BACKGROUND Surgical treatment for hepatocellular carcinoma (HCC) is advancing, but a robust prediction model for survival after resection is not available. The aim of this study was to propose a prognostic grading system for resection of HCC. METHODS This was a retrospective, multicentre study of patients who underwent first resection of HCC with curative intent between 2000 and 2007. Patients were divided randomly by a cross-validation method into training and validation sets. Prognostic factors were identified using a Cox proportional hazards model. The predictive model was built by decision-tree analysis to define the resection grades, and subsequently validated. RESULTS A total of 16 931 patients from 795 hospitals were included. In the training set (8465 patients), four surgical grades were classified based on prognosis: grade A1 (1236 patients, 14.6 per cent; single tumour 3 cm or smaller and anatomical R0 resection); grade A2 (3614, 42.7 per cent; single tumour larger than 3 cm, or non-anatomical R0 resection); grade B (2277, 26.9 per cent; multiple tumours, or vascular invasion, and R0 resection); and grade C (1338, 15.8 per cent; multiple tumours with vascular invasion and R0 resection, or R1 resection). Five-year survival rates were 73.9 per cent (hazard ratio (HR) 1.00), 64.7 per cent (HR 1.51, 95 per cent c.i. 1.29 to 1.78), 50.6 per cent (HR 2.53, 2.15 to 2.98), and 34.8 per cent (HR 4.60, 3.90 to 5.42) for grades A1, A2, B, and C respectively. In the validation set (8466 patients), the grades had equivalent reproducibility for both overall and recurrence-free survival (all P < 0.001). CONCLUSION This grade is used to predict prognosis of patients undergoing resection of HCC.

中文翻译：

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切除肝细胞癌的预后等级：多中心回顾性研究。

背景技术针对肝细胞癌（HCC）的外科治疗正在不断发展，但是尚无用于切除后生存的可靠预测模型。这项研究的目的是为肝癌切除术提出一个预后分级系统。方法这是一项回顾性，多中心研究，研究对象是2000年至2007年间首次行根治性肝癌切除术的患者。采用交叉验证方法将患者随机分为训练和验证集。使用Cox比例风险模型确定预后因素。通过决策树分析建立预测模型以定义切除级别，并随后进行验证。结果包括来自795家医院的16 931名患者。在训练集中（8465位患者）中，根据预后分类了四个手术等级：A1级（1236例患者，占14.6％；单个肿瘤3厘米或更小，且解剖R0切除）；A2级（3614，占42.7％；单个肿瘤大于3厘米，或非解剖性R0切除）；B级（2277％，占26.9％；有多个肿瘤或血管侵犯，并进行R0切除）；C级（1338，占15.8％；具有血管侵犯和R0切除或R1切除的多个肿瘤）。五年生存率分别为73.9％（危险比（HR）1.00），64.7％（HR 1.51、95％ci 1.29至1.78），50.6％（HR 2.53、2.15至2.98）和34.8％ （HR 4.60、3.90至5.42）分别针对A1，A2，B和C级。在验证集中（8466名患者），这些评分对于总体生存期和无复发生存期具有同等的可重复性（所有P <0.001）。