Survivor Care and Follow-Up Studies Nested Case-Control Study

PURPOSE

Radiation to the bone and exposure to alkylating agents increases the risk of bone cancer among survivors of childhood cancer, but there is uncertainty regarding the risks of bone tissue radiation doses below 10 Gy and the dose-response relationship for specific types of chemotherapy.

METHODS

Twelve European countries contributed 228 cases and 228 matched controls to a nested case-control study within a cohort of 69,460 5-year survivors of childhood cancer. Odds ratios (ORs) of developing bone cancer for different levels of cumulative radiation exposure and cumulative doses of specific types of chemotherapy were calculated. Excess ORs were calculated to investigate the shape and extent of any dose-response relationship.

RESULTS

The OR associated with bone tissue exposed to 1-4 Gy was 4.8-fold (95% CI, 1.2 to 19.6) and to 5-9 Gy was 9.6-fold (95% CI, 2.4 to 37.4) compared with unexposed bone tissue. The OR increased linearly with increasing dose of radiation (Ptrend < .001) up to 78-fold (95% CI, 9.2 to 669.9) for doses of ≥40 Gy. For cumulative alkylating agent doses of 10,000-19,999 and ≥20,000 mg/m2, the radiation-adjusted ORs were 7.1 (95% CI, 2.2 to 22.8) and 8.3 (95% CI, 2.8 to 24.4), respectively, with independent contributions from each of procarbazine, ifosfamide, and cyclophosphamide. Other cytotoxics were not associated with bone cancer.

CONCLUSION

To our knowledge, we demonstrate-for the first time-that the risk of bone cancer is increased 5- to 10-fold after exposure of bone tissue to cumulative radiation doses of 1-9 Gy. Alkylating agents exceeding 10,000 mg/m2 increase the risk 7- to 8-fold, particularly following procarbazine, ifosfamide, and cyclophosphamide. These substantially elevated risks should be used to develop/update clinical follow-up guidelines and survivorship care plans.

Equivalent doses for anticancer agents used in pediatric oncology: A literature review and evaluation of a novel approach for conversion factors

BACKGROUND

Epidemiological research on late effects of therapy shows the necessity to aggregate chemotherapy agents to substance classes. This requires using conversion factors by substance classes.

AIMS

The aim of this study was to identify previously used conversion factors from the literature, to present a novel approach for additional factors, and to compare these approaches.

METHODS AND RESULTS

A literature review was performed, which identified two main principles of deriving conversion factors: effect-equivalence and equimolar. Thirty-five articles presenting effect equivalence-based factors in the widest sense were found in the literature. Ten articles presented the equimolar approach which can be applied to almost all chemotherapy substances. Based on a comprehensive list of treatment protocols used in German pediatric oncology, we derived alternative conversion factors from typical doses. We compared the conversion factors using Pearson correlation coefficients and linear regression. At least two types of conversion factor were available for each of the 49 substances included. The equivalent effect-based and the typical dose-based factors were highly correlated with a regression coefficient close to 1. The equimolar factors are independent.

CONCLUSIONS

For substances for which no conversion factor based on some type of effect equivalence has been published so far, a factor based on a typical doses-approach may be used in epidemiological late effects research. Doses aggregated based on the equimolar approach may not be compatible with doses aggregated based on equivalent effects.

Treatment of Osteoporosis With Anabolic Agents and the Risk of Primary Bone Cancers: A Study of 44,728 Patients Treated With Teriparatide and Abaloparatide

INTRODUCTION

Bone anabolic agents can benefit orthopaedic patients perioperatively and improve outcomes after fragility fractures. However, preliminary animal data raised concern for the potential development of primary bony malignancies after treatment with these medications.

METHODS

This investigation examined 44,728 patients older than 50 years who were prescribed teriparatide or abaloparatide and compared them with a matched control group to evaluate risk of primary bone cancer development. Patients younger than 50 years with a history of cancer or other risk factors of bony malignancy were excluded. A separate cohort of 1,241 patients prescribed an anabolic agent with risk factors of primary bone malignancy, along with 6,199 matched control subjects, was created to evaluate the effect of anabolic agents. Cumulative incidence and incidence rate per 100,000 person-years were calculated as were risk ratios and incidence rate ratios.

RESULTS

The overall risk of primary bone malignancy development for risk factor-excluded patients in the anabolic agent-exposed group was 0.02%, compared with 0.05% in the nonexposed group. The incidence rate per 100,000 person-years was calculated at 3.61 for the anabolic-exposed patients and 6.46 for control subjects. A risk ratio of 0.47 (P = 0.03) and incidence rate ratio of 0.56 (P = 0.052) were observed for the development of primary bone malignancies in patients undergoing treatment with bone anabolic agents. Among high-risk patients, 5.96% of the anabolic-exposed cohort developed primary bone malignancies and 8.13% of nonexposed patients developed primary bone malignancy. The risk ratio was 0.73 (P = 0.01), and the incidence rate ratio was 0.95 (P = 0.67).

CONCLUSION

Teriparatide and abaloparatide can safely be used for osteoporosis and orthopaedic perioperative management without increased risk of development of primary bone malignancy.

Radiation-induced sarcoma of head and neck: Clinical characteristics and molecular signatures

BACKGROUND

Radiation-induced sarcoma of the head and neck (RISHN) is a rare yet devastating potential complication of radiotherapy treatment. We aimed to evaluate the clinicopathological characteristics and molecular signatures of RISHN in patients who underwent radiotherapy for head and neck cancer (HNC) to identify high-risk patients and enable earlier cancer detection.

METHODS

This study retrospectively evaluated 24 sarcoma patients who received radiotherapy for HNC between 1994 and 2019. Patients were divided into two groups based on RISHN latency period. Patient demographics, initial tumor staging, risk factors, and survival between groups were analyzed, and whole-exome sequencing (WES) of selected samples was performed.

RESULTS

The median age at diagnosis of RISHN was 54 years, and the male-to-female ratio was 2:1. The latency period ranged from 0.8 to 64.4 years (median 6.5 years), with a median survival of 21.5 months. Primary cancer in the oral cavity, treatment with alkylating agents, alcohol consumption, betel nut chewing, and smoking were identified as risk factors for short (<5 years) latency periods. The majority of RISHN cases occurred in the oral cavity (58.3%). WES analysis showed that tumor necrosis factor and cell cycle checkpoint pathways were differentially involved in both patient groups.

CONCLUSIONS

Although case numbers were small, our cohort represents the largest case series of RISHN from a single institution to date. Clinicians must be aware of factors affecting RISHN development and latency, and risk factor identification may lead to earlier detection and prevention in the future.

Incidence of second primary cancers among survivors of childhood cancer: A population-based study, Osaka, Japan, 1975-2015

Second primary cancer (SPC) is one of the most life-threatening late effects of childhood cancers. We investigated the incidence and survival outcomes of SPC in childhood cancer patients in Japan. Data were obtained from the population-based Osaka Cancer Registry. Individuals diagnosed with cancer at age 0-14 years during 1975-2014 and survived 2 months or longer were followed through December 2015. The risk of developing SPC was assessed with standardized incidence ratio (SIR), excess absolute risk (EAR, per 100,000 person-years), and cumulative incidence. Multivariable Poisson regression analysis was carried out to assess relative risks of SPC by treatment method. Survival analysis was undertaken using the Kaplan-Meier method. Of 7229 childhood cancer survivors, 101 (1.4%) developed SPC after a median of 11.6 years. Overall SIR was 5.0, which corresponded with 84.3 EAR. The cumulative incidence was 0.9%, 2.1%, and 3.4% at 10, 20, and 30 years, respectively. Among all SPCs, the type that contributed most to the overall burden was cancers in the central nervous system (EAR = 28.0) followed by digestive system (EAR = 15.1), thyroid (EAR = 8.3), and bones and joints (EAR = 7.8); median latency ranged from 2.0 years (lymphomas) to 26.6 years (skin cancers). Patients treated with radiotherapy alone were at a 2.58-fold increased risk of developing SPC compared to those who received neither chemotherapy nor radiotherapy. Among patients who developed SPCs, 5-year and 10-year survival probabilities after SPC diagnosis were 61.7% and 52.0%, respectively. Risk-based long-term follow-up planning is essential to inform survivorship care and help reduce the burden of SPCs in childhood cancer survivors.

Ultra-Late Osteosarcoma Recurrences: An Analysis of 17 Cooperative Osteosarcoma Study Group Patients with a First Recurrence Detected More Than 10 Years After Primary Tumor Diagnosis

Purpose: Osteosarcoma is a typical malignancy of childhood and adolescence. Recurrences usually occur early, but rarely may arise after decades of remission. Little is known about these very late events and we set out to fill this knowledge gap. Methods: The database of the Cooperative Osteosarcoma Study Group (COSS) was searched for patients with a first recurrence of a high-grade central osteosarcoma occurring >10 years after diagnosis of the primary disease. Identified patients were analyzed for demographic, tumor-, and treatment-related factors as well as outcomes. Results: Among a total of 1,178 10-year relapse-free survivors, 17 affected patients were identified. Only five of these had a documented good response to initial chemotherapy. No presenting factor was identified to predict these very late events. Prognosis was generally very poor despite intensive multimodal therapy. Inoperability of the recurrences seems to have constituted a major limiting factor. Conclusion: Osteosarcoma patients should be followed for potential recurrences for well >10 years from initial diagnosis. Only through such an extended truly long-term follow-up and a structured transition of young patients can these be detected while they are still operable and, hence, potentially curable.

Towards the Search for Potential Biomarkers in Osteosarcoma: State-of-the-Art and Translational Expectations

Osteosarcoma represents a rare cause of cancer in the general population, accounting for <1% of malignant neoplasms globally. Nonetheless, it represents the main cause of malignant bone neoplasm in children, adolescents and young adults under 20 years of age. It also presents another peak of incidence in people over 50 years of age and is associated with rheumatic diseases. Numerous environmental risk factors, such as bone diseases, genetics and a history of previous neoplasms, have been widely described in the literature, which allows monitoring a certain group of patients. Diagnosis requires numerous imaging tests that make it possible to stratify both the local involvement of the disease and its distant spread, which ominously determines the prognosis. Thanks to various clinical trials, the usefulness of different chemotherapy regimens, radiotherapy and surgical techniques with radical intent has now been demonstrated; these represent improvements in both prognosis and therapeutic approaches. Osteosarcoma patients should be evaluated in reference centres by multidisciplinary committees with extensive experience in proper management. Although numerous genetic and rheumatological diseases and risk factors have been described, the use of serological, genetic or other biomarkers has been limited in clinical practice compared to other neoplasms. This limits both the initial follow-up of these patients and screening in populations at risk. In addition, we cannot forget that the diagnosis is mainly based on the direct biopsy of the lesion and imaging tests, which illustrates the need to study new diagnostic alternatives. Therefore, the purpose of this study is to review the natural history of the disease and describe the main biomarkers, explaining their clinical uses, prognosis and limitations.

Canine and murine models of osteosarcoma

Osteosarcoma (OS) is the most common malignant bone tumor in children. Despite efforts to develop and implement new therapies, patient outcomes have not measurably improved since the 1980s. Metastasis continues to be the main source of patient mortality, with 30% of cases developing metastatic disease within 5 years of diagnosis. Research models are critical in the advancement of cancer research and include a variety of species. For example, xenograft and patient-derived xenograft (PDX) mouse models provide opportunities to study human tumor cells in vivo while transgenic models have offered significant insight into the molecular mechanisms underlying OS development. A growing recognition of naturally occurring cancers in companion species has led to new insights into how veterinary patients can contribute to studies of cancer biology and drug development. The study of canine cases, including the use of diagnostic tissue archives and clinical trials, offers a potential mechanism to further canine and human cancer research. Advancement in the field of OS research requires continued development and appropriate use of animal models. In this review, animal models of OS are described with a focus on the mouse and tumor-bearing pet dog as parallel and complementary models of human OS.

Osteosarcoma: a Surveillance, Epidemiology, and End Results program-based analysis from 1975 to 2017

BACKGROUND

Osteosarcoma is the most common primary bone malignancy. As a rare cancer, population-based studies remain small with limited information on finer demographic categories. Recent studies have reported important genetic differences based on age and ethnicity, and more detailed studies are needed to better understand potentially important osteosarcoma risk groups.

METHODS

Incidence and survival rates for 5016 patients with osteosarcoma from the Surveillance, Epidemiology, and End Results (SEER) program (1975-2017) were analyzed by age (0-9, 10-24, 25-59, and >60 years old), race/ethnicity, histologic subtype, stage, and tumor location using SEER*Stat software.

RESULTS

For cases 0 to 9 years old, incidence of primary osteosarcoma was similar between the sexes, increased significantly throughout the study period (P < .05), and the 5-year relative survival has steadily increased over time. Blacks had the highest incidence in all aged cases combined and a significant increase in incidence throughout the study period (P < .05). Overall, survival rates for all cases have remained relatively unchanged over recent decades, with worse survival observed in males, American Indian/Alaska Native cases, older patients, metastatic disease, axial tumors, and subsequent osteosarcoma cases. For cases 0 to 24 years old, the incidence of subsequent osteosarcoma increased 3-fold since the 2000s.

CONCLUSION

Important differences in osteosarcoma incidence and survival, particularly for the youngest children, ethnic minorities, and subsequent osteosarcoma, are identified. A genetic risk factor may be associated with observed ancestry-specific incidence differences and illustrates the importance of analyzing osteosarcoma by specific age groups and ethnicities to better understand their unique epidemiology and underlying biology.

LAY SUMMARY

Osteosarcoma is the most common bone cancer, but still a relatively rare disease, and previous studies have had limited information on finer demographics. Using a large database, osteosarcoma incidence and survival patterns are thoroughly evaluated and important differences, especially for the youngest children, ethnic minorities, and subsequent osteosarcoma cases, are identified.

Osteoid Tumors of Bone

We present a review of several bone (osteoid)-forming tumors including enostosis, osteoid osteoma, osteoblastoma, and osteosarcoma. These entities were chosen because they are reasonably common-neither seen every day nor rare. When applicable, recent information about the lesions is included.

Allelic Expression Imbalance Analysis Identified YAP1 Amplification in p53- Dependent Osteosarcoma

Simple Summary

Osteosarcoma (OS) is a highly heterogenous cancer, making the identification of genetic driving factors difficult. Genetic factors, such as heritable mutations of Rb1 and TP53, are associated with an increased risk of OS. We previously generated pigs carrying a mutated TP53 gene, which develop OS at high frequency. RNA sequencing and allelic expression imbalance analysis identified an amplification of YAP1 involved in p53- dependent OS progression. The inactivation of YAP1 inhibits proliferation, migration, and invasion, and leads to the silencing of TP63 and reconstruction of p16 expression in p53-deficient porcine OS cells. This study confirms the importance of p53/YAP1 network in cancer.

Abstract

Osteosarcoma (OS) is a primary bone malignancy that mainly occurs during adolescent growth, suggesting that bone growth plays an important role in the aetiology of the disease. Genetic factors, such as heritable mutations of Rb1 and TP53, are associated with an increased risk of OS. Identifying driver mutations for OS has been challenging due to the complexity of bone growth-related pathways and the extensive intra-tumoral heterogeneity of this cancer. We previously generated pigs carrying a mutated TP53 gene, which develop OS at high frequency. RNA sequencing and allele expression imbalance (AEI) analysis of OS and matched healthy control samples revealed a highly significant AEI (p = 2.14 × 10⁻³⁹) for SNPs in the BIRC3-YAP1 locus on pig chromosome 9. Analysis of copy number variation showed that YAP1 amplification is associated with the AEI and the progression of OS. Accordingly, the inactivation of YAP1 inhibits proliferation, migration, and invasion, and leads to the silencing of TP63 and reconstruction of p16 expression in p53-deficient porcine OS cells. Increased p16 mRNA expression correlated with lower methylation of its promoter. Altogether, our study provides molecular evidence for the role of YAP1 amplification in the progression of p53-dependent OS.

Subsequent Malignant Neoplasms in Retinoblastoma Survivors

Retinoblastoma (Rb) is a pediatric malignant eye tumor. Subsequent malignant neoplasms (SMNs) and trilateral Rb (TRb) are the leading cause of death in heritable Rb patients in developed countries. The high rate of SMNs in heritable Rb patients is attributed to the presence of a mutation in the RB1 tumor suppressor gene. In addition, Rb therapy choices also influence SMN incidence in this patient group. The incidence rates and age of occurrence for the most frequent SMNs and TRb will be discussed. In addition, the impact of genetic predisposition and Rb treatments on the development of SMNs will be evaluated. Furthermore, screening and other prevention methods will be reviewed.

Chitosan applications in studying and managing osteosarcoma

Osteosarcoma has a high prevalence among children and adolescents. Common treatments of this disease are not promising enough. Molecular processes involved in the pathogenesis of osteosarcoma are not fully understood. Besides, the remnants of tumor cells after surgery can cause bone destruction and recurrence of the disease. Thus, there is a need to develop novel drugs or enhancing the currently-used drugs as well as identifying bone-repairing methods. Chitosan is a natural compound produced by the deacetylation of chitin. Research has shown that chitosan can be used in various fields due to its beneficial effects, such as biodegradability and biocompatibility. Regarding cancer, chitosan exerts several anti-tumor activities. Moreover, it can be used in diagnostic techniques, drug delivery systems, and cell culture methods. Herein, we aim to discuss the potential roles of chitosan in studying and treating osteosarcoma. We review the literature on chitosan's applications as a drug delivery system and how it can be combined with other substances to improve its ability of local drug delivery. We take a look into the studies concerning the possible benefits of chitosan in the field of bone tissue engineering and 3D culturing. Furthermore, anti-cancer activities of different compounds of chitosan are reviewed.

Subsequent Primary Neoplasms: Risks, Risk Factors, Surveillance, and Future Research

The authors' objective is to provide a brief update on recent advances in knowledge relating to subsequent primary neoplasms developing in survivors of childhood cancer. This includes a summary of established large-scale cohorts, risks reported, and contrasts with results from recently established large-scale cohorts of survivors of adolescent and young adult cancer. Recent evidence is summarized concerning the role of radiotherapy and chemotherapy for childhood cancer and survivor genomics in determining the risk of subsequent primary neoplasms. Progress with surveillance, screening, and clinical follow-up guidelines is addressed. Finally, priorities for future research are outlined.

Theabrownin inhibits the cytoskeleton‑dependent cell cycle, migration and invasion of human osteosarcoma cells through NF‑κB pathway‑related mechanisms

Considering the high metastatic potential of osteosarcoma, not only pro-apoptosis, but also anti-metastasis is important for anti-osteosarcoma therapy. Previously, the authors reported the pro-apoptotic and tumor-inhibitory effects of theabrownin (TB) on osteosarcoma cells; however, its effects on the metastasis-related migration and invasion of osteosarcoma cells remain unknown. The present study conducted RNA sequencing (RNA-seq) on xenograft zebrafish samples and performed in vitro experiments, including RT-qPCR, cell viability analysis, clone formation assay, cell cycle analysis, immunofluorescence, cell migration assay, cell invasion assay, wound healing assay and western blot (WB) analysis to evaluate the anti-metastatic effects and mechanism of TB against osteosarcoma cells. The RNA-seq data revealed that TB significantly downregulated the expression of genes involved in the microtubule bundle formation of U2OS cells, which was verified by RT-qPCR. The cell viability and clone formation data indicated that TB significantly inhibited U2OS cell viability and colony numbers. The results of cell cycle analysis revealed the blocked cell cycle progression of U2OS by TB. The immunofluorescent data revealed an evident cytoskeleton-inhibitory effect of TB against the microfilament and microtubule formation of U2OS cells. The results of cell migration and invasion demonstrated that TB significantly inhibited U2OS cell migration and invasion. The results of WB analysis revealed that TB significantly regulated key molecules of epithelial-mesenchymal transition [EMT; e.g., E-cadherin, vimentin, Snail-1, Slug and zinc finger E-box-binding homeobox 1 (ZEB-1)] and those of the nuclear factor (NF)-κB pathway (e.g., NF-κB, phospho-IKKα and phospho-IKKβ), indicating that NF-κB pathway-related EMT suppression may mediate the mechanisms underlying the anti-migratory and anti-invasive effects of TB against osteosarcoma. To the best of our knowledge, this is the first study on the inhibitory effects and mechanisms of TB on the cytoskeleton-dependent cell cycle, migration and invasion of human osteosarcoma cells. The findings presented herein suggest that TB may be a promising anti-metastatic candidate for anti-osteosarcoma therapy.

Epidemiology and Risk Factors of Osteosarcoma

Osteosarcoma is a rare tumor diagnosed at any age; however younger age is a common risk factor. In addition, multiple factors are believed to contribute to higher rates of osteosarcoma, particularly race and gender. Although diagnosed worldwide, osteosarcoma is found to be more prevalent in Africa with high numbers of cases reported in Nigeria, Uganda, and Sudan. Additionally, higher rates are detected in African Americans, suggesting a genetic predisposition linked to race. This review focuses on identifying high risk factors of osteosarcoma with an emphasis on sarcoma epidemiology and risk factors in African countries.

Craniofacial second primary tumors in patients with germline retinoblastoma previously treated with external beam radiotherapy: A retrospective institutional analysis

BACKGROUND

The long-term survival of germline retinoblastoma patients is decreased due to the risk of second primary tumors (SPTs) that occur years after the diagnosis of retinoblastoma. This risk is related to genetic predisposition and other factors, such as the treatment of retinoblastoma by external beam radiotherapy (EBRT).

PROCEDURE

We studied the incidence, risk factors, and prognosis of specific craniofacial SPTs developed within the margins of radiation field in a cohort of 209 patients with germline retinoblastoma treated with EBRT at our institution between 1977 and 2010. Clinical characteristics, survival, incidence, and histology of craniofacial SPTs were recorded.

RESULTS

Fifty-three of the 209 patients developed 60 distinct craniofacial SPTs in irradiated field with a median time from EBRT of 16.9 years (4-35) and a median follow-up of 24.8 years (5.3-40). Osteosarcoma (33.3%) and undifferentiated sarcoma (23.3%) were the more prevalent histological entities. Benign tumors (16.7%) also occurred. The cumulative incidence of craniofacial SPTs reached 32.6% at 35 years after EBRT, and the median survival after diagnosis was five years. In our series, irradiation under 12 months of age, bilateral EBRT, or previous treatment of retinoblastoma with chemotherapy did not significantly increase the risk of craniofacial SPTs.

CONCLUSIONS

This work presents a strong argument to avoid EBRT in the management of retinoblastoma and emphasizes the high risk and poor prognosis of specific craniofacial SPTs. This study also points to the question of the need and benefits of special programs for early detection of craniofacial SPTs in survivors of irradiated germline retinoblastoma.

Risk of Second Primary Bone and Soft-Tissue Sarcomas Among Young Adulthood Cancer Survivors

Excess sarcoma risks after childhood cancer are well established, but risks among young adulthood cancer survivors are poorly understood. Using US population-based cancer registry data, we compared bone and soft-tissue sarcoma risk vs the general population among 186 351 individuals who were diagnosed with nonsarcoma first primary malignancies at ages 20-39 years from 1975 to 2014 (follow-up through 2015) and survived at least 1 year. Bone sarcomas were rare (n = 50), but risk was statistically significantly elevated overall (2.9-fold) and greater than fivefold after Hodgkin lymphoma, non-Hodgkin lymphoma, and central nervous system tumors. Soft-tissue sarcomas were more common (n = 284) and risks were statistically significantly elevated approximately twofold overall and after melanoma and carcinomas of the breast, thyroid, and testis, and greater than fourfold after Hodgkin lymphoma and central nervous system tumors. Risks varied markedly by subtype, with the highest risks (greater than fourfold) for osteosarcoma and the soft-tissue subtypes of rhabdomyosarcoma and blood vessel and nerve sheath sarcomas. These data demonstrate elevated risk for sarcoma after a range of young adulthood cancers.

Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin increases the activation of aryl hydrocarbon receptor and is associated with the aggressiveness of osteosarcoma MG-63 osteoblast-like cells

The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor whose activity is modulated by xenobiotics and physiological ligands. Activation of the AhR by environmental xenobiotics may induce a conformational change in AhR and has been implicated in a variety of cellular processes, including inflammation and tumorigenesis. It is unknown whether the activation of AhR serves a role in modulating the progression of osteosarcoma. The osteosarcoma cell line MG-63, was treated with AhR ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). TCDD treatment degrades AhR expression through activation of the AhR signaling pathway, however there were no survival differences observed in MG-63 cells. There were concomitant elevations of cyclooxygenase-2 and receptor activator of nuclear factor-κB ligand secretion from MG-63 cells upon TCDD treatment on a protein and mRNA level at 24 and 72 h. In addition, TCDD treatment also increases the production of prostaglandin E2 on MG-63 cells, and induces the expression of chemokine receptor CXCR4. However, CXCL12 production was not altered in MG-63 cells when stimulated with TCDD. The AhR antagonist CH-223191, blocks the effects on TCDD-induced RANKL, COX-2, PGE2 and CXCR4 changes. In conclusion, these findings suggest that AhR signal therapy should be further explored as a therapeutic option for the treatment of osteosarcoma.

Circulating biomarkers in osteosarcoma: new translational tools for diagnosis and treatment

Osteosarcoma (OS) is a rare primary malignant bone tumour arising from primitive bone-forming mesenchymal cells, with high incidence in children and young adults, accounting for approximately 60% of all malignant bone tumours. Currently, long-term disease-free survival can be achieved by surgical treatment plus chemotherapy in approximately 60% of patients with localized extremity disease, and in 20-30% of patients with metastatic lung or bone disease. Diagnosis of primary lesions and recurrences is achieved by using radiological investigations and standard tissue biopsy, the latter being costly, painful and hardly repeatable for patients. Therefore, despite some recent advances, novel biomarkers for OS diagnosis, prediction of response to therapy, disease progression and chemoresistance, are urgently needed. Biological fluids such as blood represent a rich source of non-invasive cancer biomarkers, which allow to understand what is really happening inside the tumour, either at diagnosis or during disease progression. In this regard, liquid biopsy potentially represents an alternative and non-invasive method to detect tumour onset, progression and response to therapy. In this review, we will summarize the state of the art in this novel area, illustrating recent studies on OS. Although the data reported in literature seem preliminary, liquid biopsy represents a promising tool with the potential to be rapidly translated in the clinical practice.

Extraskeletal osteosarcoma of the lung following treatment of primary small-cell lung carcinoma with chemoradiotherapy: A case report

Primary pulmonary osteosarcoma is a rare entity, with only a few cases reported in the literature to date. Moreover, secondary extraskeletal osteosarcoma of the lung following chemoradiotherapy is extremely rare and, to the best of our knowledge, this is the first reported case. We herein present the case of an 80-year-old male patient with small-cell lung cancer (SCLC), who developed what it was initially considered as recurrence of the tumor after chemoradiotherapy. The patient eventually succumbed to the disease, and on autopsy it was discovered that the lung tumor was not in fact SCLC, but rather a secondary osteosarcoma. Osteosarcoma metastasis to the lung is very rare, but must be considered in the differential diagnosis when there is relapse following treatment for primary SCLC.

Risk of Subsequent Bone Cancers Among 69 460 Five-Year Survivors of Childhood and Adolescent Cancer in Europe

Introduction

We investigate the risks of subsequent primary bone cancers after childhood and adolescent cancer in 12 European countries. For the first time, we satisfactorily address the risks beyond 40 years from diagnosis and beyond 40 years of age among all survivors.

Methods

This largest-ever assembled cohort comprises 69 460 five-year survivors of cancer diagnosed before age 20 years. Standardized incidence ratios, absolute excess risks, and multivariable-adjusted relative risks and relative excess risks were calculated. All statistical tests were two-sided.

Results

Overall, survivors were 21.65 times (95% confidence interval = 18.97 to 24.60 times) more likely to be diagnosed with a subsequent primary bone cancer than expected from the general population. The greatest excess numbers of bone cancers were observed after retinoblastoma, bone sarcoma, and soft tissue sarcoma. The excess number of bone cancers declined linearly with both years since diagnosis and attained age (all P < .05). Beyond 40 years from diagnosis and age 40 years, there were at most 0.45 excess bone cancers among all survivors per 10 000 person-years at risk; beyond 30 years from diagnosis and age 30 years, there were at most 5.02 excess bone cancers after each of retinoblastoma, bone sarcoma, and soft tissue sarcoma, per 10 000 person-years at risk.

Conclusions

For all survivors combined and the cancer groups with the greatest excess number of bone cancers, the excess numbers observed declined with both age and years from diagnosis. These results provide novel, reliable, and unbiased information about risks and risk factors among long-term survivors of childhood and adolescent cancer.

Germline and somatic genetics of osteosarcoma - connecting aetiology, biology and therapy

Clinical outcomes and treatment modalities for osteosarcoma, the most common primary cancer of bone, have changed very little over the past 30 years. The peak incidence of osteosarcoma occurs during the adolescent growth spurt, which suggests that bone growth and pubertal hormones are important in the aetiology of the disease. Tall stature, high birth weight and certain inherited cancer predisposition syndromes are well-described risk factors for osteosarcoma. Common genetic variants are also associated with osteosarcoma. The somatic genome of osteosarcoma is highly aneuploid, exhibits extensive intratumoural heterogeneity and has a higher mutation rate than most other paediatric cancers. Complex pathways related to bone growth and development and tumorigenesis are also important in osteosarcoma biology. In this Review, we discuss the contributions of germline and somatic genetics, tumour biology and animal models in improving our understanding of osteosarcoma aetiology, and their potential to identify novel therapeutic targets and thus improve the lives of patients with osteosarcoma.

Chemotherapy with radiotherapy influences time-to-development of radiation-induced sarcomas: a multicenter study

Background:

An increasing number and proportion of cancer patients with apparently localised disease are treated with chemotherapy and radiation therapy in contemporary oncology practice. In a pilot study of radiation-induced sarcoma (RIS) patients, we demonstrated that chemotherapy was associated with a reduced time to development of RIS. We now present a multi-centre collaborative study to validate this association.

Methods:

This was a retrospective cohort study of RIS cases across five large international sarcoma centres between 1 January 2000 to 31 December 2014. The primary endpoint was time to development of RIS.

Results:

We identified 419 patients with RIS. Chemotherapy for the first malignancy was associated with a shorter time to RIS development (HR 1.37; 95% CI: 1.08–1.72; P=0.009). In the multi-variable model, older age (HR 2.11; 95% CI 1.83–2.43; P<0.001) and chemotherapy for the first malignancy (HR 1.61; 95% CI 1.26–2.05; P<0·001) were independently associated with a shorter time to RIS. Anthracyclines and alkylating agents significantly contribute to the effect.

Conclusions:

This study confirms an association between chemotherapy given for the first malignancy and a shorter time to development of RIS.

Osteosarcoma Overview

Osteosarcoma (OS) is the most common primary malignancy of bone and patients with metastatic disease or recurrences continue to have very poor outcomes. Unfortunately, little prognostic improvement has been generated from the last 20 years of research and a new perspective is warranted. OS is extremely heterogeneous in both its origins and manifestations. Although multiple associations have been made between the development of osteosarcoma and race, gender, age, various genomic alterations, and exposure situations among others, the etiology remains unclear and controversial. Noninvasive diagnostic methods include serum markers like alkaline phosphatase and a growing variety of imaging techniques including X-ray, computed tomography, magnetic resonance imaging, and positron emission as well as combinations thereof. Still, biopsy and microscopic examination are required to confirm the diagnosis and carry additional prognostic implications such as subtype classification and histological response to neoadjuvant chemotherapy. The current standard of care combines surgical and chemotherapeutic techniques, with a multitude of experimental biologics and small molecules currently in development and some in clinical trial phases. In this review, in addition to summarizing the current understanding of OS etiology, diagnostic methods, and the current standard of care, our group describes various experimental therapeutics and provides evidence to encourage a potential paradigm shift toward the introduction of immunomodulation, which may offer a more comprehensive approach to battling cancer pleomorphism.

Prospective Preliminary In Vitro Investigation of a Magnetic Iron Oxide Nanoparticle Conjugated with Ligand CD80 and VEGF Antibody As a Targeted Drug Delivery System for the Induction of Cell Death in Rodent Osteosarcoma Cells

Target drug deliveries using nanotechnology are a novel consideration in the treatment of cancer. We present herein an in vitro mouse model for the preliminary investigation of the efficacy of an iron oxide nanoparticle complex conjugated to vascular endothelial growth factor (VEGF) antibody and ligand cluster of differentiation 80 (CD80) for the purpose of eventual translational applications in the treatment of human osteosarcoma (OSA). The 35 nm diameter iron oxide magnetic nanoparticles are functionalized with an n-hydroxysuccinimide biocompatible coating and are conjugated on the surface to proteins VEGF antibody and ligand CD80. Combined, these proteins have the ability to target OSA cells and induce apoptosis. The proposed system was tested on a cancerous rodent osteoblast cell line (ATCCTM^NPO CRL-2836) at four different concentrations (0.1, 1.0, 10.0, and 100.0 μg/mL) of ligand CD80 alone, VEGF antibody alone, and a combination thereof (CD80+VEGF). Systems were implemented every 24 h over different sequential treatment timelines: 24, 48, and 72 h, to find the optimal protein concentration required for a reduction in cell proliferation. Results demonstrated that a combination of ligand CD80 and VEGF antibody was consistently most effective at reducing aberrant osteoblastic proliferation for both the 24- and 72-h timelines. At 48 h, however, an increase in cell proliferation was documented for the 0.1 and 1 μg/mL groups. For the 24- and 72-h tests, concentrations of 1.0 μg/mL of CD80+VEGF and 0.1 μg/mL of VEGF antibody were most effective. Concentrations of 10.0 and 100.0 μg/mL of CD80+VEGF reduced cell proliferation, but not as remarkably as the 1.0 μg/mL concentration. In addition, cell proliferation data showed that multiple treatments (72-h test) induced cell death in the osteoblasts better than a single treatment. Future targeted drug delivery system research includes trials in OSA cell lines from greater phylum species having spontaneous OSA, such as the dog, and on a human OSA cell line model.

Osteosarcoma After Hematopoietic Stem Cell Transplantation in Children and Adolescents: Case Report and Review of the Literature

Osteosarcoma as a secondary malignancy after hematopoietic stem cell transplantation (HSCT) is very rare. We present a case and review of 18 other cases reported to date. Our patient underwent HSCT for myelodysplastic syndrome at the age of 4 years. She developed osteosarcoma 13 years later. She underwent surgery after three courses of neoadjuvant chemotherapy followed by chemotherapy and mifamurtide. She has no evidence of disease 28 months after termination of chemotherapy. In 18 other cases of secondary osteosarcoma in the literature, 15 had received total body irradiation, eight had received alkylating agents, and six had received etoposide. The median interval from HSCT to the onset of osteosarcoma was 6.5 years (range 2.5-15.3), which confirms that children undergoing HSCT should be followed up for many years. In conclusion, osteosarcoma must be included in the differential diagnosis among solid tumors that may develop following HSCT.

Mesenchymal stromal cells having inactivated RB1 survive following low irradiation and accumulate damaged DNA: Hints for side effects following radiotherapy

Following radiotherapy, bone sarcomas account for a significant percentage of recurring tumors. This risk is further increased in patients with hereditary retinoblastoma that undergo radiotherapy. We analyzed the effect of low and medium dose radiation on mesenchymal stromal cells (MSCs) with inactivated RB1 gene to gain insights on the molecular mechanisms that can induce second malignant neoplasm in cancer survivors. MSC cultures contain subpopulations of mesenchymal stem cells and committed progenitors that can differentiate into mesodermal derivatives: adipocytes, chondrocytes, and osteocytes. These stem cells and committed osteoblast precursors are the cell of origin in osteosarcoma, and RB1 gene mutations have a strong role in its pathogenesis. Following 40 and 2000 mGy X-ray exposure, MSCs with inactivated RB1 do not proliferate and accumulate high levels of unrepaired DNA as detected by persistence of gamma-H2AX foci. In samples with inactivated RB1 the radiation treatment did not increase apoptosis, necrosis or senescence versus untreated cells. Following radiation, CFU analysis showed a discrete number of cells with clonogenic capacity in cultures with silenced RB1. We extended our analysis to the other members of retinoblastoma gene family: RB2/P130 and P107. Also in the MSCs with silenced RB2/P130 and P107 we detected the presence of cells with unrepaired DNA following X-ray irradiation. Cells with unrepaired DNA may represent a reservoir of cells that may undergo neoplastic transformation. Our study suggests that, following radiotherapy, cancer patients with mutations of retinoblastoma genes may be under strict controls to evaluate onset of secondary neoplasms following radiotherapy.

Osteosarcoma: prognosis plateau warrants retinoblastoma pathway targeted therapy

Osteosarcoma (OS) is the most common primary bone cancer in children and adolescents, affecting ~560 young patients in the United States annually. The term OS describes a diverse array of subtypes with varying prognoses, but the majority of tumors are high grade and aggressive. Perhaps because the true etiology of these aggressive tumors remains unknown, advances in OS treatment have reached a discouraging plateau, with only incremental improvements over the past 40 years. Thus, research surrounding the pathogenesis of OS is essential, as it promises to unveil novel therapeutic targets that can attack tumor cells with greater specificity and lower toxicity. Among the candidate molecular targets in OS, the retinoblastoma (RB) pathway demonstrates the highest frequency of inactivation and thus represents a particularly promising avenue for molecular targeted therapy. This review examines the present thinking and practices in OS treatment and specifically highlights the relevance of the RB pathway in osteosarcomagenesis. Through further investigation into RB pathway-related novel therapeutic targets, we believe that a near-term breakthrough in improved OS prognosis is possible.

Second primary osteosarcomas in patients with retinoblastoma

OBJECTIVE

Second primary malignancies have become the leading cause of death in retinoblastoma survivors. Although osteosarcoma is the most common second malignancy, little is known about its clinical and therapeutic features.

METHODS

We retrospectively reviewed a database of patients with retinoblastoma and osteosarcoma occurring as a second malignancy between 1964 and 2010 at the National Cancer Center Hospital of Japan.

RESULTS

Among 857 patients with retinoblastoma registered in the database, 10 (1.1%) developed osteosarcoma as a second malignancy. The median age at the onset of retinoblastoma was 3 months, being bilateral in nine patients and unilateral in one. Systemic chemoreduction was performed in three patients and intra-arterial chemotherapy in six; all patients received external beam radiotherapy. The median age at the onset of second primary osteosarcoma was 11.2 years; four were radiation-related and six were located in an extremity. Among five patients treated at our institute, four patients with tumors on an extremity were treated by wide resection with neoadjuvant and adjuvant chemotherapy. Three of these four patients (75%) were good responders to high-dose methotrexate-based multi-agent chemotherapy and survived with no evidence of disease (median follow-up period, 17.3 years). One patient whose temporal bone was affected underwent radiotherapy with chemotherapy but died after local recurrence.

CONCLUSIONS

The clinical outcomes of second primary osteosarcoma in an extremity occurring in retinoblastoma survivors may be more favorable than those of conventional osteosarcoma. Early diagnosis of radiation-related osteosarcoma arising in the craniofacial region should be made at a stage where complete resection is possible.

Radiation-Induced Sarcoma: A 15-Year Experience in a Single Large Tertiary Referral Center

Purpose

The purpose of this study is to report on the incidence and the experience in management of radiation-induced sarcoma (RIS) at a large single center in Korea for 15 years.

Materials and Methods

We retrospectively reviewed the sarcoma registry of a large institution from January 2000 to April 2014.

Results

Out of the 3,674 patients listed in the registry, 33 patients (0.9%) diagnosed with RIS were identified. The median latency of RIS was 12.1 years. The number of cases of RIS increased from four cases in the years 2000-2003 to 14 cases in the years 2012-2014. The most common histology was osteosarcoma (36.4%). The median follow-up period was 23.1 months, the median overall survival (OS) of all patients was 2.9 years, and their 5-year survival rate was 44.7%. Univariate and multivariate analyses showed association of the age at diagnosis (p=0.01) and the treatment aim (p=0.001) with the OS. The median OS and the 5-year survival rate of patients treated with curative surgery (n=19) were 9.6 years and 65%, respectively, and of the conservatively treated patients, 0.7 years and 0% (n=14). Re-irradiation was delivered to nine patients, and radiation toxicity was observed in five patients.

Conclusion

In this study, RIS accounted for 0.9% of the cases of sarcoma, with increasing incidence. Despite the association of curative resection with increased survival, it could be applied to only 58% of the patients. Considering the limited treatment options for RIS, conduct of a genetic study to identify the underlying mechanism of RIS is needed.

Comparative Aspects of Osteosarcoma Pathogenesis in Humans and Dogs

Osteosarcoma (OS) is a primary and aggressive bone sarcoma affecting the skeleton of two principal species, human beings and canines. The biologic behavior of OS is conserved between people and dogs, and evidence suggests that fundamental discoveries in OS biology can be facilitated through detailed and comparative studies. In particular, the relative genetic homogeneity associated with specific dog breeds can provide opportunities to facilitate the discovery of key genetic drivers involved in OS pathogenesis, which, to-date, remain elusive. In this review, known causative factors that predispose to the development OS in human beings and dogs are summarized in detail. Based upon the commonalities shared in OS pathogenesis, it is likely that foundational discoveries in one species will be translationally relevant to the other and emphasizes the unique opportunities that might be gained through comparative scientific approaches.

Tumor Induction in Mice After Localized Single- or Fractionated-Dose Irradiation: Differences in Tumor Histotype and Genetic Susceptibility Based on Dose Scheduling

PURPOSE

To investigate differences in tumor histotype, incidence, latency, and strain susceptibility in mice exposed to single-dose or clinically relevant, fractioned-dose γ-ray radiation.

METHODS AND MATERIALS

C3Hf/Kam and C57BL/6J mice were locally irradiated to the right hindlimb with either single large doses between 10 and 70 Gy or fractionated doses totaling 40 to 80 Gy delivered at 2-Gy/d fractions, 5 d/wk, for 4 to 8 weeks. The mice were closely evaluated for tumor development in the irradiated field for 800 days after irradiation, and all tumors were characterized histologically.

RESULTS

A total of 210 tumors were induced within the radiation field in 788 mice. An overall decrease in tumor incidence was observed after fractionated irradiation (16.4%) in comparison with single-dose irradiation (36.1%). Sarcomas were the predominant postirradiation tumor observed (n=201), with carcinomas occurring less frequently (n=9). The proportion of mice developing tumors increased significantly with total dose for both single-dose and fractionated schedules, and latencies were significantly decreased in mice exposed to larger total doses. C3Hf/Kam mice were more susceptible to tumor induction than C57BL/6J mice after single-dose irradiation; however, significant differences in tumor susceptibilities after fractionated radiation were not observed. For both strains of mice, osteosarcomas and hemangiosarcomas were significantly more common after fractionated irradiation, whereas fibrosarcomas and malignant fibrous histiocytomas were significantly more common after single-dose irradiation.

CONCLUSIONS

This study investigated the tumorigenic effect of acute large doses in comparison with fractionated radiation in which both the dose and delivery schedule were similar to those used in clinical radiation therapy. Differences in tumor histotype after single-dose or fractionated radiation exposures provide novel in vivo evidence for differences in tumor susceptibility among stromal cell populations.

Alteration of WWOX in human cancer: a clinical view

WWOX gene is located in FRA16D, the highly affected chromosomal fragile site. Its tumor suppressor activity has been proposed on a basis of numerous genomic alterations reported in chromosome 16q23.3-24.1 locus. WWOX is affected in many cancers, showing as high as 80% loss of heterozygosity in breast tumors. Unlike most tumor suppressors impairing of both alleles of WWOX is very rare. Despite cellular and animal models information on a WWOX role in cancer tissue is limited and sometimes confusing. This review summarizes information on WWOX in human tumors.

Second cancer risk in childhood cancer survivors treated with intensity-modulated radiation therapy (IMRT)

BACKGROUND

Treatment with radiotherapy (RT) is associated with an increased risk of second malignant neoplasms (SMNs) in childhood cancer survivors; it is unclear how treatment with intensity-modulated radiation therapy (IMRT) impacts this risk. We provide the first report of SMN risk in a cohort of childhood cancer survivors treated with IMRT.

PROCEDURE

Retrospective review of patients ≤21 years of age treated with IMRT at Memorial Sloan Kettering Cancer Center between December 1998 and February 2009. Eligible patients survived at least 5 years from IMRT initiation. The risk of SMN was assessed via standardized incidence ratios (SIRs) and excess absolute risk (EAR). The cumulative incidence was estimated using methods for competing risks.

RESULTS

Among 242 patients, six developed SMNs: four developed second solid cancers (all within the radiation field), and two developed myelodysplastic syndrome. Median time from IMRT initiation to a second solid cancer was 7.2 years (range, 6.8-9.5), with a 10-year cumulative incidence of 3.3% (95% confidence interval [CI], 1.0-7.8%), SIR of 11.4 (95% CI, 3.1-29.2) and EAR of 1.8 per 1,000 person-years (95% CI, -0.1 to 3.8).

CONCLUSIONS

Longer follow-up is required to determine how the risk of SMN after IMRT compares to other modalities of radiation treatment, such as proton therapy. This study provides a preliminary report, which will serve as a baseline for future longitudinal analyses of SMN risk after IMRT. Pediatr Blood Cancer 2015;62:311-316. © 2014 Wiley Periodicals, Inc.

Late effects of childhood cancer and its treatment

Treatment for childhood cancer with chemotherapy, radiation and/or hematopoietic cell transplant can result in adverse sequelae that may not become evident for many years. A clear understanding of the association between therapeutic exposures and specific long-term complications, and an understanding of the magnitude of the burden of morbidity borne by childhood cancer survivors, has led to the development of guidelines to support lifelong risk-based follow up for this population. It is important to develop interventions to reduce the impact of treatment-related late effects on morbidity and mortality and to continue research regarding the etiopathogenesis of therapy-related cancers and other late effects.

Assessment of uncertainties in radiation-induced cancer risk predictions at clinically relevant doses

PURPOSE

Theoretical dose-response models offer the possibility to assess second cancer induction risks after external beam therapy. The parameters used in these models are determined with limited data from epidemiological studies. Risk estimations are thus associated with considerable uncertainties. This study aims at illustrating uncertainties when predicting the risk for organ-specific second cancers in the primary radiation field illustrated by choosing selected treatment plans for brain cancer patients.

METHODS

A widely used risk model was considered in this study. The uncertainties of the model parameters were estimated with reported data of second cancer incidences for various organs. Standard error propagation was then subsequently applied to assess the uncertainty in the risk model. Next, second cancer risks of five pediatric patients treated for cancer in the head and neck regions were calculated. For each case, treatment plans for proton and photon therapy were designed to estimate the uncertainties (a) in the lifetime attributable risk (LAR) for a given treatment modality and (b) when comparing risks of two different treatment modalities.

RESULTS

Uncertainties in excess of 100% of the risk were found for almost all organs considered. When applied to treatment plans, the calculated LAR values have uncertainties of the same magnitude. A comparison between cancer risks of different treatment modalities, however, does allow statistically significant conclusions. In the studied cases, the patient averaged LAR ratio of proton and photon treatments was 0.35, 0.56, and 0.59 for brain carcinoma, brain sarcoma, and bone sarcoma, respectively. Their corresponding uncertainties were estimated to be potentially below 5%, depending on uncertainties in dosimetry.

CONCLUSIONS

The uncertainty in the dose-response curve in cancer risk models makes it currently impractical to predict the risk for an individual external beam treatment. On the other hand, the ratio of absolute risks between two modalities is less sensitive to the uncertainties in the risk model and can provide statistically significant estimates.

Translational biology of osteosarcoma

For the past 30 years, improvements in the survival of patients with osteosarcoma have been mostly incremental. Despite evidence of genomic instability and a high frequency of chromothripsis and kataegis, osteosarcomas carry few recurrent targetable mutations, and trials of targeted agents have been generally disappointing. Bone has a highly specialized immune environment and many immune signalling pathways are important in bone homeostasis. The success of the innate immune stimulant mifamurtide in the adjuvant treatment of non-metastatic osteosarcoma suggests that newer immune-based treatments, such as immune checkpoint inhibitors, may substantially improve disease outcome.

Reducing radiation exposure in early-onset scoliosis surgery patients: novel use of ultrasonography to measure lengthening in magnetically-controlled growing rods

BACKGROUND CONTEXT

Magnetically-controlled growing rod (MCGR) technology has been reported for the treatment of early-onset scoliosis (EOS). Such technology allows for regular and frequent outpatient rod distractions without the need for additional surgery. However, pre- and postdistraction spine radiographs are required to verify the amount of lengthening. This increased exposure to ionizing radiation in developing children significantly increases their risk profile for radiation-induced cancer and noncancerous morbidity.

PURPOSE

This study addressed the first and novel application and reliability of the use of ultrasonography, that has no ionizing radiation exposure, as an alternative to plain radiographs in the visualizing and confirming of rod distractions.

STUDY DESIGN

A prospective study.

PATIENT SAMPLE

Six EOS patients who underwent surgical treatment with MCGRs were prospectively recruited.

OUTCOME MEASURES

Imaging measurements based on ultrasound and plain radiographs.

METHODS

All patients were imaged via ultrasound, ease of rod identification was established, and the reliability and reproducibility of optimal reference point selection assessed blindly by three individuals. The clinical algorithm, using ultrasound, was subsequently implemented. Plain radiographs served as controls.

RESULTS

Assessment of the rod's neck distance on ultrasound demonstrated a high degree of interrater reliability (a=0.99; p<.001). Intrarater reliability remained high on repeat measurements at different time intervals (a=1.00; p<.001). Satisfactory interrater reliability was noted when measuring the rod's neck (a=0.73; p=.010) and high reliability was noted in assessing the housing of the rod (a=0.85; p=.01) on plain radiographs. Under blinded conditions, 2 mm rod distraction measured on radiographs corresponded to 1.7 mm distraction on the ultrasound (standard deviation: 0.24 mm; p<.001). Subsequently, the clinical algorithm using ultrasound, instead of radiographs, has been successfully implemented.

CONCLUSIONS

This is the first study to report the use of a novel technique using noninvasive, nonionizing ultrasound to reliably document rod distractions in EOS patients. A high level of inter- and intrarater reliabilities were noted. More importantly, the use of ultrasonography may result in fewer whole spine radiographs from being taken in patients who have had MCGRs implanted for EOS; thereby decreasing their exposure to ionizing radiation and the potential risk of future radiation-induced diseases.

Risk of subsequent malignant neoplasms in long-term hereditary retinoblastoma survivors after chemotherapy and radiotherapy

PURPOSE

Hereditary retinoblastoma (Rb) survivors have increased risk of subsequent malignant neoplasms (SMNs). Previous studies reported elevated radiotherapy (RT) -related SMN risks, but less is known about chemotherapy-related risks.

PATIENTS AND METHODS

In a long-term follow-up study of 906 5-year hereditary Rb survivors diagnosed from 1914 to 1996 and observed through 2009, treatment-related SMN risks were quantified using cumulative incidence analyses and multivariable Cox proportional hazards regression models with age as the underlying time scale.

RESULTS

Nearly 90% of Rb survivors were treated with RT, and almost 40% received alkylating agent (AA) -containing chemotherapy (predominantly triethylenemelamine). Median follow-up time to first SMN diagnosis was 26.3 years. Overall SMN risk was not significantly elevated among survivors receiving AA plus RT versus RT without chemotherapy (hazard ratio [HR], 1.27; 95% CI, 0.99 to 1.63). AA-related risks were significantly increased for subsequent bone tumors (HR, 1.60; 95% CI, 1.03 to 2.49) and leiomyosarcoma (HR, 2.67; 95% CI, 1.22 to 5.85) but not for melanoma (HR, 0.74; 95% CI, 0.36 to 1.55) or epithelial tumors (HR, 0.89; 95% CI, 0.48 to 1.64). Leiomyosarcoma risk was significantly increased for survivors who received AAs at age < 1 (HR, 5.17; 95% CI, 1.76 to 15.17) but not for those receiving AAs at age ≥ 1 year (HR, 1.75; 95% CI, 0.68 to 4.51). Development of leiomyosarcoma was significantly more common after AA plus RT versus RT (5.8% v 1.6% at age 40 years; P = .01).

CONCLUSION

This comprehensive quantification of SMN risk after chemotherapy and RT among hereditary Rb survivors also demonstrates an AA-related contribution to risk. Although triethylenemelamine is no longer prescribed, our findings warrant further follow-up to investigate potential SMN risks associated with current chemotherapies used for Rb.

Methodological extensions of meta-analysis with excess relative risk estimates: application to risk of second malignant neoplasms among childhood cancer survivors treated with radiotherapy

Although radiotherapy is recognized as an established risk factor for second malignant neoplasms (SMNs), the dose response of SMNs following radiotherapy has not been well characterized. In our previous meta-analysis of the risks of SMNs occurring among children who have received radiotherapy, the small number of eligible studies precluded a detailed evaluation. Therefore, to increase the number of eligible studies, we developed a method of calculating excess relative risk (ERR) per Gy estimates from studies for which the relative risk estimates for several dose categories were available. Comparing the calculated ERR with that described in several original papers validated the proposed method. This enabled us to increase the number of studies, which we used to conduct a meta-analysis. The overall ERR per Gy estimate of radiotherapy over 26 relevant studies was 0.60 (95%CI: 0.30-1.20), which is smaller than the corresponding estimate for atomic bomb survivors exposed to radiation as young children (1.7; 95% CI: 1.1-2.5). A significant decrease in ERR per Gy with increase in age at exposure (0.85 times per annual increase) was observed in the meta-regression. Heterogeneity was suggested by Cochran's Q statistic (P < 0.001), which may be partly accounted for by age at exposure.

Metachronous myxofibrosarcoma and osteosarcoma: case report and review of the literature

The occurrence of multiple primary sarcomas in one individual is very uncommon and the development of osteosarcoma as a second tumor following a soft tissue sarcoma is extremely rare. We report a case of a 62-year-old man who developed 2 histologically distinct sarcomas: a soft tissue myxofibrosarcoma and vertebral osteosarcoma. This unusual case highlights the critical role of careful histopathological evaluation in distinguishing synchronous or metachronous neoplasia from metastatic tumor. To the best of the authors' knowledge, this is the first reported case of metachronous soft tissue myxofibrosarcoma and osteosarcoma.

Radiation-induced osteosarcoma of the hand: case report

Radiation-associated sarcomas represent less than 5% of all sarcomas and can arise from previously irradiated bone or soft tissue. We report a case of radiation-associated osteosarcoma that developed in the hand of a patient who had previously been treated for synovial sarcoma. Despite aggressive, multimodality treatment, the disease progressed rapidly. This case highlights the need for patients and treating physicians to be aware of this potential complication of radiotherapy to the hand.

Risk of second bone sarcoma following childhood cancer: role of radiation therapy treatment

Bone sarcoma as a second malignancy is rare but highly fatal. The present knowledge about radiation-absorbed organ dose-response is insufficient to predict the risks induced by radiation therapy techniques. The objective of the present study was to assess the treatment-induced risk for bone sarcoma following a childhood cancer and particularly the related risk of radiotherapy. Therefore, a retrospective cohort of 4,171 survivors of a solid childhood cancer treated between 1942 and 1986 in France and Britain has been followed prospectively. We collected detailed information on treatments received during childhood cancer. Additionally, an innovative methodology has been developed to evaluate the dose-response relationship between bone sarcoma and radiation dose throughout this cohort. The median follow-up was 26 years, and 39 patients had developed bone sarcoma. It was found that the overall incidence was 45-fold higher [standardized incidence ratio 44.8, 95 % confidence interval (CI) 31.0-59.8] than expected from the general population, and the absolute excess risk was 35.1 per 100,000 person-years (95 % CI 24.0-47.1). The risk of bone sarcoma increased slowly up to a cumulative radiation organ absorbed dose of 15 Gy [hazard ratio (HR) = 8.2, 95 % CI 1.6-42.9] and then strongly increased for higher radiation doses (HR for 30 Gy or more 117.9, 95 % CI 36.5-380.6), compared with patients not treated with radiotherapy. A linear model with an excess relative risk per Gy of 1.77 (95 % CI 0.6213-5.935) provided a close fit to the data. These findings have important therapeutic implications: Lowering the radiation dose to the bones should reduce the incidence of secondary bone sarcomas. Other therapeutic solutions should be preferred to radiotherapy in bone sarcoma-sensitive areas.

Osteosarcoma

Osteosarcoma is a malignant tumor that primarily affects the long bones but can also involve other bones in the body.  It has a bimodal distribution with peaks in the second decade of life and late adulthood.  This chapter will highlight the clinical presentation, diagnosis, and treatment of osteosarcoma.