Table 1_Development and validation of a predictive score for chemoresistance in high-grade osteosarcoma at baseline.docx

ObjectiveHistological tumor necrosis is the current indicator for the response of osteosarcoma after neoadjuvant chemotherapy. Chemoresistant tumors require close monitoring and adjustment of treatment. We aimed to develop a prediction score for chemoresistance in newly diagnosed osteosarcoma patients underwent neoadjuvant chemotherapy.
Materials and methodsData from a registry-based cohort of high-grade osteosarcoma patients treated with neoadjuvant chemotherapy between January 2008 and October 2023 were used. Histological necrosis from surgical specimens was the reference standard. Clinical and MRI parameters at baseline were derived by risk regression analysis.
ResultsFrom 139 patients, 93 (66.91%) were classified as chemoresistant (histological necrosis <90%). The model included four predictors: age >40 years, initial metastasis, tumor volume (≤150 ml, > 150–400, or > 400 ml), and pre-chemotherapy tumor necrosis >50%. The AuROC of the model was 0.76 (95% CI 0.68–0.85) and well-calibrated. Internal validation using a bootstrap technique showed consistent AuROC results. The prediction score ranged from 0 to 8, with a score of 0–2 indicating low probability (positive LHR = 0.45) and a score of 3–8 indicating high probability (positive LHR = 2.56) of chemoresistance.
ConclusionHigh-grade osteosarcoma patients with a prediction score of 3–8 have a high probability of chemoresistance. This score could be used for risk communication and tailoring management at diagnosis.

研究背景与目的：组织学肿瘤坏死是目前评估骨肉瘤患者新辅助化疗后疗效的核心指标。化疗耐药性肿瘤需密切监测并调整治疗方案。本研究旨在为初诊并接受新辅助化疗的骨肉瘤患者构建化疗耐药预测评分模型。
材料与方法：本研究纳入2008年1月至2023年10月期间接受新辅助化疗的高级别骨肉瘤患者的登记队列临床数据。以手术标本的组织学坏死率作为疗效评价的金标准。通过风险回归分析提取基线临床及磁共振成像（Magnetic Resonance Imaging, MRI）参数。
研究结果：本队列共纳入139例患者，其中93例（66.91%）被判定为化疗耐药（组织学坏死率<90%）。最终模型纳入4项预测因素：年龄＞40岁、初始转移状态、肿瘤体积（≤150ml、150~400ml或＞400ml）以及化疗前肿瘤坏死率＞50%。该模型的受试者工作特征曲线下面积（Area Under the Receiver Operating Characteristic Curve, AuROC）为0.76（95%置信区间[CI] 0.68~0.85），且校准度良好。采用自举法进行内部验证，结果显示AuROC保持稳定。本研究构建的预测评分范围为0~8分：0~2分为低化疗耐药概率组（阳性似然比[LHR]=0.45），3~8分为高化疗耐药概率组（阳性似然比[LHR]=2.56）。
研究结论：预测评分3~8分的高级别骨肉瘤患者具有较高的化疗耐药风险。该评分可用于初诊时的风险沟通，并指导个体化诊疗方案的制定。