Neoadjuvant chemotherapy and local radiotherapy for high-grade osteosarcoma of the extremities

Exploring the Role of External Beam Radiation Therapy in Osteosarcoma Treatment: Impact of Diagnostic Imaging Delays and Innovative Techniques

Osteosarcomas are a type of bone cancer that typically affect young adults, often in the bones of the arms and legs. To treat osteosarcoma, doctors typically use a combination of chemotherapy, radiotherapy, and surgery, with External Beam Radiation Therapy (EBRT) being the most commonly used form of radiotherapy. EBRT involves directing high-energy photons, X-rays, gamma rays, protons, and electrons at the tumor to induce cancer cell death. Additionally, healthcare providers use imaging techniques to monitor treatment success. This literature review aims to explore the relationship between osteosarcomas and EBRT, investigate the impact of the delayed diagnosis on survival rates, and examine the effectiveness of innovative uses of EBRT for treating osteosarcomas in unusual locations using comprehensive diagnostic techniques. To achieve these objectives, the review examines case studies and literary analyses and categorizes them based on the delay between symptom onset and diagnosis. The null hypothesis is that the presence or absence of a delay in diagnosis does not significantly impact outcomes for the "Delay" category. A lack of delay results in a more favorable outcome in the "Lack of Delay" category. However, the data and statistical results suggest that additional follow-up care in patients with rare or commonly recurring cancers could benefit outcomes. It is important to note that due to the rarity of osteosarcoma with EBRT, the small sample size in the studies warrants further investigation. Interestingly, many patients presented with head and neck tumors despite the most common location of osteosarcoma being in the long bones.

Development of nomogram and discussion of radiotherapy effect for osteosarcoma survival

This study aimed to develop a predictive system for prognostic evaluation of osteosarcoma patients. We obtained osteosarcoma sample data from 1998 to 2016 using SEER*Stat software version 8.3.8, and established a multivariable Cox regression model using R-4.0.3 software. Data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The diagnosis of the model was completed through influential cases, proportionality, and multicollinearity. The predictive ability of the model was tested using area under the curve (AUC), calibration curves, and Brier scores. Finally, the bootstrap method was used to internally verify the model. In total, data from 3566 patients with osteosarcoma were included in this study. The multivariate Cox regression model was used to determine the independent prognostic variables. A nomogram and Kaplan-Meier survival curve were established. The AUC and Brier scores indicated that the model had a good predictive calibration. In addition, we found that the radiotherapy appears to be a risk factor of patients with osteosarcoma and made a discussion. We developed a prognostic evaluation system for patients with osteosarcoma for 1-, 3-, and 5-year overall survival with good predictive ability using sample data extracted from the SEER database. This has important clinical significance for the early identification and treatment of high-risk groups of osteosarcoma patients.

Controversies and Challenges in the Management of Osteosarcoma-an Indian Perspective

Osteosarcoma (OGS) is the most common primary bone tumor in children and adolescents which requires a multidisciplinary approach to management. Although chemotherapy and surgery can cure more than half of localized OGS cases, the unique challenges faced by resource-limited countries like India make this outcome difficult to achieve. Various questions in the management of OGS including role of high-dose methotrexate (HDMTX) in neoadjuvant setting, triplet vs doublet chemotherapy, intensification of chemotherapy based on response in setting of doublet, and indigenous prosthesis in setting of limb salvage need to be defined. Similarly, in the metastatic and recurrent setting, questions regarding intent of treatment, indications of chemotherapy, timing of surgery, and role of targeted therapies need clarification. Lack of randomized trials from India makes definite conclusions difficult, but an attempt can be made to define the best approach in the Indian scenario from available evidence. Hence, a critical review of literature from India and the West was done to define possible management approaches and highlight the lacuna for future research.

Current and future targeted alpha particle therapies for osteosarcoma: Radium-223, actinium-225, and thorium-227

Osteosarcoma is a high-grade sarcoma characterized by osteoid formation, nearly universal expression of IGF1R and with a subset expressing HER-2. These qualities provide opportunities for the use of the alpha particle-emitting isotopes to provide targeted radiation therapy via alpha particles precisely to bone-forming tumors in addition to IFG1R or Her-2 expressing metastases. This review will detail experience using the alpha emitter radium-223 (²²³Ra, tradename Xofigo), that targets bone formation, in osteosarcoma, specifically related to patient selection, use of gemcitabine for radio-sensitization, and using denosumab to increasing the osteoblastic phenotype of these cancers. A case of an inoperable left upper lobe vertebral-paraspinal-mediastinal osteoblastic lesion treated successfully with ²²³Ra combined with gemcitabine is described. Because not all areas of osteosarcoma lesions are osteoblastic, but nearly all osteosarcoma cells overexpress IGF1R, and some subsets expressing Her-2, the anti-IGF1R antibody FPI-1434 linked to actinium-225 (²²⁵Ac) or the Her-2 antibody linked to thorium-227 (²²⁷Th) may become other means to provide targeted alpha particle therapy against osteosarcoma (NCT03746431 and NCT04147819).

Identification of potential key genes and functional role of CENPF in osteosarcoma using bioinformatics and experimental analysis

Osteosarcoma, which arises from bone tissue, is considered to be one of the most common types of cancer in children and teenagers. As the etiology of osteosarcoma has not been fully elucidated, the overall prognosis for patients is generally poor. In recent years, the development of bioinformatical technology has allowed researchers to identify numerous molecular biological characteristics associated with the prognosis of osteosarcoma using online databases. In the present study, Gene Expression Omnibus (GEO) database was used and three microarray datasets were obtained. The GEO2R web tool was utilized and differentially expressed genes (DEGs) in osteosarcoma tissue were identified. Venn analysis was performed to determine the intersection of the DEG profiles. DEGs were analyzed by Gene Ontology function and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. Protein-protein interactions (PPIs) between these DEGs were analyzed using the Search Tool for the Retrieval of Interacting Genes database, and the PPI network was then visualized using Cytoscape software. The top ten genes were identified based on measurement of degree, density of maximum neighborhood component, maximal clique centrality and mononuclear cell counts in the PPI network, and five overlapping genes [origin recognition complex subunit 6 (ORC6), IGF-binding protein 5 (IGFBP5), minichromosome maintenance 10 replication initiation factor (MCM10), MET proto-oncogene, receptor tyrosine kinase (MET) and centromere protein F (CENPF)] were identified. Additionally, three module networks were analyzed by Molecular Complex Detection (MCODE), and six key genes [ORC6, MCM10, DEP domain containing 1 (DEPDC1), CENPF, TIMELESS interacting protein (TIPIN) and shugoshin 1 (SGOL1)] were screened. Combined with the results from Cytoscape and MCODE, eight hub genes (ORC6, MCM10, DEPDC1, CENPF, TIPIN, SGOL1, MET and IGFBP5) were obtained. Furthermore, Kaplan-Meier plotter survival analysis was used to evaluate the prognostic value of these eight hub genes in patients with osteosarcoma. Oncomine and GEPIA databases were applied to further confirm the expression levels of hub genes in tissue. Finally, the functional roles of the core gene CENPF were investigated using Cell Counting Kit-8, wound healing and Transwell assays, which indicated that CENPF knockdown inhibited the proliferation, migration and invasion of osteosarcoma cells. These results provided potential prognostic markers, as well as a basis for further investigation of the mechanism underlying osteosarcoma.

Carbon-ion radiotherapy in osteosarcoma of the mandible: a case report

Carbon-ion radiotherapy (CIRT) is on the rise as a treatment choice for malignant tumor. Compared to conventional radiotherapy, particle beams have different physical and biological properties. Particle beam provides a low entry dose, deposits most of the energy at the endpoint of the flight path, and forms an asymptotic dose peak (the "Bragg peak"). Compared to protons, carbon with its larger mass decreases beam scattering, resulting in a sharper dose distribution border. We report a 50-year-old male who underwent CIRT without surgical resection on osteosarcoma of the mandible. After CIRT, the patient's pain was gone, and the malignant mass remained stable with accompanying necrosis. Nine months later, however, magnetic resonance imaging demonstrated progression of the left mandibular osteosarcoma with pulmonary metastases. After multidisciplinary discussion, concurrent chemoradiotherapy was conducted. While necrotic bone segments came out of the mandible during subsequent periodic outpatient visits, the tumor itself was stable. Thirty months after his first visit and diagnosis, the patient is waiting for chemotherapy. Although CIRT is superior in treating radioresistant hypoxic disease, CIRT is in its infancy, so care must be taken for its indications and complications.

The effect of preoperative radiotherapy on local control and prognosis in high-grade non-metastatic intramedullary osteosarcoma of the extremities

INTRODUCTION

This study aimed to analyse the effect of preoperative radiotherapy on survival, recurrence and necrosis rates in osteosarcoma patients treated with neoadjuvant chemotherapy and limb-salvage surgery.

MATERIALS AND METHODS

Osteosarcoma patients who referred to our clinic from 1998 to 2015 were investigated retrospectively. 141 patients with non-metastatic osteosarcoma of the limb who received neoadjuvant chemotherapy and underwent limb-sparing surgery with or without preoperative radiotherapy were included in the study. 73 patients had neoadjuvant chemotherapy only (CT group), while 68 patients had additional preoperative radiotherapy (CT + RT group). 5-year survival, disease-free survival, limb survival, local recurrence, metastasis, complication and necrosis rates were compared between the two groups.

RESULTS

Overall 5-year survival, 5-year disease-free survival, 5-year limb survival rates were 68.5, 64.3, 65.7 for CT group and 72.1, 67.6, 64.7 for CT + RT group, respectively. Preoperative radiotherapy gave similar survival and disease-free survival rates. Limb survival, recurrence and metastasis rates were similar between the groups. The necrosis rate of the lesions was significantly higher in the CT + RT group compared to the CT group.

CONCLUSION

Preoperative radiotherapy can provide a higher necrosis rate and may allow the resection of unresectable lesions in the treatment of osteosarcoma. CT + RT provided similar 5-year survival despite the larger tumour size compared to CT group. Due to the higher wound complication rate (8.2% in CT, 23.5% in CT + RT group, p = 0.01), CT + RT should be restricted to the lesions with large size or close proximity to neurovascular structures.

LEVEL OF EVIDENCE

Level III; Therapeutic, Retrospective comparative study.

Osteosarcoma

Osteosarcoma is a rare tumor that requires complex multidisciplinary management. This paper reviews the general management and standard radiotherapy guidelines for osteosarcoma in both North America and Europe in a joined effort between the Children's Oncology Group and International Society of Pediatric Oncology. Standard treatment involves multiagent induction chemotherapy followed by surgical resection for local tumor control and consolidation local control to metastatic sites. Radiotherapy is reserved for cases with a marginal or incomplete resection or for definitive treatment in the case of unresectable disease. We present supporting data for the role of chemotherapy, surgery, and radiation therapy.

Surgical resection of the primary lesion for osteosarcoma patients with metastasis at initial diagnosis

BACKGROUND

Approximately 10-20% of osteosarcoma patients present with metastasis on diagnosis. Completely resecting the lesion is associated with better prognosis. However, evidence regarding optimal surgical strategies for patients with unresectable metastasis is limited.

METHODS

This retrospective analysis was based on the Japanese Nationwide Bone and Soft Tissue Tumor registry. In total, 335 patients diagnosed with osteosarcoma with metastasis were included. Factors affecting overall survival were identified using multivariate analysis. Kaplan-Meier method was used to compare the overall survival by the status of surgical intervention. Two hundred and four patients who did not undergo surgery for metastasis were divided into two groups, depending on whether they underwent surgery for the primary lesion. The background differences between these two groups were adjusted with propensity score matching, with 43 patients per group. The overall survival was calculated using the Kaplan-Meier method and compared with a log-rank test.

RESULTS

Factors positively impacting overall survival were age <40, female sex, extremity origin, surgery for the primary lesions, surgery for metastasis and radiotherapy without surgery. For patients with unresectable metastasis, after propensity score matching, the survival rate was higher in the group that underwent primary lesion surgery than the group without surgery. Their median survival was 19 (95% confidence interval: 11.7-26.3) and 11 months (95% confidence interval: 4.5-17.5) (P = 0.02), respectively.

CONCLUSIONS

Surgical resection of the primary osteosarcoma lesion did not worsen prognosis, even in patients with unresectable metastasis. Further study is needed to identify which patient group will benefit from primary lesion resection.

Osteosarcoma: a review of current and future therapeutic approaches

Osteosarcoma (OS) is the most common primary bone malignancy that affects children and young adults. OS is characterized by a high degree of malignancy, strong invasiveness, rapid disease progression, and extremely high mortality rate; it is considered as a serious threat to the human health globally. The incidence of OS is common in the metaphysis of long tubular bones, but rare in the spine, pelvis, and sacrum areas; moreover, majority of the OS patients present with only a single lesion. OS has a bimodal distribution pattern, that is, its incidence peaks in the second decade of life and in late adulthood. We examine historical and current literature to present a succinct review of OS. In this review, we have discussed the types, clinical diagnosis, and modern and future treatment methods of OS. The purpose of this article is to inspire new ideas to develop more effective therapeutic options.

Radiotherapy in the Management of Pediatric and Adult Osteosarcomas: A Multi-Institutional Cohort Analysis

Background: Due to the rarity of osteosarcoma and limited indications for radiotherapy (RT), data on RT for this tumor are scarce. This study aimed to investigate the utilization of RT for osteosarcomas in the recent 20 years and to identify factors related to patients’ response to radiation. Methods: We performed a retrospective analysis of patients irradiated for osteosarcoma treatment. We planned to assess differences in the utilization of RT between the periods of 2000–2010 and 2011–2020, identify the risk factors associated with local progression (LP), determine whether RT-related parameters are associated with LP, and calculate patients’ survival. Results: A total of 126 patients with osteosarcoma who received 181 RT treatments were identified. We found a difference in RT techniques between RT performed in the years 2000–2010 and that performed in the years 2011–2020. LP was observed after 37 (20.4%) RT treatments. Intent of RT, distant metastases, and concomitant systemic treatment affected the risk of LP. Five-year overall survival was 33% (95% confidence interval (26%–43%)). Conclusions: RT for osteosarcoma treatment has evolved from simple two-dimensional palliative irradiation into more conformal RT applied for new indications including oligometastatic and oligoprogressive disease. RT may be a valuable treatment modality for selected patients with osteosarcoma.

Radiosensitizing effects of c‑myc gene knockdown‑induced G2/M phase arrest by intrinsic stimuli via the mitochondrial signaling pathway

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents and its long‑term survival rate has stagnated in the past decades. Previous studies have shown that tumors in the G2/M phase are more sensitive to radiotherapy. The proto‑oncogene c‑myc is a transformed member of the myc family and c‑myc‑interacting zinc finger protein‑1 (Miz‑1) is a poly‑Cys2His2 zinc finger (ZF) activator of cell cycle regulator genes, such as the cyclin‑dependent kinase inhibitor p21. C‑myc can repress the expression of p21 by binding to Miz‑1 and abolishing the interaction between Miz‑1 and its co‑activators, which induces G2/M phase arrest. Therefore, the present study investigated the radiosensitizing effects of the c‑myc gene and the sensitizing apoptosis pathway, aiming to identify a more effective combination radiotherapy treatment for osteosarcoma. The present study demonstrated that the c‑myc gene was overexpressed in osteosarcoma cells compared to osteoblasts. Following inhibition of c‑myc gene expression in osteosarcoma cells, tumor proliferation was significantly hindered after inducing G2/M phase arrest via regulating G2/M phase‑associated proteins. Additionally, it was revealed that inhibiting c‑myc gene expression combined with radiotherapy could significantly increase the apoptosis rate of osteosarcoma cells via the mitochondrial signaling pathway. In summary, the present study verified the radiosensitizing effects of c‑myc gene knockdown‑induced G2/M phase arrest, which was achieved by intrinsic stimuli through the mitochondrial signaling pathway.

What is the best clinical approach to recurrent/refractory osteosarcoma?

Introduction: Osteosarcoma is the most common malignant bone tumor. It is currently treated with pre-and postoperative chemotherapy, associated with surgical resection of the tumor.Area covered: Relapses occur in about one in three patients presenting with localized disease, and three in four of those with metastases at diagnosis. Relapsing disease carries a very poor prognosis, with 5-year survival rates ranging between 13% and 40%.Expert opinion: Patients with unilateral lung involvement or solitary lung metastases and a recurrence-free interval (RFI) longer than 24 months have a better prognosis, and could be managed with surgical resection and close observation. Complete surgical resection of all sites of disease remains essential to survival: patients unable to achieve complete remission have a catastrophic overall survival rate. The role of second-line chemotherapy is not at all clear, and no controlled studies are available on this topic. It is worth considering for patients unable to achieve complete surgical remission, and those with multiple metastases and/or a RFI <24 months. Given their dismal prognosis, patients with multiple sites of disease not amenable to complete surgical resection should also be considered for innovative therapeutic approaches.

Alpha-Particle Therapy for Multifocal Osteosarcoma: A Hypothesis

Osteosarcoma (OST) is the most common bone tumor in children and adolescents with a second peak of incidence in elderly adults usually diagnosed as secondary tumors in Paget's disease or irradiated bone. Subjects with metastatic disease or whose disease relapses after the initial therapy have a poor prognosis. Moreover, multifocal OST contains tumor-initiating cells that are resistant to chemotherapy. The use of aggressive therapies in an attempt to eradicate these cells can have long-term negative consequences in these vulnerable patient populations. ²²⁷Th-labeled molecular probes based on ligands to OST-associated receptors such as IGF-1R (insulin-like growth factor receptor 1), HER2 (human epidermal growth factor receptor 2), and PSMA (prostate-specific membrane antigen) are expected to detect and treat osseous and nonosseous sites of multifocal OST. Published reports indicate that ²²⁷Th has limited myelotoxicity, can be stably chelated to its carriers and, as it decays at targeted sites, ²²⁷Th produces ²²³Ra that is subsequently incorporated into the areas of increased osteoblastic activity, that is, osseous metastatic lesions. Linear energy transfer of α particles emitted by ²²⁷Th and its daughter ²²³Ra is within the range of the optimum relative biological effectiveness. The radiotoxicity of α particles is virtually independent of the phase in the cell cycle, oxygenation, and the dose rate. For these reasons, even resistant OST cells remain susceptible to killing by high-energy α particles, which can also kill adjacent quiescent OST cells or cells with low expression of targeted receptors. Systemic side effects are minimized by the limited range of these intense radiations. Quantitative single-photon emission computed tomography of ²²⁷Th and ²²³Ra is feasible. Additionally, the availability of radionuclide pairs, for example, ⁸⁹Zr for positron emission tomography and ²²⁷Th for therapy, establish a strong basis for the theranostic use of ²²⁷Th in the individualized treatment of multifocal OST.

Outcomes for pediatric patients with osteosarcoma treated with palliative radiotherapy

BACKGROUND

Few studies have addressed the efficacy of palliative radiotherapy (RT) for pediatric osteosarcoma (OS), a disease generally considered to be radioresistant. We describe symptom relief, local control, and toxicity associated with palliative RT among children with OS.

PROCEDURE

Patients diagnosed with OS at age 18 and under and treated with RT for palliation of symptomatic metastases or local recurrence at the primary site from 1997 to 2017 were included. We retrospectively reviewed details of RT, symptom improvement, local control, survival, and toxicity.

RESULTS

Thirty-two courses of palliative RT were given to 20 patients with symptomatic metastatic and/or locally recurrent primary disease. The median equivalent dose in 2 Gy fractions (EQD2) was 40.0 Gy (range, 20.0-60.4). The median number of fractions per course was 15 (range, 5-39). Symptom improvement occurred in 24 (75%) courses of RT at a median time of 15.5 days (range, 3-43). In nine courses (37.5%), symptoms recurred after a median duration of symptom relief of 140 days (range, 1-882). Higher EQD2 correlated with longer duration of response (r = 0.39, P = 0.0003). Imaging revealed local failure in 3 of 14 courses followed with surveillance imaging studies (21.4%). The median time to progression was 12.9 months (range, 4.4-21.8). The median follow-up time following the first course of palliative RT was 17.5 months (range, 1.74-102.24), and median time to overall survival was 19.4 months. Toxicity was mild, with grade 2 toxicity occurring in one course (3.1%).

CONCLUSIONS

RT is an effective method of symptom palliation for patients with recurrent or metastatic OS, with higher delivered dose correlating with longer symptom relief and with little associated toxicity.

The inhibitory effects of cisplatin-radiation combination treatment on malignant osteosarcoma MG-63 cells and BRCA1-p53 pathways are more efficient than single treatments

The poor prognosis of patients with osteosarcoma remains a persistent problem, in particular for patients with unresectable tumors or metastasis. Therefore, combination of radiotherapy and chemotherapy has been considered for patients with metastasis or recurrence, patients unsuitable for surgery and patients refusing surgery. The present study aimed to investigate the effect of the combined treatment with cisplatin and radiation therapy on the biological characteristics of the osteosarcoma cell line MG-63 and the breast cancer 1 (BRCA1)-associated signaling pathways. Cell proliferation was determined using Cell Counting kit-8 assay, and cell apoptosis and cell cycle were assessed by flow cytometry. Cell migration was examined by Transwell assay. The mRNA and protein expression levels of candidate genes, including BRCA1 and p53, were determined by reverse transcription-quantitative PCR and western blotting, respectively. The results demonstrated that combined treatment with radiation and cisplatin significantly inhibited MG-63 cell proliferation compared with radiation or cisplatin treatment alone. Furthermore, radiation, cisplatin or the combined treatment with radiation and cisplatin increased the apoptosis rate of MG-63 cells, which resulted in G₂ phase arrest, and significantly decreased the migratory capacity of MG-63 cells. In addition, the apoptosis rate of MG-63 cells following combined radiation and cisplatin treatment was higher compared with the cisplatin group, but lower compared with the radiation group. Furthermore, combined treatment with radiation and cisplatin decreased the mRNA and protein expression levels of BRCA1 and p53. Additionally, combined treatment with radiation and cisplatin had a more potent inhibitory effect on p53 expression than on BRCA1 expression. In addition, combination of radiation and cisplatin had a higher inhibitory effect on Bax protein level and a higher inductive effect on Bcl-2 protein level compared with treatments with radiation and cisplatin alone. The results demonstrated that combined treatment of radiation and cisplatin exhibited superior therapeutic effects on osteosarcoma MG-63 cells compared with radiation or cisplatin treatment alone, which may be mediated by the BRCA1-p53 signaling pathway.

Risk and clinicopathological features of osteosarcoma metastasis to the lung: A population-based study

Background

Osteosarcoma is the most common primary sarcoma of the bone. Lung osteosarcoma metastases at diagnosis have a significantly poor prognosis, even when surgery plus chemotherapy are performed. Our goal was to analyze clinical and sarcoma characteristics that could help identify factors related to an increased rate of lung metastasis and to identify different modes of treatment and its correlation with survival.

Materials and Methods

The Surveillance, Epidemiology, and End Results (SEER) database was used to identify all osteosarcoma patients diagnosed from 2010 to 2015. Patient characteristics such as age, sex, ethnicity, marital status, tumor location, histologic grade, surgery, chemotherapy, radiation therapy, SEER cause-specific death classification, survival, and lung metastasis were collected. These factors were analyzed using Univariate and multivariate regression models in survival analyses.

Results

A total of 1057 osteosarcoma patients diagnosed from 2010 to 2015 were included, of which 176 were patients with lung metastasis. Substantial disparities in the rate of lung metastasis existed when osteosarcoma patients were stratified according to tumor location (P = 0.0002) and tumor size (P < .001). Using a Multivariate Cox regression model, being older than 30 years (vs. younger than 30, HR = 2.171, 95% CI = 1.623–2.905, P < .0001), having a tumor >5–10 cm (vs. <5 cm, HR = 2.046, 95% CI = 1.153–3.632, P = 0.0014) and >10 cm (vs. <5 cm, HR = 3.610, 95% CI = 2.066–6.310, P < .0001) were related to an increased HR for all-cause death. The HR decreased in patients with surgery (vs. no surgery, HR = 0.189, 95% CI = 0.138–0.260, P < 0.0001) and osteosarcoma. As for osteosarcoma patients with lung metastases, Multivariate Cox regressions revealed that an increased HR was associated with being older than 30 years (vs. younger than 30 years, HR = 2.142, 95% CI = 1.273–3.605, P = .0041) and married (vs. no marriage, HR = 2.418, 95% CI = 1.400–4.176, P= .0015), while a decreased HR was related to having had surgery (vs. no surgery, HR = 0.282, 95% CI = 0.171–0.464, P < .0001) and chemotherapy (vs. no chemotherapy, HR = 0.107, 95% CI = 0.050–0.229, P < .0001).

Conclusions

Advanced age (older than 30 years) and large tumors were related to a higher risk of lung metastases in osteosarcoma patients. Therefore, patients who were diagnosed at advanced age or had large tumors should receive comprehensive chest CT scans. Surgery and chemotherapy can significantly improve the survival of metastatic patients, while radiotherapy did not improve survival in these patients.

A prospective Phase II study for the efficacy of radiotherapy in combination with zoledronic acid in treating painful bone metastases from gastrointestinal cancers

We investigated the efficacy of combined radiotherapy (RT) and zoledronic acid in treating painful bone metastases from gastrointestinal cancers. Sixty patients were prospectively enrolled between November 2014 and July 2016. The most common primary cancer type was hepatocellular carcinoma (HCC, n = 25), followed by colorectal cancer (n = 6). Patients received external beam RT of 30-54 Gy in 10-17 fractions or 20 Gy in 5 fractions for symptomatic bone metastases. On the first day of RT, patients received 4 mg intravenous zoledronic acid, which was repeated monthly for a total of six cycles. The mean pain score before treatment was 6.7, and it decreased to 2.8 at 1 month and 2.1 at 3 months (P < 0.001).The overall pain response rates at 1 and 3 months were 95% and 96%, respectively. Among the 24 patients who underwent magnetic resonance imaging, 71% were responders, with a complete response in 1 patient and partial in 16 patients. Combined treatment significantly decreased levels of macrophage inflammatory protein-1α and matrix metalloproteinase (MMP)-2 and -3 compared with baseline (all P < 0.05). In HCC patients, IL-6 and MMP-9 levels were significantly lower 1 month after treatment (P < 0.05). The mean quality of life (QOL) score improved from 66 to 56 at 1 month (P < 0.001) and 55 at 3 months (P = 0.016). The median survival was 7 months. In conclusion, RT with zoledronic acid decreased bone pain and improved QOL in patients with painful bone metastases from gastrointestinal cancers. Radiographic findings and serum biomarker measurements were closely correlated with therapeutic responses.

Combination of electroporation delivered metabolic modulators with low-dose chemotherapy in osteosarcoma

BACKGROUND

Osteosarcoma accounts for roughly 60% of all malignant bone tumors in children and young adults. The five-year survival rate for localized tumors after surgery and chemotherapy is approximately 70% whilst it drastically reduces to 15-30% in metastatic cases. Metabolic modulation is known to increase sensitivity of cancers to chemotherapy. A novel treatment strategy in Osteosarcoma is needed to battle this devastating malady.

RESULTS

Electroporation-delivered metabolic modulators were more effective in halting the cell cycle of Osteosarcoma cells and this negatively affects their ability to recover and proliferate, as shown in colony formation assays. Electroporation-delivered metabolic modulators increase the sensitivity of Osteosarcoma cells to chemotherapy and this combination reduces their survivability.

CONCLUSION

This novel treatment approach highlights the efficacy of electroporation in the delivery of metabolic modulators in Osteosarcoma cells, and increased sensitivity to chemotherapy allowing for a lower dose to be therapeutic.

METHODS

Metabolic modulations of two Osteosarcoma cell lines were performed with clinically available modulators delivered using electroporation, and its combination with low-dose Cisplatin. The effects of Dicholoroacetic acid, 2-Deoxy-D-glucose and Metformin on cell cycle and recovery of Osteosarcoma cells were assessed. Their sensitivity to chemotherapy was also assessed when treated in combination with electroporation-delivered metabolic modulators.

Zoledronic acid is an effective radiosensitizer in the treatment of osteosarcoma

To overcome radioresistance in the treatment of osteosarcoma, a primary malignant tumor of the bone, radiotherapy is generally combined with radiosensitizers. The purpose of this study was to investigate a third-generation bisphosphonate, zoledronic acid (ZOL), as a radiosensitizer for osteosarcoma. We found that exposure of KHOS/NP osteosarcoma cells to 20 μM ZOL decreased the γ-radiation dose needed to kill 90% of cells. This radiosensitizing effect of ZOL was mediated through decreased mitochondrial membrane potential, increased levels of reactive oxygen species, increased DNA damage (as assessed by counting γ-H2AX foci), decreased abundance of proteins involved in DNA repair pathways (ATR, Rad52, and DNA-PKcs), and decreased phosphorylation of PI3K-Akt and MAPK pathway proteins (Raf1, MEK1/2, ERK1/2, and Akt), as compared to γ-irradiation alone. Cells treated with ZOL plus γ-irradiation showed impaired cell migration and invasion and reduced expression of epithelial-mesenchymal transition markers (vimentin, MMP9, and Slug). In Balb/c nude mice, the mean size of orthotopic osteosarcoma tumors 2 weeks post-inoculation was 195 mm³ following γ-irradiation (8 Gy), while it was 150 mm³ after γ-irradiation plus ZOL treatment (0.1 mg/kg twice weekly for 2 weeks). These results provide a rationale for combining ZOL with radiotherapy to treat osteosarcoma.

Radiotherapy in the Treatment of Primary Osteosarcoma – a Single Center Experience

Purpose

To analyze our experiences concerning radiation treatment in patients with osteosarcoma.

Materials and methods

Since 1981, 40 patients with osteosarcoma have undergone radiotherapy in Heidelberg; 3 of them were immediately lost to follow-up. Twenty patients with metastases were treated palliatively and 17 patients were treated with a curative intent.

Results

Interestingly, 14 of the 17 patients treated with a curative intent were referred to our clinic during the last 8 years, whereas the number of patients referred for palliation decreased. The mean dose applied for palliation was 47 Gy (range, 26 Gy to >70 GyE), for cure was 59 Gy (range, 45 Gy to >70 GyE). Local control until death could be achieved in 15 of the 20 palliatively treated patients, with a mean survival of 7 months after radiation. Five patients experienced local failure with symptom recurrence, and 3 of them had received doses >60 Gy. At last follow-up, 3 of the 17 curatively treated patients had experienced local recurrence. Median follow-up was 32 months (range, 3-144). Estimated 5-year overall survival and local control rates were 38% and 68%, respectively. Local disease-free survival was shorter in patients treated for recurrent, inoperable or incompletely resected tumors and doses below 60 Gy.

Conclusions

With adequate doses, long-term local control is possible even in inoperable or incompletely resected tumors. Improvements of systemic therapy and modern radiation techniques have begun to bring the possibly curative role of radiation treatment back to the fore. However, in disseminated tumors, even doses beyond 60 Gy do not guarantee local control, suggesting an extremely low radiosensitivity of certain kinds of osteosarcoma.

Local Control of Soft Tissue and Bone Sarcomas

Sarcomas of soft tissue and bone are mesenchymal malignancies that can arise in any anatomic location, most commonly the extremity, retroperitoneum, and trunk. Even for lower grade histologic subtypes, local recurrence can cause significant morbidity and even disease-related death. Although surgery remains the cornerstone of local control, perioperative radiation and systemic therapy are often important adjuvants. This review will summarize the current therapeutic approaches for local control of soft tissue and bone sarcomas.

Methotrexate Free Chemotherapy and Limb Salvage Surgery for Paediatric Osteosarcoma in India

BACKGROUND

Osteosarcoma (OS) is the most common primary malignant tumor of bone. The survival of OS patients has steadily improved from <20% in the early 20th century to around 70% with current treatment. There are very few studies in pediatric OS from India analyzing various aspects of the disease. This study focuses on the clinical profile, treatment options, and their complications and survival outcomes in pediatric osteosarcoma (OS) patients.

MATERIALS AND METHODS

This was a retrospective observational study which included pediatric patients <14 years of age, with newly diagnosed OS confirmed by histological diagnosis. Medical records of all patients were reviewed for clinical profile, treatment data, surgical management, and treatment complications. Patients alive at the end of treatment were followed up and overall (OAS) and disease-free survival (DFS) were analyzed.

RESULTS

Sixty-two patients were diagnosed with OS during the study of whom 55 opted for treatment. Cisplatin, adriamycin, and ifosfamide (PAI) was offered as chemotherapy and was completed as planned in the majority of patients. Limb salvage surgery was performed in most patients (87%, n = 40). The local recurrence occurred in 7 patients. The 3 years overall survival for the cohort was 54.6% ± 7.8% and DFS was 43.4% ± 7.9%, with females and those with the localized disease having a significantly better DFS.

CONCLUSIONS

High dose methotrexate free chemotherapy can give good OAS in localized disease and LSS is feasible in most of the pediatric OS patients. However the modest DFS even for localized disease with PAI chemotherapy and extremely poor outcomes in the metastatic OS, demand further research and innovations in systemic therapy to improve outcomes.

Predictive factors of acute skin reactions to carbon ion radiotherapy for the treatment of malignant bone and soft tissue tumors

Background

The skin is considered a critical organ at risk in carbon ion radiotherapy (CIRT) for locally advanced malignant bone and soft tissue tumors (MBSTs). The predictive factors for acute skin reactions after CIRT have not been investigated. The present study aimed to identify these factors and evaluate the correlation between the severity of acute skin reactions and skin dose parameters.

Methods

CIRT with total doses of 64.0–70.4 Gy (relative biological effectiveness [RBE]) was administered to 22 patients with MBSTs. The skin-tumor distance (STD), maximum skin total dose (Dmax), and area of the skin receiving a total dose of X Gy (RBE) were evaluated.

Results

All patients developed acute skin reactions after CIRT, including Grades 1 and 2 dermatitis in 15 (71%) and 6 (29%) patients, respectively. There was a significant difference in the STD between the two groups (P = 0.007), and the cut-off value of STD for predicting Grade 2 acute skin reactions was 11 mm. There was a significant difference in Dmax between the groups (P < 0.001), and the cut-off value of Dmax for predicting Grade 2 acute skin reactions was 52 Gy (RBE). Significant differences between the two groups were observed in terms of the area irradiated with 40 Gy (RBE) (S40), and the cut-off value of S40 for predicting Grade 2 acute skin reactions was 25 cm².

Conclusions

In acute skin reactions after CIRT for MBSTs, STD, Dmax, and S40 were found to be significant predictive factors for acute skin reactions.

Understanding the potentiality of accelerator based-boron neutron capture therapy for osteosarcoma: dosimetry assessment based on the reported clinical experience

BACKGROUND

Osteosarcoma is the most frequent primary malignant bone tumour, and its incidence is higher in children and adolescents, for whom it represents more than 10% of solid cancers. Despite the introduction of adjuvant and neo-adjuvant chemotherapy that markedly increased the success rate in the treatment, aggressive surgery is still needed and a considerable percentage of patients do not survive due to recurrences or early metastases. Boron Neutron Capture Therapy (BNCT), an experimental radiotherapy, was investigated as a treatment that could allow a less aggressive surgery by killing infiltrated tumour cells in the surrounding healthy tissues. BNCT requires an intense neutron beam to ensure irradiation times of the order of 1 h. In Italy, a Radio Frequency Quadrupole (RFQ) proton accelerator has been designed and constructed for BNCT, and a suitable neutron spectrum was tailored by means of Monte Carlo calculations. This paper explores the feasibility of BNCT to treat osteosarcoma using this neutron source based on accelerator.

METHODS

The therapeutic efficacy of BNCT was analysed evaluating the dose distribution obtained in a clinical case of femur osteosarcoma. Mixed field dosimetry was assessed with two different formalisms whose parameters were specifically derived from radiobiological experiments involving in vitro UMR-106 osteosarcoma cell survival assays and boron concentration assessments in an animal model of osteosarcoma. A clinical case of skull osteosarcoma treated with BNCT in Japan was re-evaluated from the point of view of dose calculation and used as a reference for comparison.

RESULTS

The results in the case of femur osteosarcoma show that the RFQ beam would ensure a suitable tumour dose painting in a total irradiation time of less than an hour. Comparing the dosimetry between the analysed case and the treated patient in Japan it turns out that doses obtained in the femur tumour are at least as good as the ones delivered in the skull osteosarcoma. The same is concluded when the comparison is carried out taking into account osteosarcoma irradiations with photon radiation therapy.

CONCLUSIONS

The possibility to apply BNCT to osteosarcoma would allow a multimodal treatment consisting in neo-adjuvant chemotherapy, high-LET selective radiation treatment and a more conservative surgery.

Evaluating Soft-Tissue Lumps and Bumps

Patients presenting with soft-tissue lumps and bumps are commonly encountered by both primary care physicians and orthopaedic surgeons. Though common, the initial evaluation and management of a soft-tissue mass can be challenging for many clinicians due to the considerable overlap in the presentation of benign and malignant tumors. Furthermore, a myriad of conditions, ranging from infection to trauma, can present with a soft-tissue mass. Subsequently, the correct diagnosis is often delayed or missed which may ultimately lead to inappropriate treatment. The propose of this article is to review the fundamental elements of a successful soft-tissue mass work-up and to provide the clinician with a systematic approach to the evaluation, diagnosis and management of the patient with a soft-tissue tumor.

Proton Radiation Therapy for Local Control in a Case of Osteosarcoma of the Neck

A 33-year-old man with symptomatic, unresectable osteosarcoma of the neck experienced disease progression despite treatment with multiple systemic agents. Given the tumor location, adjacent to the spinal cord and encasing the brachial plexus, proton beam therapy was recommended instead of conventional photon radiation therapy. The treatment was delivered in 3 weekly 10 cobalt-gray equivalents fractions, and there was minimal associated toxicity. There has been significant improvement in the patient's presenting symptoms as well as radiologically stable disease at 1 year. A photon intensity-modulated radiation therapy plan was created retrospectively for dosimetric comparison and demonstrated noninferiority, thereby highlighting the need for judicious use of proton therapy in certain cases.

Osteosarcoma of the Mandible: A Site-Specific Study on Survival and Prognostic Factors

Osteosarcoma of head and neck is a rare condition comprising of <1% of all head and neck cancers, retrospective studies show difference in survival of mandibular osteosarcoma to other head and neck sites, necessitating investigation into site-specific survival and recurrence rates.

Malignant Transformation of a High-Grade Osteoblastoma of the Petrous Apex with Subcutaneous Metastasis

We describe the clinical presentation, management, and pathologic findings in a case of osteosarcoma of the petrous apex with an atypical metastasis to the lower abdominal wall. We retrospectively reviewed the record of a 49-year-old man who was diagnosed with a right petrous apex lesion, which biopsy identified as a high-grade osteoblastoma. After two attempts at en bloc resection were not curative, radiation and chemotherapy were recommended. The patient subsequently developed a cutaneous lower abdominal mass that was diagnosed as an osteosarcoma. Meanwhile, the petrous apex tumor continued to grow despite treatment until the patient died from the burden of disease. Temporal bone osteoblastomas and osteosarcomas are both extremely rare, and they can be difficult to differentiate histologically. Our case illustrates this difficulty and demonstrates the possibility of a high-grade osteoblastoma's malignant conversion to an osteosarcoma.

Metastatic osteosarcoma: a challenging multidisciplinary treatment

Osteosarcoma is the most common malignant bone tumor, currently treated with pre-and postoperative chemotherapy in association with the surgical removal of the tumor. About 15-20% of patients have evidence of metastases at diagnosis, mostly in the lungs. Patients with metastatic disease still have a very poor prognosis, with approximately 20-30% of long-term survivors, as compared with 65-70% of patients with localized disease. The optimum management of these patients has not been standardized yet due to several patterns of metastatic disease harboring different prognosis. Complete surgical resection of all sites of disease is mandatory and predictive of survival. Patients with multiple sites of disease not amenable to complete surgery removal should be considered for innovative therapeutic approaches because of poor prognosis.

Radiotherapy and gemcitabine-docetaxel chemotherapy in children and adolescents with unresectable recurrent or refractory osteosarcoma

OBJECTIVE

Few reports have described the treatment outcome of osteosarcoma using radiotherapy. We evaluated the efficacy of radiotherapy and gemcitabine and docetaxel chemotherapy for patients with unresectable recurrent or refractory osteosarcoma.

METHODS

Data from six patients (five male, one female) who received radiotherapy and gemcitabine and docetaxel chemotherapy at the Korea Cancer Center Hospital were retrospectively reviewed. Tumor response was evaluated according to metabolic changes using (18)F-fluorodeoxy-D-glucose-positron emission tomography.

RESULTS

The median age of the patients was 15.0 years (range, 14.0-15.8 years). Two patients had single bone lesions, and four had multiple metastatic bone lesions. Patients received a median 3.5 courses of gemcitabine and docetaxel chemotherapy (range, 2-6 courses). The median dose of radiotherapy was 50.0 Gy (range, 46-84 Gy). There were two complete metabolic responses and one partial metabolic response. The objective response rate was 50.0% (3/6). Responses were maintained for 4.6, 6.1 and 13.7 months, respectively. Patients were followed up for a median of 5.8 months (range, 2.7-84.6 months), and the median progression-free survival after this treatment was 3.6 months (range, 1.1-13.7 months). At the time of analysis, two patients were alive, one was lost to follow-up and three had died.

CONCLUSION

Radiotherapy with gemcitabine and docetaxel chemotherapy showed some improvement in cases of refractory tumors or multiple bone metastases. Further studies are needed to investigate the efficacy of newer radiotherapy modalities, as well as to identify new radiosensitizing chemotherapy regimens.

Canine osteosarcoma: a naturally occurring disease to inform pediatric oncology

Osteosarcoma (OSA) is the most common form of malignant bone cancer in children and dogs, although the disease occurs in dogs approximately 10 times more frequently than in people. Multidrug chemotherapy and aggressive surgical techniques have improved survival; however, new therapies for OSA are critical, as little improvement in survival times has been achieved in either dogs or people over the past 15 years, even with significant efforts directed at the incorporation of novel therapeutic approaches. Both clinical and molecular evidence suggests that human and canine OSA share many key features, including tumor location, presence of microscopic metastatic disease at diagnosis, development of chemotherapy-resistant metastases, and altered expression/activation of several proteins (e.g. Met, ezrin, phosphatase and tensin homolog, signal transducer and activator of transcription 3), and p53 mutations, among others. Additionally, canine and pediatric OSA exhibit overlapping transcriptional profiles and shared DNA copy number aberrations, supporting the notion that these diseases are similar at the molecular level. This review will discuss the similarities between pediatric and canine OSA with regard to histology, biologic behavior, and molecular genetic alterations that indicate canine OSA is a relevant, spontaneous, large animal model of the pediatric disease and outline how the study of naturally occurring OSA in dogs will offer additional insights into the biology and future treatment of this disease in both children and dogs.

Does amputation offer any survival benefit over limb salvage in osteosarcoma patients with poor chemonecrosis and close margins?

A poor response to chemotherapy (≤ 90% necrosis) for osteosarcomas leads to poorer survival and an increased risk of local recurrence, particularly if there is a close margin of excision. We evaluated whether amputation confers any survival benefit over limb salvage surgery (LSS) with narrow margins in patients who respond poorly to chemotherapy.

We only analysed patients with an osteosarcoma of the limb, a poor response to chemotherapy and close margins on LSS (marginal/intralesional) or primary amputation: 360 patients (36 LSS (intralesional margins), 197 LSS (marginal margins) and 127 amputations) were included. Local recurrence developed in 13 (36%) following LSS with intralesional margins, and 39 (20%) following LSS with marginal margins. There was no local recurrence in patients who underwent amputation. The five-year survival for all patients was 41% (95% confidence interval (CI) 35 to 46), but for those treated by LSS with marginal margins was 46.2% (95% CI 38 to 53), 36.3% (95% CI 27 to 45) for those treated by amputation, and 28% (95 CI 14 to 44) for those treated by LSS with intralesional margins. Patients who had LSS and then developed local recurrence as a first event had the same survival as those who had primary amputation without local recurrence. Prophylactic adjuvant radiotherapy was used in 40 patients but had no discernible effect in preventing local recurrence.

Although amputation offered better local control, it conferred no clear survival benefit over LSS with marginal margins in these patients with a poor overall prognosis.

Cite this article: Bone Joint J 2015;97-B:115–20.

Stereotactic radiosurgery and fracture fixation in 6 dogs with appendicular osteosarcoma

OBJECTIVE

To evaluate clinical outcome of dogs with appendicular osteosarcoma (OSA) treated with stereotactic radiosurgery (SRS) and subsequent internal fixation of a pathologic fracture.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs with spontaneous-occurring appendicular OSA (n = 6).

METHODS

Medical records (May 2002-January 2008) of dogs that had SRS for appendicular OSA were reviewed. Dogs were included if they had a pathologic fracture either before or after SRS and were treated with internal fixation. Signalment, history, physical examination findings, clinicopathologic data, diagnostic imaging findings, biopsy results, surgical complications, number of surgeries, adjuvant therapy, development of metastatic disease and cause of death were recorded.

RESULTS

Six dogs met the inclusion criteria. Two dogs had a pathologic fracture at admission and 4 dogs developed a fracture after SRS with a mean ± SD time to fracture development of 6.25 ± 1.65 months. The first 3 fractures were repaired using an open approach and the latter three using minimally invasive percutaneous osteosynthesis (MIPO). Infection occurred in 5 dogs and implant failure in 3. Limb function was subjectively assessed as good in all dogs when the implants were stable and infections were subclinical. Survival times ranged from 364-897 days; 1 dog was lost to follow-up.

CONCLUSIONS

Fracture repair using internal fixation should be considered a viable limb-sparing alternative for pathologic fractures that have been treated with SRS.

Repair of radiation damage of U2OS osteosarcoma cells is related to DNA-dependent protein kinase catalytic subunit (DNA-PKcs) activity

The present study was to investigate the effects of DNA-PKcs deficiencies on radiation sensitivity of human osteosarcoma U2OS cells to γ-ray and to explore the underlying molecular mechanism. In vitro, U2OS cells were transfected with different DNA-PKcs siRNAs or control siRNAs to establish stably siRNA-transfected cell lines U2OS-Si and U2OS-Sc, respectively. Cell viability and apoptosis after irradiation were analyzed using cell counting kit (CCK-8) and flow cytometric assay, respectively. Expressions of apoptosis-related and oxidative stress-responded proteins were assessed using Western blot. The tumorigenesis activity was examined in nude mice xenograft osteosarcoma mode. Results showed that DNA-PKcs siRNA significantly could inhibit U2OS viability and cell proliferation after exposure to irradiation. Compared with the U2OS and U2OS-Sc cells, the U2OS-Si cells induced higher apoptosis rate and loss of mitochondrial membrane potentials, accompanying with more reactive oxygen species (ROS) and malondialdehyde (MDA) production, increased DNA double-strand breaks (DSBs) induced by irradiation. Protein levels of the anti-apoptotic Bcl-2 were downregulated most obviously in U2OS-Si cells after irradiation, while pro-apoptotic factor Bax and caspase-3 upregulated. Moreover, the antioxidants protein expression levels of Nuclear factor-erythroid 2-related factor 2 (Nrf2) and its target heme oxygenase-1 (HO-1) were also significantly reduced in parallel to DNA-PKcs inhibition in U2OS-Si cells. In nude mice xenograft model, DNA-PKcs siRNA remarkably inhibited tumor growth and dissemination. In conclusion, DNA-PKcs siRNA might have a potential for osteosarcoma treatment by sensitizing osteosarcoma cells to γ-ray through modulation on oxidative stress-mediated DNA DSBs repair and mitochondrial pathway apoptosis.

Bone-seeking radiopharmaceuticals as targeted agents of osteosarcoma: samarium-153-EDTMP and radium-223

Osteosarcoma is a cancer characterized by formation of bone by malignant cells. Routine bone scan imaging with Tc-99m-MDP is done at diagnosis to evaluate primary tumor uptake and check for bone metastases. At time of relapse the Tc-99m-MDP bone scan also provides a specific means to assess formation of bone by malignant osteosarcoma cells and the potential for bone-seeking radiopharmaceuticals to deliver radioactivity directly into osteoblastic osteosarcoma lesions. This chapter will review and compare a bone-seeking radiopharmaceutical that emits beta-particles, samarium-153-EDTMP, with an alpha-particle emitter, radium-223. The charged alpha particles from radium-223 have far more mass and energy than beta particles (electrons) from Sm-153-EDTMP. Because radium-223 has less marrow toxicity and more radiobiological effectiveness, especially if inside the bone forming cancer cell than samarium-153-EDTMP, radium-223 may have greater potential to become widely used against osteosarcoma as a targeted therapy. Radium-223 also has more potential to be used with chemotherapy against osteosarcoma and bone metastases. Because osteosarcoma makes bone and radium-223 acts like calcium, this radiopharmaceutical could possibly become a new targeted means to achieve safe and effective reduction of tumor burden as well as facilitate better surgery and/or radiotherapy for difficult to resect large, or metastatic tumors.

Osteosarcoma treatment - where do we stand? A state of the art review

Long-term outcome for patients with high-grade osteosarcoma has improved with the addition of systemic chemotherapy, but subsequent progress has been less marked. Modern, multiagent, dose-intensive chemotherapy in conjunction with surgery achieves a 5-year event-free survival of 60-70% in extremity localized, non-metastatic disease. A major, as yet unsolved, problem is the poor prognosis for metastatic relapse or recurrence, and for patients with axial disease. This article reviews the current state of the art of systemic osteosarcoma therapy by focusing on the experiences of cooperative osteosarcoma groups. Also, we shed light on questions and challenges posed by the aggressiveness of the tumor, and we consider potential future directions that may be critical to progress in the prognosis of high-grade osteosarcoma.

Current therapeutic strategies and novel approaches in osteosarcoma

Osteosarcoma is the most frequent malignant primary bone tumor and a main cause of cancer-related death in children and adolescents. Although long-term survival in localized osteosarcoma has improved to about 60% during the 1960s and 1970s, long-term survival in both localized and metastatic osteosarcoma has stagnated in the past several decades. Thus, current conventional therapy consists of multi-agent chemotherapy, surgery and radiation, which is not fully adequate for osteosarcoma treatment. Innovative drugs and approaches are needed to further improve outcome in osteosarcoma patients. This review describes the current management of osteosarcoma as well as potential new therapies.

The Current and Future Therapies for Human Osteosarcoma

Osteosarcoma (OS) is the most common non-hematologic malignant tumor of bone in adults and children. As sarcomas are more common in adolescents and young adults than most other forms of cancer, there are a significant number of years of life lost secondary to these malignancies. OS is associated with a poor prognosis secondary to a high grade at presentation, resistance to chemotherapy and a propensity to metastasize to the lungs. Current OS management involves both chemotherapy and surgery. The incorporation of cytotoxic chemotherapy into therapeutic regimens escalated cure rates from <20% to current levels of 65-75%. Furthermore, limb-salvage surgery is now offered to the majority of OS patients. Despite advances in chemotherapy and surgical techniques over the past three decades, there has been stagnation in patient survival outcome improvement, especially in patients with metastatic OS. Thus, there is a critical need to identify novel and directed therapy for OS. Several Phase I trials for sarcoma therapies currently ongoing or recently completed have shown objective responses in OS. Novel drug delivery mechanisms are currently under phase II and III clinical trials. Furthermore, there is an abundance of preclinical research which holds great promise in the development of future OS-directed therapeutics. Our continuously improving knowledge of the molecular and cell-signaling pathways involved in OS will translate into more effective therapies for OS and ultimately improved patient survival. The present review will provide an overview of current therapies, ongoing clinical trials and therapeutic targets under investigation for OS.

Co-nanoencapsulated doxorubicin and Dz13 control osteosarcoma progression in a murine model

Objectives

Chitosan is a green (natural, abundant, biodegradable, biocompatible) biopolymer that can be formulated to encapsulate a variety of therapeutic compounds. This study aimed to investigate chitosan nanoparticles (NPs) as a means of improving delivery of the clinically used anti-cancer agent doxorubicin (Dox) and the preclinical lead compound Dz13 oligonucleotide together.

Methods

A novel chitosan NP system encapsulating Dox and Dz13 was designed, biophysically characterised and tested in a clinically relevant model of the metastasising bone tumour, osteosarcoma (OS).

Key findings

By careful alteration of the concentration of the individual components, a final formulation of Dz13-Dox NPs (DDNPs) was achieved, with high (&gt;91%) loading of both compounds, which consisted of individual 50-nm particles forming aggregates as large as 500 nm, with a large positive ζ-potential. The DDNPs could be stored at various temperatures for a week without loss in activity but were prone to degradation in serum. DDNPs successfully inhibited OS tumour growth more effectively than treatment with NPs of Dz13 and Dox-chitosan, as well as Dox administered intraperitoneally. Apart from inhibiting tumour growth, DDNPs protected the affected bone from substantial destruction by aggressive tumour growth and reduced the incidence of metastasis to the lungs without causing adverse effects in mice.

Conclusion

This NP is a promising formulation that could be useful for clinical management of OS.

Proton-based radiotherapy for unresectable or incompletely resected osteosarcoma

BACKGROUND

A study was undertaken to assess clinical outcome and the role of proton therapy for local control of osteosarcoma (OSA).

METHODS

All patients who received proton therapy or mixed photon-proton radiotherapy from 1983 to 2009 at the Massachusetts General Hospital were reviewed. Criteria for proton therapy were the need for high dose in the context of highly conformal radiotherapy of unresected or partially resected OSA, positive postoperative margins, postoperative imaging studies with macroscopic disease, or incomplete resection as defined by the surgeon. The primary endpoint was local control of the site treated; secondary endpoints were disease-free survival (DFS), overall survival (OS), long-term toxicity, and prognostic factors associated with clinical outcome.

RESULTS

Fifty-five patients with a median age of 29 years (range, 2-76 years) were offered proton therapy. The mean dose was 68.4 gray (Gy; standard deviation, 5.4 Gy). Of the total dose, 58.2% (range, 11%-100%) was delivered with protons. Local control after 3 and 5 years was 82% and 72%, respectively. The distant failure rate was 26% after 3 and 5 years. The 5-year DFS was 65%, and the 5-year OS was 67%. The extent of surgical resection did not correlate with outcome. Risk factors for local failure were ≥ 2 grade disease (P < .0001) and total treatment length (P = .008). Grade 3 to 4 late toxicity was seen in 30.1 % of patients. One patient died from treatment-associated acute lymphocytic leukemia, and 1 from secondary carcinoma of the maxilla.

CONCLUSIONS

Proton therapy to deliver high radiotherapy doses allows locally curative treatment for some patients with unresectable or incompletely resected OSA.

IGF1R-targeted therapy and its enhancement of doxorubicin chemosensitivity in human osteosarcoma cell lines

Type-I insulin-like growth factor receptor (IGF1R) and its signaling play an important role in osteosarcomagenesis, tumor progression, and chemoresistance. The purpose of this study was to investigate both the effect and mechanisms of IGF1R inhibition by tyrphostin AG1024 in the presence or absence of doxorubicin in a panel of six osteosarcoma cell lines and a self-established doxorubicin-resistant cell line. We are the first to indicate that targeting IGF1R together with doxorubicin achieved additive anti-osteosarcoma growth effect, accompanied with increased apoptosis, cytotoxicity, and dual cell cycle arrests. In conclusion, IGF1R inhibition can enhance doxorubicin chemotherapy in some osteosarcoma cell lines.

WEE1 inhibition sensitizes osteosarcoma to radiotherapy

Background

The use of radiotherapy in osteosarcoma (OS) is controversial due to its radioresistance. OS patients currently treated with radiotherapy generally are inoperable, have painful skeletal metastases, refuse surgery or have undergone an intralesional resection of the primary tumor. After irradiation-induced DNA damage, OS cells sustain a prolonged G₂ cell cycle checkpoint arrest allowing DNA repair and evasion of cell death. Inhibition of WEE1 kinase leads to abrogation of the G₂ arrest and could sensitize OS cells to irradiation induced cell death.

Methods

WEE1 expression in OS was investigated by gene-expression data analysis and immunohistochemistry of tumor samples. WEE1 expression in OS cell lines and human osteoblasts was investigated by Western blot. The effect of WEE1 inhibition on the radiosensitivity of OS cells was assessed by cell viability and caspase activation analyses after combination treatment. The presence of DNA damage was visualized using immunofluorescence microscopy. Cell cycle effects were investigated by flow cytometry and WEE1 kinase regulation was analyzed by Western blot.

Results

WEE1 expression is found in the majority of tested OS tissue samples. Small molecule drug PD0166285 inhibits WEE1 kinase activity. In the presence of WEE1-inhibitor, irradiated cells fail to repair their damaged DNA, and show higher levels of caspase activation. The inhibition of WEE1 effectively abrogates the irradiation-induced G₂ arrest in OS cells, forcing the cells into premature, catastrophic mitosis, thus enhancing cell death after irradiation treatment.

Conclusion

We show that PD0166285, a small molecule WEE1 kinase inhibitor, can abrogate the G₂ checkpoint in OS cells, pushing them into mitotic catastrophe and thus sensitizing OS cells to irradiation-induced cell death. This suggests that WEE1 inhibition may be a promising strategy to enhance the radiotherapy effect in patients with OS.