Bo Li

Background: Solitary spinal metastasis (SM) is one of the indications for total en bloc spondylectomy (TES). Conventional TES carries the risk of damage to the great vessels anterior to the vertebral column, mainly because of a lack of visualization of the anterior structures. In this study, we devised a modified standard TES technique to achieve direct visualization in a 1-stage posterior approach. Methods: Included in this study were patients ≥18 years old with solitary thoracic or lumbar SM who underwent the modified standard TES at our institution between January 2017 and October 2022. Patient data were retrospectively sourced from medical records, and patients had a minimum of 3 months of postoperative follow-up. Results: This study involved 71 East Asian patients (median age, 57 years; 34 males), comprising 38 patients with thoracic SM and 33 with lumbar SM. Lung cancer was the most common tumor histology. Fourteen patients (19.7%) experienced intraoperative complications; pleural rupture was the predominant complication, and there were no cases of injury to the spinal cord or great vessels. The median operative time was 305 minutes (range, 203 to 660 minutes). The median intraoperative blood loss was 1,000 mL (range, 400 to 4,000 mL). The median perioperative blood transfusion was 4 units (range, 0 to 12 units), and the median hospitalization duration was 17 days (range, 14 to 29 days). Additionally, 27 patients (38.0%) had acute (perioperative) complications. Seven patients were lost to follow-up. Significant clinical improvement was achieved 3 months postoperatively. Postoperative early and late complications were observed in 5 patients. Of the 64 patients with completed follow-up, 47 (73.4%) had negative surgical margins, and none received postoperative radiation therapy. Revision surgery for local tumor recurrence was performed in 4.7% of patients. The median follow-up was 31.5 months (range, 3 to 81 months). Conclusions: Our modified standard TES was demonstrated to be a safe and effective surgical technique for solitary thoracolumbar SM. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The tumor microenvironment (TME) acts as a crucial role in the occurrence and development of osteosarcoma (OS). Despite this, the mechanism controlling the components of immunity and stroma in the tumor microenvironment remains a mystery. To conduct this study, we download and collate transcriptome data from the TARGET database, whose full name is Therapeutically Applicable Research to Generate Effective Treatments, as well as available clinical information of OS. The CIBERSORT and ESTIMATE methodology are used to acquire the proportions of components of immunity and stroma and tumor-infiltrating immune cells (TICs). Protein-protein interaction (PPI) networks and Cox regression analysis are used to select differentially expressed genes (DEGs). A prognostic biomarker is determined by intersecting univariate COX and PPI results, which lead to the finding of Triggering receptor expressed on myeloid cells-2 (TREM2). Based on the next analysis, TREM2 expression is positively correlated with OS survival time. Immune function-related genes have enrichment in the group with high expression of TREM2, according to gene set enrichment analysis (GSEA). The percentage of TICs by CIBERSORT methodology revealed that the expression of TREM2 is positively associated with follicular helper T cells, CD8-positive T cells, and M2 macrophages and negatively correlated with plasma cells, M0 macrophages, and naive CD4-positive T cells. All results suggest a possible integral role of TREM2 in the immune-related events of TME. Therefore, TREM2 may be a potential indicator of remodeling of TME in osteosarcoma, which is useful and helpful in predicting the clinical prognostic outcome of OS patients and provide a unique perspective for immunotherapy for OS.