Clinical features and prognostic factors for spinal metastasis from sarcomatoid carcinoma: identifying candidates suitable for surgical intervention

BACKGROUND: Sarcomatoid carcinoma (SC) frequently metastasizes, with bone being the most common site, and the spine is often affected. However, dedicated studies on spinal metastasis from SC remain scarce, complicating the determination of appropriate surgical intervention strategies. METHODS: We retrospectively analyzed 25 patients with spinal metastasis from SC. Clinical, radiological, pathological, treatment, and survival data were comprehensively evaluated. Prognostic factors were assessed using Kaplan-Meier analysis and Cox regression models, leading to the development of a simplified prognostic stratification system. RESULTS: Among the 25 patients, 7 had lung-derived SC and 12 had SC of unknown primary origin. No significant prognostic differences were observed across different primary sites. Notably, 19 patients initially presented with symptoms attributable to spinal metastasis. SC spinal metastases lacked distinct characteristic imaging features. Among treatment modalities, only targeted therapy and immunotherapy demonstrated a trend toward improved survival outcomes. Multivariate analysis identified the number of metastatic lesions, D-dimer level, and neutrophil-to-lymphocyte ratio (NLR) as independent prognostic factors for overall survival (OS). A nomogram constructed from these three factors reliably predicted the 1-year survival rate. We further established a simplified prognostic stratification system that may assist in guiding surgical decision-making. CONCLUSION: Targeted therapy and immunotherapy may confer survival benefits to patients with spinal metastasis from SC. Our prognostic stratification system, based on the number of metastatic lesions, D-dimer level, and NLR, enables estimation of OS and may facilitate risk-adapted surgical stratification, which may serve as a supplement to the present clinical frameworks.