[Malignant round cell tumors : The Ewing sarcoma and beyond]

A Visualized Dynamic Prediction Model for Lymphatic Metastasis in Ewing's Sarcoma for Smart Medical Services

Background

This study aims to predict the lymphatic metastasis in Ewing's sarcoma (ES) patients by nomogram. The risk of lymphatic metastasis in patients with ES was predicted by the built model, which provided guidance for the clinical diagnosis and treatment planning.

Methods

A total of 929 patients diagnosed with ES were enrolled from the year of 2010 to 2016 in the Surveillance, Epidemiology, and End Results (SEER) database. The nomogram was established to determine predictive factors of lymphatic metastasis according to univariate and multivariate logistic regression analysis. The validation of the model performed using multicenter data (n = 51). Receiver operating characteristics (ROC) curves and calibration plots were used to evaluate the prediction accuracy of the nomogram. Decision curve analysis (DCA) was implemented to illustrate the practicability of the nomogram clinical application. Based on the nomogram, we established a web calculator to visualize the risk of lymphatic metastases. We further plotted Kaplan-Meier overall survival (OS) curves to compare the survival time of patients with and without lymphatic metastasis.

Results

In this study, the nomogram was established based on six significant factors (survival time, race, T stage, M stage, surgery, and lung metastasis), which were identified for lymphatic metastasis in ES patients. The model showed significant diagnostic accuracy with the value of the area under the curve (AUC) was 0.743 (95%CI: 0.714–0.771) for SEER internal validation and 0.763 (95%CI: 0.623–0.871) for multicenter data external validation. The calibration plot and DCA indicated that the model had vital clinical application value.

Conclusion

In this study, we constructed and developed a nomogram with risk factors to predict lymphatic metastasis in ES patients and validated accuracy of itself. We found T stage (Tx OR = 2.540, 95%CI = 1.433–4.503, P < 0.01), M stage (M1, OR = 2.061, 95%CI = 1.189–3.573, P < 0.05) and survival time (OR = 0.982, 95%CI = 0.972–0.992, P < 0.001) were important independent factors for lymphatic metastasis in ES patients. Furthermore, survival time in patients with lymphatic metastasis or unclear situation (P < 0.0001) was significantly lower. It can help clinicians make better decisions to provide more accurate prognosis and treatment for ES patients.

Applications of CRISPR/Cas9 in the research of malignant musculoskeletal tumors

Background

Malignant tumors of the musculoskeletal system, especially osteosarcoma, Ewing sarcoma and rhabdomyosarcoma, pose a major threat to the lives and health of adolescents and children. Current treatments for musculoskeletal tumors mainly include surgery, chemotherapy, and radiotherapy. The problems of chemotherapy resistance, poor long-term outcome of radiotherapy, and the inherent toxicity and side effects of chemical drugs make it extremely urgent to seek new treatment strategies.

Main text

As a potent gene editing tool, the rapid development of CRISPR/Cas9 technology in recent years has prompted scientists to apply it to the study of musculoskeletal tumors. This review summarizes the application of CRISPR/Cas9 technology for the treatment of malignant musculoskeletal tumors, focusing on its essential role in the field of basic research.

Conclusion

CRISPR, has demonstrated strong efficacy in targeting tumor-related genes, and its future application in the clinical treatment of musculoskeletal tumors is promising.

Frequency of Translocation t(11;22)(q24;q12) Using Fluorescence In Situ Hybridization (FISH) in Histologically and Immunohistochemically Diagnosed Cases of Ewing's Sarcoma

Introduction

Ewing sarcoma (ES) family of tumors is one of the most common groups of malignancies arising in children, adolescents, and young adults. Although characteristic histology with immunohistochemical expression of CD99 and FLI1 after exclusion of other small round blue cell tumors is considered diagnostic of ES, frequency of typical ES translocation, i.e., t(11;22)(q24;q12) is not known in our population. Therefore, in this study, we aimed to evaluate the frequency of this translocation in histologically and immunohistochemically diagnosed cases of ES along with its association with other pathological parameters.

Methods

A total of 43 morphologically and immunohistochemically diagnosed cases of ES were included in the study. Fluorescence in situ hybridization (FISH) was performed on representative paraffin blocks to identify t(11;22)(q24;q12) translocation. Association with various clinicopathological characteristics was determined.

Results

Mean age of the patients was 18.23±9.57 years. Bone was the most commonly involved site (22; 51.2%) followed by soft tissue (17; 39.5%) and parenchymal organs (4; 9.3%). A total of 88.4% of cases were found to be FISH-positive for t(11;22)(q24;q12). No significant association of translocation positive cases was noted with tumor size or disease-free survival. Similarly, no significant association of tumor size with disease-free survival was found.

Conclusions

A significant proportion of cases of histologically diagnosed cases of ES exhibited characteristic t(11;22)(q24;q12). This signifies that histology along with immunohistochemistry is reliable for the diagnosis of this tumor; however, in difficult cases, FISH can be performed to detect characteristic translocation. Moreover, we did not find tumor size to be a significant prognostic indicator of survival in ES.