Li Yifan, Zhang Xiaojuan
Second Department of General Surgery, Chinese Academy of Medical Sciences, Shanxi Province Cancer Hospital, Shanxi Hospital Affiliated to Cancer Hospital, Cancer Hospital Affiliated to Shanxi Medical University, Taiyuan, China.
Radiology Department, Chinese Academy of Medical Sciences, Shanxi Province Cancer Hospital, Shanxi Hospital Affiliated to Cancer Hospital, Cancer Hospital Affiliated to Shanxi Medical University, Taiyuan, China.
Front Surg. 2022 Aug 26;9:916483. doi: 10.3389/fsurg.2022.916483. eCollection 2022.
We sought to develop novel nomograms to accurately predict overall survival (OS) of chemotherapy cycles <9 and chemotherapy cycles ≥9 and construct risk stratification to differentiate low-risk and high-risk of two cohorts.
Patients who underwent curative-intent resection for gastric cancer between January 2002 and May 2020 at a single China institution were identified. Variables associated with OS were recorded and analyzed according to multivariable Cox models. Nomograms predicting 3- and 5-year OS were built according to variables resulting from multivariable Cox models. Discrimination ability was calculated using the Harrell's Concordance Index. The constructed nomogram was subjected to 1,000 resamples bootstrap for internal validation. Calibration curves for the new nomograms were used to test the consistency between the predicted and actual 3- and 5-year OS. Decision curve analysis (DCA) was performed to assess the clinical net benefit. The Concordance index (C-index) and time-dependent receiver operating characteristic (t-ROC) curves were used to evaluate and compare the discriminative abilities of the new nomograms. Finally, prognostic risk stratification of gastric cancer was conducted with X-tile software and nomograms converted into a risk-stratified prognosis model.
For the nomogram predict OS of chemotherapy cycles <9, C-index was 0.711 (95% CI, 0.663-0.760) in internal validation and 0.722 (95% CI, 0.662-0.783) in external validation, which was better than AJCC 8th edition TNM staging (internal validation: 0.627, 95% CI, 0.585-0.670) and (external validation: 0.595,95% CI, 0.543-0.648). The C-index of the nomogram for chemotherapy cycles ≥9 in internal validation was 0.755 (95% CI, 0.728-0.782) and 0.785 (95% CI, 0.747-0.823) in external validation, which was superior to the AJCC 8th edition TNM staging (internal validation: 0.712 95% CI, 0.688-0.737) and (external validation 0.734, 95% CI, 0.699-0.770).The calibration curves, t-ROC curves and DCA of the two nomogram models show that the recognition performance of the two nomogram models was outstanding. The statistical differences in the prognosis among the two risk stratification groups further showed that our model had an excellent risk stratification performance.
This is first reported risk stratification for chemotherapy cycles of gastric carcinoma. Our proposed nomograms can effectively evaluate postoperative prognosis of patients with different chemotherapy cycles of gastric carcinoma. Chemotherapy cycles ≥9 is therefore recommended for high-risk patients with chemotherapy cycles <9, but not for low-risk patients. Meanwhile, combination with multiple therapies are essential to high-risk patients with chemotherapy cycles ≥9 and unnecessary for low-risk patients.
我们试图开发新的列线图，以准确预测化疗周期<9次和化疗周期≥9次患者的总生存期（OS），并构建风险分层以区分两个队列的低风险和高风险。
确定2002年1月至2020年5月在中国一家机构接受胃癌根治性切除的患者。根据多变量Cox模型记录和分析与OS相关的变量。根据多变量Cox模型得出的变量构建预测3年和5年OS的列线图。使用Harrell一致性指数计算辨别能力。对构建的列线图进行1000次重采样自举以进行内部验证。新列线图的校准曲线用于检验预测的和实际的3年和5年OS之间的一致性。进行决策曲线分析（DCA）以评估临床净效益。一致性指数（C指数）和时间依赖性受试者工作特征（t-ROC）曲线用于评估和比较新列线图的辨别能力。最后，使用X-tile软件对胃癌进行预后风险分层，并将列线图转换为风险分层预后模型。
对于预测化疗周期<9次患者OS的列线图，内部验证中C指数为0.711（95%CI，0.663-0.760），外部验证中为0.722（95%CI，0.662-0.783），优于美国癌症联合委员会（AJCC）第8版TNM分期（内部验证：0.627，95%CI，0.585-0.670）和（外部验证：0.595，95%CI，0.543-0.648）。化疗周期≥9次患者列线图在内部验证中的C指数为0.755（95%CI，0.728-0.782），外部验证中为0.785（95%CI，0.747-0.823），优于AJCC第8版TNM分期（内部验证：0.712，95%CI，0.688-0.737）和（外部验证：0.734，95%CI，0.699-0.770）。两个列线图模型的校准曲线、t-ROC曲线和DCA表明，两个列线图模型的识别性能出色。两个风险分层组之间预后的统计学差异进一步表明，我们的模型具有出色的风险分层性能。
这是首次报道的胃癌化疗周期风险分层。我们提出的列线图可以有效评估不同化疗周期胃癌患者的术后预后。因此，对于化疗周期<9次的高危患者，建议化疗周期≥9次，但低风险患者不建议。同时，对于化疗周期≥9次的高危患者，联合多种治疗至关重要，而低风险患者则不必要。
