Zhao Shengguang, Qi Weixiang, Chen Jiayi
Department of Radiation Oncology, Rui Jin Hospital Affiliated Medicine School of Shanghai Jiao Tong University, Shanghai 200025, P.R. China.
Oncol Lett. 2020 May;19(5):3513-3521. doi: 10.3892/ol.2020.11448. Epub 2020 Mar 6.
The present study aimed to investigate the probability of cancer-associated mortality of patients with esophageal cancer undergoing intensity-modulated radiation therapy (IMRT), and to establish a competing risk nomogram to predict the esophageal cancer-specific survival (EC-SS) of these patients. A total of 213 patients with EC who underwent IMRT between January 2014 and May 2017 were selected to establish nomograms according to Fine and Gray's competing risk analysis. Predictive accuracy and discriminative ability of the model were determined using the concordance index (C-index), calibration curves and the area under receiver operating characteristic curves. Decision tree analysis was also constructed for patient grouping. With a median follow-up of 19 months (range, 3-50), the 2-year EC-specific mortality (EC-SM) and the non-esophageal cancer specific mortality (NEC-SM) of the cohort were 35.4 and 3.51%, respectively. Furthermore, an elevated 2-year EC-SM was observed in patients with tumor length ≥4.5 cm compared with patients with tumor length <4.5 cm (45.8% vs. 21.4%; P<0.001), patients with non-squamous cell carcinoma compared with patients with squamous cell carcinoma (49.9 vs. 33.7%; P=0.025) and patients with N3 stage (43.2%; P=0.005). The 2-year NEC-SM of patients with tumor length ≥4.5 cm was 6% vs. 0% in patients with tumor length <4.5 cm (P=0.016). Three independent risk factors for survival, including tumor length, histological type and N stage, were integrated to build competing nomograms for the EC-SS model (C-index=0.72; 95% confidence interval, 0.66-0.77). In addition, the nomograms displayed better discrimination power than the 7th edition of the Tumor-Node-Metastasis staging system for predicting EC-SS (area under the curve=0.707 vs. 0.634). Furthermore, the results from the classification tree analysis demonstrated that N stage was the initial node and that primary tumor length was a determinant for EC-SM in these patients. In conclusion, NEC-SM represented a competing event for patients with EC with a tumor length ≥4.5 cm. The competing risk nomograms may therefore be considered as convenient individualized predictive tools for cancer-specific survival in patients with EC undergoing IMRT treatment.
本研究旨在调查接受调强放射治疗（IMRT）的食管癌患者发生癌症相关死亡的概率，并建立一个竞争风险列线图以预测这些患者的食管癌特异性生存（EC-SS）情况。选取2014年1月至2017年5月期间接受IMRT的213例EC患者，根据Fine和Gray的竞争风险分析建立列线图。使用一致性指数（C指数）、校准曲线和受试者操作特征曲线下面积来确定模型的预测准确性和判别能力。还构建了决策树分析进行患者分组。中位随访时间为19个月（范围3-50个月），该队列的2年EC特异性死亡率（EC-SM）和非食管癌特异性死亡率（NEC-SM）分别为35.4%和3.51%。此外，与肿瘤长度<4.5 cm的患者相比，肿瘤长度≥4.5 cm的患者2年EC-SM升高（45.8%对21.4%；P<0.001），非鳞状细胞癌患者与鳞状细胞癌患者相比（49.9%对33.7%；P=0.025）以及N3期患者（分别为43.2%；P=0.005）。肿瘤长度≥4.5 cm的患者2年NEC-SM为6%，而肿瘤长度<4.5 cm的患者为0%（P=0.016）。整合了包括肿瘤长度、组织学类型和N分期在内的三个独立生存危险因素，构建了EC-SS模型的竞争风险列线图（C指数=0.72；95%置信区间，0.66-0.77）。此外，在预测EC-SS方面，列线图显示出比第7版肿瘤-淋巴结-转移分期系统更好的判别能力（曲线下面积=0.707对0.634）。此外，分类树分析结果表明，N分期是初始节点，原发肿瘤长度是这些患者EC-SM的决定因素。总之，NEC-SM是肿瘤长度≥4.5 cm的EC患者的一个竞争事件。因此，竞争风险列线图可被视为接受IMRT治疗的EC患者癌症特异性生存的便捷个体化预测工具。
