Treatment-Related Prognostic Factors in Managing Osteosarcoma around the Knee with Limb Salvage Surgery: A Lesson from a Long-Term Follow-Up Study

Surgery at specialised sarcoma centres improves patient outcomes - A systematic review by the Australia and New Zealand sarcoma association clinical practice guidelines working party

BACKGROUND

Optimal management of sarcoma requires multidisciplinary team input throughout the process of diagnosis, treatment and follow up. This systematic review aimed to evaluate the impact of surgery performed at specialised sarcoma centres on outcomes.

METHODS

A systematic review was conducted using the population, intervention, comparison and outcome (PICO) model. Medline, Embase, Cochrane Central databases were queried for publications that evaluated the local control, limb salvage rate, 30-day and 90-day surgical mortality, and overall survival in patients undergoing surgery in a specialist sarcoma centre compared with non-specialist centre. Each study was screened by two independent reviewers for suitability. A qualitative synthesis of the results was performed.

RESULTS

Sixty-six studies were identified. The majority of studies were Level III-3 as assessed by the NHMRC Evidence Hierarchy, whilst just over half of the studies were of good quality. Definitive surgery performed at specialised sarcoma centres was associated with improved local control as defined by lower rate of local relapse, higher rate of negative surgical margins, improved local recurrence free survival and higher limb conservation rate. Available evidences show a favourable pattern of lower 30-day and 90-day mortality rates, and greater overall survival when surgery was performed in specialist sarcoma centres compared with non-specialised centres.

CONCLUSIONS

Evidences support better oncological outcomes when surgery is performed at specialised sarcoma centre. Patients with suspected sarcoma should be referred early to a specialised sarcoma centre for multidisciplinary management, which includes planned biopsy and definitive surgery.

Biomaterials for Orthopaedic Diagnostics and Theranostics

Despite widespread use of conventional diagnostic methods in orthopaedic applications, limitations still exist in detection and diagnosing many pathologies especially at early stages when intervention is most critical. The use of biomaterials to develop diagnostics and theranostics, including nanoparticles and scaffolds for systemic or local applications, has significant promise to address these shortcomings and enable successful clinical translation. These developments in both modular and holistic design of diagnostic and theranostic biomaterials may improve patient treatments for myriad orthopaedic applications ranging from cancer to fractures to infection.

Factors Affecting Prognosis and Survival in Extremity Osteosarcoma

Background

Osteosarcoma is a malignant bone tumor affecting mainly children and young adults and commonly involves extremities. The aim of this study was to assess the patient-related, tumor-related, and treatment-related factors affecting the overall survival in patients with non-metastatic extremity osteosarcoma.

Methodology

A retrospective, single institutional study of 100 patients with non-metastatic extremity osteosarcoma was done between 2014 and 2019. Age, sex, histologic type, tumor site, use of preoperative chemotherapy and its duration, response to chemotherapy, type of surgery, presence of local recurrence, occurrence of lung metastasis, and survival data were recorded. Survival analysis was done using Kaplan-Meier method. p < 0.05 by log-rank test was considered statistically significant. Statistical data were analyzed using SPSS v.25(IBM).

Results

The median age of presentation was 18 years with male sex preponderance. The most common site of presentation was distal femur, and commonest histological variant was osteoblastic osteosarcoma. Incidence of local recurrence was 9%, and lung metastasis was identified in 12% on follow-up. The 5-year overall survival (OS) was 65.5%, and 5-year local recurrence-free survival was 57.6%. The 5-year OS in neoadjuvant chemotherapy group was 80% compared to 39.5% in upfront surgery group (p = 0.015). The 5-year OS in patients with tumor necrosis > 90% and < 90% was 93.2% and 71.2%, respectively (p = 0.038). The 5-year OS in patients without lung metastasis was 76%, whereas none who developed lung metastasis has survived 5 years (p < 0.001).

Conclusion

The use of neoadjuvant chemotherapy, good response to chemotherapy, and the absence of lung metastasis on follow-up can independently predict better overall survival.

Emergency Surgery in High Volume Osteosarcoma of Left Proximal Humerus Due to Vascular Compromise: A Case Report

BACKGROUND Osteosarcoma is the most common type of malignant bone tumor arising from mesenchymal stem cell. When occurring on the proximal humerus, it is associated with poor outcomes; there are numerous neurovascular structures around proximal humerus. Unfortunately, the degree of vascular involvement in osteosarcoma is rarely evaluated and reported. Thus, we would like to highlight our case. CASE REPORT We reported a case of left proximal humerus osteosarcoma causing dead limb in a 14-year-old boy. The dead limb progressed in the span of 3 weeks. An emergency forequarter amputation (FQA) was conducted to prevent further complications such as septicemia and mortality. Two months after the surgery, the patient had improved quality of life. One year after, the patient had no local recurrence. However, there was a lung metastasis detected 9 months after the surgery. The patient died 13 months after the surgery. CONCLUSIONS Osteosarcoma of the proximal humerus can potentially compromise vascular structures. Early diagnosis and treatment are mandatory to prevent such complications.

Ubiquitin-like protein FAT10 promotes osteosarcoma growth by modifying the ubiquitination and degradation of YAP1

Osteosarcoma is a common malignancy of the bone tissue. The rapid growth exhibited by this cancer is a primary challenge in its treatment. In many types of cancers, FAT10, a ubiquitin-like protein, is involved in several biological activities, especially cell proliferation. Herein, we demonstrate that FAT10 plays a vital role in tumorigenesis and is overexpressed in tumor tissues compared to its expression in adjacent normal tissues. Functional assays revealed that knockdown of FAT10 expression significantly repressed the proliferation of osteosarcoma in vitro and in vivo. Furthermore, our results indicate that FAT10 exhibits oncogenic functions by regulating the level of YAP1, a key protein of the Hippo/YAP signaling pathway, and a significant positive correlation exists between the levels of FAT10 and YAP1. Further analysis showed that FAT10-induced growth of osteosarcoma cells is dependent on YAP1. Mechanistically, FAT10 stabilizes YAP1 expression by regulating its ubiquitination and degradation. Taken together, our results link the two drivers of cell growth in osteosarcoma and reveal a novel pathway for FAT10 regulation. We provide new evidence for the biological and clinical significance of FAT10 as a potential biomarker for osteosarcoma.