Medicine (Baltimore). 2025 Oct 24. 104(43): e44992
BACKGROUND: The spinal instability neoplastic score (SINS) provides a standardized assessment of spinal stability in patients with metastatic spine disease. Although intended to assist clinical decision-making, the relationships between SINS and patient-centered measures, such as pain intensity, functional status, and health-related quality of life (HRQoL), remain undefined.
METHODS: This systematic review followed PRISMA guidelines. A comprehensive literature search was performed across PubMed, Scopus, Embase, and Web of Science databases using keywords related to SINS and spinal metastases. Studies assessing the relationships between SINS and pain intensity scores, functional status, and HRQoL were included. Data on study characteristics, type of interventions, and patient-centered measures were extracted. Risk of bias was assessed using the Newcastle-Ottawa Scale. A meta-analysis was not feasible due to significant treatment, outcome, and population heterogeneity.
RESULTS: Thirteen studies (n = 1823; mean age 63.0 ± 12.5 years) were included. Five of six studies reported a significant association between higher baseline SINS scores and pain intensity, most commonly using the Visual Analog Scale and Numeric Rating, while 1 of 2 studies identified a predictive value of SINS for posttreatment pain. Nine studies evaluated peri-interventional functional status using 6 different tools; significant correlations with baseline SINS were identified for MD Anderson Symptom Inventory and Spine Oncology Study Group Outcomes Questionnaire 2.0, while no relationships were identified for the Barthel Index, Eastern Cooperative Oncology Group score, or Frankel scale. Further, stable postradiotherapy SINS was associated a higher baseline Karnofsky Performance Status (KPS). Three studies assessed HRQoL using either the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30, the 36-Item Short Form Survey, or the EuroQol Five-Dimension Scale; 2 of these studies reported that higher SINS values were associated with lower baseline physical functioning. Of 13 studies, 12 were of moderate methodological quality.
CONCLUSIONS: SINS demonstrated correlations with peri-interventional pain intensity, functional status, and HRQoL. Pretreatment correlations were generally more consistent. However, in radiotherapy-treated cohorts, stable posttreatment SINS was associated with higher baseline KPS, suggesting a potential predictive relationship between these measures.
Keywords: functional status; pain outcomes; patient-reported outcomes; quality of life; spinal instability; spinal metastasis