We added a comment to the the article by Kim et al.. We first described how the hazard function and commonly used survival function act complementary, although these two functions are mathematically equivalent. Then, we pointed out two notable findings of the present article: 1) a recurrence by metastasis is presumed to occurred constantly at an annualized incidence of 4%-10% until 6 postoperative years; and 2) the annualized recurrence rates between the 5th and 10th postoperative years were between 3%-10% in cirrhotic patients and this figure was comparable to or even lower than the reported annual incidence of HCC in cirrhotic patients (up to 8%). We also pointed out three issues to be paid attention for: 1) the authors amalgamated patients with HBV- and HCV-related HCC together when calculating the hazard function, although the background liver of HCV-related HCC is hypothesized to have a higher carcinogenetic activity than that of HBV-related HCC, at least during the era before the advent of direct-acting antivirals; 2) the authors would have obtained interesting results had they evaluated the risk factors for late-phase recurrence exclusively in patients with HBV infection, including HBV-specific covariates into the analysis; and 3) many investigators may confuse a pathogenic factor with its surrogate marker when interpreting the significance of fibrosis in studies investigating risk factors leading to HCC development.


中文翻译：

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信函 RE：切除后特定时期的复发风险作为肝细胞癌患者监测策略的框架：一项多中心结果研究

我们在 Kim 等人的文章中添加了评论。我们首先描述了危险函数和常用的生存函数如何互补，尽管这两个函数在数学上是等价的。然后，我们指出了本文的两个值得注意的发现：1）假定转移性复发在术后 6 年内以每年 4%-10% 的年发生率持续发生；2）肝硬化患者术后第 5 年和第 10 年的年化复发率在 3%-10% 之间，这一数字与肝硬化患者报告的 HCC 年发病率（高达 8%）相当甚至更低。我们还指出了三个需要注意的问题：1）作者在计算风险函数时将HBV和HCV相关的HCC患者合并在一起，尽管假设 HCV 相关 HCC 的背景肝脏比 HBV 相关 HCC 具有更高的致癌活性，至少在直接抗病毒药物出现之前的时代是这样；2) 如果作者仅在 HBV 感染患者中评估晚期复发的危险因素，包括分析中的 HBV 特异性协变量，他们将会获得有趣的结果；3) 许多研究人员在研究导致 HCC 发展的危险因素的研究中解释纤维化的重要性时，可能会将致病因素与其替代标志物混淆。2) 如果作者仅在 HBV 感染患者中评估晚期复发的危险因素，包括分析中的 HBV 特异性协变量，他们将会获得有趣的结果；3) 许多研究人员在研究导致 HCC 发展的危险因素的研究中解释纤维化的重要性时，可能会将致病因素与其替代标志物混淆。2) 如果作者仅在 HBV 感染患者中评估晚期复发的危险因素，包括分析中的 HBV 特异性协变量，他们将会获得有趣的结果；3) 许多研究人员在研究导致 HCC 发展的危险因素的研究中解释纤维化的重要性时，可能会将致病因素与其替代标志物混淆。