Localized Osteosarcoma Research Articles

Immune checkpoint-regulatable hydrogel-immobilized nanotherapeutics for post-surgical treatment of osteosarcoma

Osteosarcoma recurrence following surgical resection is notoriously prevalent and resistant to chemotherapy (i.e., doxorubicin, DOX) due to its intricate immunosuppressive tumor microenvironment, which remains one of the most life-threatening tumors. In this study, we report the fabrication of an in-situ injectable hydrogel-immobilized nanotherapeutics, tailored to stimulate tumoricidal immunity, thus mitigate both localized osteosarcoma recurrence and the propagation of metastatic tumors subsequent to surgical intervention. Zeolitic imidazolate framework-8 nanoparticles (ZIF NPs), encapsulating a chemotherapeutic agent (i.e., DOX) and immunotherapeutic agents (i.e., αPDL1 and αCD47), are loaded in fibrin hydrogels. These bioengineered constructs are judiciously deployed at surgical sites to orchestrate chemo-immunotherapeutic interventions, effectuated through the controlled release of doxorubicin and the initiation of T cell-mediated immune responses. DOX has the capability to eradicate tumor cells and initiate immunogenic cell death. Notably, αPDL1 engenders the circumvention of PDL1-mediated resistance and dominates metastatic tumor expansion, thereby exerting a pivotal role in the context of systemic immunosuppression. αCD47 blocks the ‘don’t eat me’ signaling axis intrinsic to cancer cells, thereby potentiating their phagocytosis by macrophages. This orchestrated blockade synergistically activates the host immune milieu, thereby repressing tumor recurrence and curtailing the growth of metastatic lesions post-surgical resection in the subcutaneous tumor model (lateral and bilateral) and tibial tumor model (orthotopic and metastatic), respectively. Additionally, zinc ions from the degradation of ZIF NPs acts as the stimulator of interferon genes (STING) agonists to enhance the immunotherapeutic activity against distal and metastatic tumors. The reported immune checkpoint-regulatable cancer immunotherapy activates the host innate and adaptive immune systems, which shows promising for the treatment of osteosarcoma patients.

Alterations in Serum Lipids and Lipoproteins Induced by Neoadjuvant Chemotherapy in Patients with Osteosarcoma around the Knee Joint: A Retrospective Analysis.

To investigate the serum lipid profiles of patients with localized osteosarcoma around the knee joint before and after neoadjuvant chemotherapy. After retrospectively screening the data of 742 patients between January 2007 and July 2020, 50 patients aged 13 to 39 years with Enneking stage II disease were included in the study. Serum lipid levels, including total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), lipoprotein-α [Lp(a)], and apolipoprotein A1, B, and E (ApoA1, ApoB, and ApoE), and clinicopathological characteristics were collected before and after neoadjuvant chemotherapy. The mean levels of TC, TG, and ApoB were significantly increased following neoadjuvant chemotherapy (16%, 38%, and 20%, respectively, vs. pretreatment values; P<0.01). The mean levels of LDL-C and ApoE were also 19% and 16% higher, respectively (P<0.05). No correlation was found between the pretreatment lipid profile and the histologic response to chemotherapy. An increase in Lp(a) was strongly correlated with the Ki-67 index (R=0.31, P=0.023). Moreover, a trend toward longer disease-free survival (DFS) was observed in patients with decreased TG and increased LDL-C following chemotherapy, although this difference was not statistically significant (P=0.23 and P=0.24, respectively). Significant elevations in serum lipids were observed after neoadjuvant chemotherapy in patients with localized osteosarcoma. There was no prognostic significance of pretreatment serum lipid levels on histologic response to neoadjuvant chemotherapy. The scale of increase in serum Lp(a) might have a potential prognostic role in osteosarcoma. Patients with increased LDL-C or reduced TG after chemotherapy seem to exhibit a trend toward favorable DFS.

Long term survival in adult osteosarcoma patients treated with a two-drug regimen: Final results of the OSAD93 phase II study of the FSG-GETO

RationaleWe report a phase II trial (OSAD93) testing CDDP with ifosfamide (IFO), without doxorubicin in neoadjuvant phase, in adult osteosarcoma with a 25 years follow-up. Patients and methodsThis is a multicentric phase II study of neoadjuvant chemotherapy with IFO and CDDP in localized high-grade osteosarcoma of patients. Patients received 4 pre-operative courses of IFO 9 g/m2 and CDDP 100 mg/m2 on day 4 (SHOC regimen), followed by local treatment. Doxorubicin was added post-operatively (HOCA regimen) in patients with > 10 % residual tumor cells. A Good Histological Response (GHR), ie ≤ 10 % residual tumor cells in > 30 % of patients, was the primary objective. Disease-free survival (DFS), overall survival (OS) and toxicity were secondary objectives. ResultsFrom Jan 1994 to Jun 1998, 60 patients were included. Median age was 27 (range: 16–63). Primary tumor sites were limbs (76 %), trunk, head or neck (24 %). After neoadjuvant SHOC, grade 3–4 and febrile neutropenia, thrombopenia, and re-hospitalization occurred in 58 %, 17 %, 17 % and 22 % of SHOC courses and in 76 %, 28 %, 47 %, 47 % of HOCA courses, respectively. GHR was obtained in 16/60 (27.5 %) patients. With a median follow-up of 322 months, the DFS and OS were 51.8 % and 64.4 % at 5 years. At 10 years, DFS and OS were 49.9 % and 64.4 %. At 25 years, DFS and OS were 47.8 % and 55.9 %. No long-term cardiac toxicity was observed. Three patients developed a second malignancy (one fatal) after 300 months. ConclusionThough the primary endpoint of OSAD93 was not met, this pre-operative doxorubicin-free regimen led to excellent long-term survival with limited toxicity in localized osteosarcoma.

Updated results from ALTER-S002: A single-arm multicenter trial of the combination of anlotinib with chemotherapy in patients with stage IIB classic osteosarcoma of the extremity.

11529 Background: The overexpression of multiple tyrosine kinase receptors in osteosarcoma indicated a promising therapy targeting these receptors. Anlotinib is a multi-targeted tyrosine kinase inhibitor that potentially inhibits tumor angiogenesis. The combination of anti-angiogenic drugs with chemotherapeutic agents is proposed to act synergistically to achieve favorable tumor control, especially as the neoadjuvant therapy. We had reported the neoadjuvant therapy data of anlotinib in combination with chemotherapy for treatment-naive stage IIB classical osteosarcoma of the extremity in the 2023 ESMO congress. Here we report an update on the effectiveness and safety of the follow-up. Methods: In this open-label, single-arm, multicenter phase II clinical trial. Eligible patients(pts) were aged 12-40 years with histologically confirmed primary localized extremity classic osteosarcoma, stage IIB, operable. Pts received anlotinib (10mg, po, d1-14, q3w), doxorubicin (A) (20-25mg/m2 iv, d1-3, q3w) and cisplatin (P) (70-90mg/m2, iv, d1, q3w) for the first nine weeks. Pts underwent radical surgery after the exclusion of contraindications at week 10. After surgery, pts received A+P at weeks 12-14, and anlotinib plus A+P at weeks 15-20 with the drug dose unchanged. Since week 21, anlotinib (12mg, po, d1-14, q3w) monotherapy was maintained until week 104 or the occurrence of an EFS event. The primary endpoint was 24-month EFS rate, secondary endpoints were 36-month EFS rate, local recurrence rate, lung metastasis rate, 3-year OS rate and safety. Results: From May 2020 to Apr 2022, 52 eligible pts were enrolled, while 51 pts underwent surgery after 3 cycles of neoadjuvant therapy. At the data cut-off date (Oct. 2023), the median EFS was not reached, 12 and 24-month EFS rates were 84.18% (95% CI :70.82, 91.77) and 73.43% (95% CI :57.40, 84.21), respectively. The stratified analysis of EFS showed that the length and diameter of the target lesion are independent prognostic factors. The median OS was not reached, the 24-month OS rate was 95.92% (95% CI :84.65, 98.96). Among the 51 pts who underwent surgical treatment, 12(23.53%, 95% CI: 12.79, 37.49) pts experienced recurrence or metastasis. Most treatment-related adverse events (TRAEs) were grade 1-2. Grade 3/4 TRAEs (≥20%) included neutropenia (51.92%), leukopenia (38.46%), thrombocytopenia (36.54%) and anemia (32.69%). Conclusions: The updated results suggested that anlotinib combined with doxorubicin and cisplatin in the perioperative period showed favorable efficiency and manageable adverse events in Stage IIB classic osteosarcoma of the extremity. Clinical trial information: ChiCTR 2000033298.

Prospective evaluation of pre-treatment ctDNA burden in localized osteosarcoma to identify patients with inferior outcomes: A report from the LEOPARD study.

Prospective evaluation of pre-treatment ctDNA burden in localized osteosarcoma to identify patients with inferior outcomes: A report from the LEOPARD study.

Glycan Structures in Osteosarcoma as Targets for Lectin-Based Chimeric Antigen Receptor Immunotherapy.

Osteosarcoma is a type of bone cancer that primarily affects children and young adults. The overall 5-year survival rate for localized osteosarcoma is 70-75%, but it is only 20-30% for patients with relapsed or metastatic tumors. To investigate potential glycan-targeting structures for immunotherapy, we stained primary osteosarcomas with recombinant C-type lectin CD301 (MGL, CLEC10A) and observed moderate to strong staining on 26% of the tumors. NK92 cells expressing a CD301-CAR recognized and eliminated osteosarcoma cells in vitro. Cytotoxic activity assays correlated with degranulation and cytokine release assays. Combination with an inhibitory antibody against the immune checkpoint TIGIT (T-cell immunoreceptor with lg and ITIM domains) showed promising additional effects. Overall, this study showed, for the first time, the expression of CD301 ligands in osteosarcoma tissue and demonstrated their use as potential target structures for lectin-based immunotherapy.

Identification of an early survival prognostic gene signature for localized osteosarcoma patients

Osteosarcoma is the most prevalent bone tumor in pediatric patients. Neoadjuvant chemotherapy has improved osteosarcoma patient survival, however the 5-year survival rate for localized osteosarcoma is 75% with a 30–50% recurrence rate. We, therefore, sought to identify a prognostic gene signature which could predict poor prognosis in localized osteosarcoma patients. Using the TARGET osteosarcoma transcriptomic dataset, we identified a 13-hub gene signature associated with overall survival and time to death of localized osteosarcoma patients, with the high-risk group showing a 22% and the low-risk group showing 100% overall survival. Furthermore, network analysis identified five modules of co-expressed genes that significantly correlated with survival, and identified 65 pathways enriched across 3 modules, including Hedgehog signaling, which includes 2 of the 13 genes, IHH and GLI1. Subsequently, we demonstrated that GLI antagonists inhibited growth of a recurrent localized PDX-derived cell line with elevated IHH and GLI1 expression, but not a non-relapsed cell line with low pathway activation. Finally, we show that our signature outperforms previously reported signatures in predicting poor prognosis and death within 3 years in patients with localized osteosarcoma.

Histopathological Response to Neoadjuvant Chemotherapy in Patients With Enneking Stage II Conventional Osteosarcoma of Extremities: A Retrospective-Single Institution Study in Vietnam.

The standard treatment for localized osteosarcoma is neoadjuvant chemotherapy before surgery, followed by adjuvant chemotherapy. Our aim was to report the rate of histopathological response to neoadjuvant chemotherapy for the treatment of extremity osteosarcoma in Vietnam. We performed a retrospective study of stage II conventional osteosarcoma patients under 40years-old who received MAP regimen as neoadjuvant chemotherapy at the Vietnam National Cancer Hospital between June 2019 and June 2022. Histopathological response was evaluated using the Huvos grading system, in which a good histopathological response was defined as a necrotic rate of 90% or more. Thirty-five eligible patients were included in the study. Male patients accounted for 65.7%, with a median age of 16 years (range, 8-38years). Of the 35 cases, 31 were reported as stage IIB (88.6%). The femur and tibia were the most common sites in our study, accounting for 51.4% and 34.3%, respectively. The most common pathologic subtype was osteoblastic osteosarcoma (68.6%), followed by chondroblastic subtype (20%). After two cycles of MAP-regimen neoadjuvant chemotherapy, 28 of 35 patients (80%) underwent limb-sparing surgery. A good histopathological response was observed in 18 of 35 patients (51.4%). There were significant correlations between the duration of symptoms (P = 0.016), LDH (P = 0.001) serum levels at initial presentation, and ALP (P = 0.043) serum levels at initial presentation with histopathological response. This retrospective study suggests a possible association between symptom duration, pre-treatment LDH levels, and pre-treatment ALP levels with histopathological response rates. Additional clinical investigations with long-term follow-up are needed to investigate survival outcomes in the Asian population.

Children's Oncology Group's 2023 blueprint for research: Bone tumors.

The Children's Oncology Group (COG) Bone Tumor Committee is responsible for clinical trials and biological research on localized, metastatic, and recurrent osteosarcoma and Ewing sarcoma (EWS). Results of clinical trials in localized disease completed and published in the past 10 years have led to international standard-of-care chemotherapy for osteosarcoma and EWS. A recent focus on identifying disease subgroups has led to the identification of biological features associated with poor outcomes including the presence of circulating tumor DNA (ctDNA) at diagnosis, and specific genomic alterations-MYC amplification for osteosarcoma and STAG2 and TP53 mutation for EWS. Studies validating these potential biomarkers are under way. Clinical trials evaluating the addition of multitargeted kinase inhibitors, which are active in relapsed bone sarcomas, to standard chemotherapy are under way in osteosarcoma and planned in EWS. In addition, the Committee has data analyses and a clinical trial under way to evaluate approaches to local management of the primary tumor and metastatic sites. Given the rarity of bone sarcomas, we have prioritized international interactions and are in the process of forming an international data-sharing consortium to facilitate refinement of risk stratification and study of rare disease subtypes.

A pilot exome sequencing study suggests that germline variants influence methotrexate-induced toxicities in pediatric patients with localized osteosarcoma.

Osteosarcoma (OS) is a rare pediatric cancer for which therapeutic approaches, including chemotherapy and surgery, show a wide interindividual variability in patient response, both in terms of adverse events and therapy efficacy. There is growing evidence that this individual variable response to therapies is also influenced by inherited genetic variations. However, the results obtained to date in these pediatric cancers have been contradictory and often lack validation in independent series. Additionally, these studies frequently focused only on a limited number of polymorphisms in candidate genes. In order to identify germline coding variations associated with individual differences in adverse events occurrence in pediatric patients affected by localized OS, we carried out an exome-wide association study in 24 OS patients treated with methotrexate, cisplatin, and doxorubicin, using the SNP-Set (Sequence) Kernel Association Test (SKAT), optimized for small sample size. Gene sets significantly associated (FDR<.05) with neutropenia and hepatotoxicity induced by methotrexate were identified. Some of the identified genes map in loci previously associated with similar phenotypes (e.g., leukocyte count, alkaline phosphatase levels). Further studies in larger series and with functional characterization of the identified associations are needed; nonetheless, this pilot study prompts the relevance of broadly investigating variants along the whole genome, to identify new potential pharmacogenes, beyond drug metabolism, transport, and receptor candidate genes.

Osteosarcoma: Current Concepts and Evolutions in Management Principles.

Osteosarcoma is a rare malignancy arising from mesenchymal tissue, and represents the most common bone sarcoma. The management of osteosarcoma is challenging, and requires a multidisciplinary approach. In daily clinical practice, surgery, radiotherapy, and conventional chemotherapy constitute the therapeutic armamentarium against the disease. However, a significant number of patients with initially localized osteosarcoma will experience local or distant recurrence, and the prognosis for metastatic disease remains dismal. There is a pressing need to identify novel therapeutic strategies to better manage osteosarcoma and improve survival outcomes. In this study, we present recent advances in the therapeutic management of osteosarcoma, including surgical and medical advances. The role of immunotherapy (immune checkpoint inhibitors, adoptive cellular therapy, cancer vaccines) and other targeted therapies including tyrosine kinase inhibitors is discussed; however, additional studies are required to delineate their roles in clinical practice.

Clinical Targeted Next-Generation Panel Sequencing Reveals MYC Amplification Is a Poor Prognostic Factor in Osteosarcoma.

Osteosarcoma risk stratification, on the basis of the presence of metastatic disease at diagnosis and histologic response to chemotherapy, has remained unchanged for four decades, does not include genomic features, and has not facilitated treatment advances. We report on the genomic features of advanced osteosarcoma and provide evidence that genomic alterations can be used for risk stratification. In a primary analytic patient cohort, 113 tumor and 69 normal samples from 92 patients with high-grade osteosarcoma were sequenced with OncoPanel, a targeted next-generation sequencing assay. In this primary cohort, we assessed the genomic landscape of advanced disease and evaluated the correlation between recurrent genomic events and outcome. We assessed whether prognostic associations identified in the primary cohort were maintained in a validation cohort of 86 patients with localized osteosarcoma tested with MSK-IMPACT. In the primary cohort, 3-year overall survival (OS) was 65%. Metastatic disease, present in 33% of patients at diagnosis, was associated with poor OS (P = .04). The most frequently altered genes in the primary cohort were TP53, RB1, MYC, CCNE1, CCND3, CDKN2A/B, and ATRX. Mutational signature 3 was present in 28% of samples. MYC amplification was associated with a worse 3-year OS in both the primary cohort (P = .015) and the validation cohort (P = .012). The most frequently occurring genomic events in advanced osteosarcoma were similar to those described in prior reports. MYC amplification, detected with clinical targeted next-generation sequencing panel tests, is associated with poorer outcomes in two independent cohorts.

First-in-Maintenance Therapy for Localized High-Grade Osteosarcoma: An Open-Label Phase I/II Trial of the Anti-PD-L1 Antibody ZKAB001.

We investigated the safety and preliminary efficacy of anti-PD-L1 antibody (ZKAB001) as maintenance therapy for localized patients with high-grade osteosarcoma to reduce the risk of recurrence and metastasis. This open-label Phase I/II study was divided into dose-escalation Phase I and expansion Phase II. Phase I used a 3+3 design with ZKAB001 at three escalating doses ranging: 5, 10, 15 mg/kg every 2 weeks in 9 patients with localized high-grade osteosarcoma and Phase II tested 10 mg/kg in 12 patients for up to 24 cycles. Primary endpoints were safety and tolerability assessed using CTCAE4.0.3. Between October 2018 and 2019, 21 eligible patients were enrolled and accepted ZKAB001 treatment: 9 in the dose-escalation phase, and 12 in expansion phase. Six patients with disease progression withdrew from this study and follow-up is ongoing. The MTD was not defined in Phase I. All doses had a manageable safety profile. The recommended dose in Phase II was set at 10 mg/kg. Most frequent immune-related adverse events were thyroiditis (76.2%) and dermatitis (42.9%). Only 1 (4.8%) of 21 patients had a Grade 3 skin rash. The median 3-year event-free survival (EFS) and overall survival (OS) were not established; however, 24-month EFS was 71.4% (95% confidence interval, 47.2-86.0) and 2-year OS was 100%. Preliminary efficacy data showed EFS benefits in patients with PD-L1 positive or an MSI-H sub-population. Switching to maintenance using ZKAB001 showed an acceptable safety profile and provided preliminary evidence of clinical activity in localized patients with osteosarcoma.

Fatal heart disease in patients with bone and soft tissue sarcoma.

Background/purposeWith improved cancer survivorship, non-cancer events, especially heart disease (HD), have become the underlying cause of death in cancer patients, but the risk of HD mortality in sarcoma patients remains poorly characterized. Therefore, our purpose was to: (1) identify sarcoma patients at the highest risk of fatal HD compared with the general population, (2) identify patients and sarcoma characteristics associated with a higher risk of HD death, and (3) determine if chemotherapy increased the risk of HD death in sarcoma patients.MethodsFrom 1975 to 2016, we identified patients diagnosed with bone and soft tissue sarcoma from the Surveillance, Epidemiology, and End Results (SEER) database in the US. Standardized mortality ratios (SMRs) were evaluated using mortality data from the general population collected by the National Center for Health Statistics. This was the largest retrospective cohort study of fatal HD in individuals with sarcoma.ResultsIn 80,905 sarcoma patients observed for 530,290 person-years, 3,350 deaths from HD were identified with a mortality of 631.7/100,000 person-years. The SMR of death from HD was 1.38 (95% CI: 1.33–1.42). The highest risks of death from HD were observed in patients with Ewing sarcoma (SMR = 5.44; 95% CI: 3.38–8.75) and osteosarcoma (SMR = 1.92; 95% CI: 1.55–2.38). Patients diagnosed at < 19 years old had the highest SMR in all age subgroups, and a higher risk of fatal HD relative to the general population was observed in sarcoma survivors diagnosed at < 85 years old. In patients diagnosed at < 19 years old, HD plurality occurred in those with Ewing sarcoma (29.4%) and osteosarcoma (32.4%) and at > 35 years old, HD plurality occurred in those diagnosed with liposarcoma (19.0%) and malignant fibro histiocytoma (MFH) (23.6%). For sarcoma survivors, HD mortality risks were highest within the first year after diagnosis (SMR = 1.31; 95% CI: 1.21–1.41), and this risk remained elevated throughout follow-up compared with the general population. Subgroup analyses indicated that chemotherapy significantly increased the risk of fatal HD in patients with localized osteosarcoma (Hazard ratio (HR) = 3.18; 95% CI: 1.24–8.13; P = 0.016), but not in patients with other histological sarcoma subtypes and clinical stages.ConclusionThe risk of death from HD mainly varied in patients with different histological sarcoma subtypes and clinical stages. Chemotherapy increased the risk of fatal HD in patients with localized osteosarcoma. To lower the risk of fatal HD in patients with sarcoma, we call for enhanced multidisciplinary cooperation, including cardiologists and orthopedic surgeons.

1508P Pre-treatment high serum alkaline phosphatase level as a prognostic factor for patients with localized extremity osteosarcoma: A retrospective analysis of adolescent and adult patients

The prognostic role of pre-treatment serum alkaline phosphatase (SAP) in patients with osteosarcoma has been investigated in previous studies, but the results are inconsistent. The purpose of this study was to evaluate prognostic factors, especially pre-treatment SAP level, in adolescent and adult patients with localized extremity osteosarcoma.

Abstract 6047: Identification of a 13 gene signature to predict survival in localized osteosarcoma

Abstract Osteosarcoma (OS) is the most prevalent bone tumor in pediatric patients. Regimens of neoadjuvant chemotherapy have improved survival of OS patients greatly, however the 5-year survival rate for localized OS is 75% with a 30-50% recurrence rate. We sought to identify genes which could predict chemo-response and survival in localized OS. The TARGET OS RNA-seq dataset was utilized to identify genes and pathways associated with localized patient relapse and survival. We identified 478 differentially expressed genes with a 1.5 FC and FDR &amp;lt; 0.05 common to overall survival and relapse We further performed string analysis to generate a protein-protein interaction network followed by hub analysis with Cytohubba using betweenness centrality and radiality measures. Combining the top 10 hub genes from these two methods resulted in a total of 13 genes: MYOM2, VEGFA, VCAM1, EGFR, MUC1, IHH, GLI1, GPC3, IGF2, GRIA1, GNG12, GNGT1 and C3. These 13 genes were used to stratify localized patients in the TARGET dataset into high-risk and low-risk tertiles. The low-risk group had 100% overall survival while the high-risk group had 44% 5-year survival (p=2e-4). We also found a significant correlation between the 13 genes and time to death in localized patients (p=0.04). Additionally, there was a significant difference in expression of the 13 genes between alive and deceased patients (p=2e-5) and patients who relapsed (p=1.5e-4). Overall, these data suggest that these 13 genes could predict relapse and overall survival in OS patients with localized disease in the TARGET cohort. We performed Weighted Gene Correlation Network Analysis (WGCNA) on the 478 overlapping genes and identified five modules, with our 13 genes split across these modules. All modules were also significantly correlated with vital status suggesting that the genes in our signature represent distinct sub-groups with possibly separate mechanisms. Over-representation analysis was performed for each module and while each module did have distinct pathways, there were 65 pathways which overlapped between 3 of the modules. Of particular interest was Hedgehog signaling, with 2 of our 13 genes, IHH and GLI1, key to Hedgehog signaling, and a Hedgehog pathway inhibitor, Gant-58, scored high in reversing the 478 gene signature as determined using Connectivity Map (Broad Institute). We tested Gant-58 against two PDX OS models. Gant-58 did not inhibit a non-relapsed, chemo sensitive localized PDX-derived cell line, but showed potent activity towards a recurrent localized PDX with elevated IHH and GLI1 expression (p&amp;lt;0.0001). In summary, we identified 13 genes that predict overall survival and relapse in localized OS patients. The 13 genes represent distinct modules of co-expressing genes that significantly correlate with survival. Furthermore, preliminary data indicate Hedgehog pathway has a key role in survival and recurrence of localized OS patients. Citation Format: Tajhal D. Patel, Kshiti Dholakia, Tanmay R. Gandhi, Rupa S. Kanchi, Sandra L. Grimm, Chenlian Fu, Jason T. Yustein, Cristian Coarfa. Identification of a 13 gene signature to predict survival in localized osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6047.

Limb salvage surgery has a higher complication rate than amputation but is still beneficial for patients younger than 10 years old with osteosarcoma of an extremity

Background/PurposeLimb preserving surgery for the treatment of patients with osteosarcoma younger than 10 years old is challenging and some authors have advocated amputation to reduce the risk of complications. The aim of this study was to compare the clinical outcomes and surgical complications of patients with osteosarcoma of the extremity aged <10 years old who were treated with limb salvage and amputation. Patients and methodsRetrospective review of patients aged <10 years old who were treated for primary osteosarcoma of bone between 2000 and 2018. ResultsWe analyzed 82 consecutive patients (32 males, 50 females; median age 8, range 3–9 yrs). Limb-salvage surgery (LSS; n = 65, 79%) and amputation (n = 17, 21%) were performed. Fourteen patients had metastasis at surgery. In patients without metastasis at surgery, the metastasis-free and overall survival rates at 5 years following LSS vs. amputation were 75% vs. 58% (p = 0.162) and 71% vs. 55% (p = 0.516), respectively. The 2-year and 5-year OS rates of the LSS and amputation groups of patients with metastasis at surgery were 88% versus 83% and 50% versus 0%, respectively (p = 0.180). The overall complication rates were 46% post-LSS with 31% requiring re-operation versus 12% post-amputation, with 6% requiring re-operation (p = 0.010). ConclusionThe prognosis of patients with localized osteosarcoma aged <10 years undergoing LSS is similar to those treated with amputation, but LSS is associated with a higher risk of complications and subsequent re-operation. Level of evidenceLevel III

The negative impact of local recurrence on overall survival in adult patients with extremity localized osteosarcoma

Osteosarcoma is the most common primary malignant bone tumour in adults and is usually located in long bones. Standard treatment consists of perioperative chemo-therapy and radical surgical resection. In the case of the extremity location, the gold standard is limb-sparing surgery using various reconstructive techniques. Our study analyzed 175 adult patients in MSTS I-III stage treated for extremity os-teosarcoma at our institution between 2000 and 2017. The median observation was 41 months (3-225 months). 111 patients were treated with limb-sparing surgery, 80 patients had tumour resection followed by endoprosthetic reconstruction, 31 patients had local resection without reconstruction and 64 patients underwent amputation. 5-year OS (overall survival) and DFS (disease-free survival) rates in the study group were 62% and 52%, respectively, and life expectancy was 136 months. Local recurrence occurred in 34 (19%) patients in the whole group, including 16 (17%) patients after reconstruction, 11 (35%) patients after local resection and 7 (10%) patients who had an amputation. In the group of patients with local recurrence, 5-year OS rate was 30%, statistically significantly worse than patients without recurrence (5-year OS 70%).

Intensity of perioperative analgesia but not pre-treatment pain is predictive of survival in dogs undergoing amputation plus chemotherapy for extremity osteosarcoma.

The purpose of this bi‐institutional retrospective study was to determine whether, in dogs treated with limb amputation and adjunctive chemotherapy for osteosarcoma, oncologic outcomes are impacted by either: (1) baseline cancer pain severity, or (2) the approaches used for perioperative pain management. Data were extracted from the medical records of 284 dogs that underwent both limb amputation and chemotherapy (carboplatin and/or doxorubicin) between 1997 and 2017 for localized (non‐metastatic) osteosarcoma of the appendicular skeleton. Kaplan–Meier survival curves and Cox proportional hazard (PH) models were used to determine the impact that retrospectively scored baseline pain levels (high vs. low) and various analgesic and local anaesthetic treatments had on both metastasis‐free survival and all‐cause mortality. For the entire population, the median disease free interval and median overall survival times were 253 and 284 days, respectively. Baseline pain was rated as “low” in 84 dogs, and “high” in 190 dogs; pain severity had no detectable effect on either metastasis‐free survival or all‐cause mortality. When accounting for the potential influences of known prognostic factors, dogs treated with what was characterized as a high‐intensity perioperative analgesic plan (including both a non‐steroidal anti‐inflammatory drug [NSAID] and a bupivacaine‐eluting soaker catheter placed at the amputation site) had a higher probability of survival than dogs treated with a low‐intensity perioperative analgesic plan (neither an NSAID, nor a soaker catheter); the median overall survival times were 252 and 378 days, respectively (hazard ratio: 2.922; p = .020).

Exosomes as Efficient Nanocarriers in Osteosarcoma: Biological Functions and Potential Clinical Applications.

Osteosarcoma is the most common bone tumor affecting both adolescents and children. Although localized osteosarcoma has an overall survival of >70% in the clinic, metastatic, refractory, and recurrent osteosarcoma have poorer survival rates. Exosomes are extracellular vesicles released by cells and originally thought to be a way for cells to discard unwanted products. Currently, exosomes have been reported to be involved in intercellular cross-talk and induce changes in cellular behavior by transferring cargoes (proteins, DNA, RNA, and lipids) between cells. Exosomes regulate osteosarcoma progression, and processes such as tumorigenesis, proliferation, metastasis, angiogenesis, immune evasion, and drug resistance. Increasing evidences shows that exosomes have significant potential in promoting osteosarcoma progression and development. In this review, we describe the current research status of exosomes in osteosarcoma, focusing on the biological functions of osteosarcoma exosomes as well as their application in osteosarcoma as diagnostic biomarkers and therapeutic targets.