Department of Gastroenterology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
Department of Clinical Research, The First Affiliated Hospital of Jinan University, Guangzhou, 510630, Guangdong Province, China.
BMC Gastroenterol. 2022 Feb 10;22(1):57. doi: 10.1186/s12876-022-02131-1.
Rectal adenocarcinoma is one of major public health problems, severely threatening people's health and life. Cox proportional hazard models have been applied in previous studies widely to analyze survival data. However, such models ignore competing risks and treat them as censored, resulting in excessive statistical errors. Therefore, a competing-risk model was applied with the aim of decreasing risk of bias and thereby obtaining more-accurate results and establishing a competing-risk nomogram for better guiding clinical practice.
A total of 22,879 rectal adenocarcinoma cases who underwent primary-site surgical resection were collected from the SEER (Surveillance, Epidemiology, and End Results) database. Death due to rectal adenocarcinoma (DRA) and death due to other causes (DOC) were two competing endpoint events in the competing-risk regression analysis. The cumulative incidence function for DRA and DOC at each time point was calculated. Gray's test was applied in the univariate analysis and Gray's proportional subdistribution hazard model was adopted in the multivariable analysis to recognize significant differences among groups and obtain significant factors that could affect patients' prognosis. Next, A competing-risk nomogram was established predicting the cause-specific outcome of rectal adenocarcinoma cases. Finally, we plotted calibration curve and calculated concordance indexes (c-index) to evaluate the model performance.
22,879 patients were included finally. The results showed that age, race, marital status, chemotherapy, AJCC stage, tumor size, and number of metastasis lymph nodes were significant prognostic factors for postoperative rectal adenocarcinoma patients. We further successfully constructed a competing-risk nomogram to predict the 1-year, 3-year, and 5-year cause-specific mortality of rectal adenocarcinoma patients. The calibration curve and C-index indicated that the competing-risk nomogram model had satisfactory prognostic ability.
Competing-risk analysis could help us obtain more-accurate results for rectal adenocarcinoma patients who had undergone surgery, which could definitely help clinicians obtain accurate prediction of the prognosis of patients and make better clinical decisions.
直肠腺癌是重大公共卫生问题之一，严重威胁着人们的健康和生命。在之前的研究中，广泛应用 Cox 比例风险模型来分析生存数据。然而，这些模型忽略了竞争风险，并将其视为删失数据，导致了过多的统计误差。因此，应用竞争风险模型的目的是降低偏倚风险，从而获得更准确的结果，并建立竞争风险列线图，以更好地指导临床实践。
从 SEER（监测、流行病学和最终结果）数据库中收集了 22879 例接受原发部位手术切除的直肠腺癌病例。直肠腺癌死亡（DRA）和其他原因死亡（DOC）是竞争风险回归分析中的两个竞争终点事件。计算每个时间点 DRA 和 DOC 的累积发生率函数。在单变量分析中应用 Gray 检验，在多变量分析中应用 Gray 比例亚分布风险模型，以识别组间的显著差异，并获得影响患者预后的显著因素。然后，建立预测直肠腺癌患者特定原因结局的竞争风险列线图。最后，我们绘制校准曲线并计算一致性指数（c-index）来评估模型性能。
最终纳入 22879 例患者。结果表明，年龄、种族、婚姻状况、化疗、AJCC 分期、肿瘤大小和转移淋巴结数量是术后直肠腺癌患者的显著预后因素。我们进一步成功构建了一个竞争风险列线图，以预测直肠腺癌患者 1 年、3 年和 5 年的特定原因死亡率。校准曲线和 C-index 表明竞争风险列线图模型具有良好的预后能力。
竞争风险分析可以帮助我们获得更准确的结果，从而帮助临床医生对患者的预后做出准确预测，并做出更好的临床决策。
