Clinical Parameters Predicting Prognosis for Elderly Patients With Synchronous Oligometastatic Esophageal Squamous Cell Carcinoma

Abstract

To evaluate the potential survival benefits of adding radiotherapy to chemotherapy for elderly patients with synchronous oligometastatic esophageal squamous cell carcinoma (SOEC), to elucidate the factors influencing the prognosis of SOEC elderly patients, and to establish a nomogram for predicting the overall survival (OS) of elderly patients with SOEC.We retrospectively analyzed elderly patients with SOEC who received concurrent chemoradiotherapy (CCRT) and chemotherapy alone (CT) followed from January 2012 to December 2017. Each patient had ≤ 5 oligometastatic lesions, metastatic organs ≤ 3 and aged ≥ 60 years old were enrolled in this study. Patients were divided into CCRT and CT groups. The primary endpoints were progression-free survival (PFS) and OS, and the secondary endpoints were locoregional control and treatment-related toxicities. A nomogram based on prognostic factors associated with OS was established using R software on the basis of the Cox regression model.In total, 314 elderly patients with SOEC were analyzed with a median age of 66 (range, 60-81 years). Median follow up was 42.3 months (range, 3.2-77). There were 151 cases in the CCRT group and 163 cases in the CT group. ORR was 59.6% and 39.9% for the CCRT and CT groups, respectively (P = 0.000). Median PFS of the CCRT group and CT group was 10.0 and 7.2 months, respectively (P = 0.000), and median OS was 18.5 and 15.6 months, respectively (P = 0.000). In subgroup analysis, median PFS was 9.0 and 7.8 months for patients with 1-3 metastatic lesions and 4-5 metastatic lesions, respectively (P = 0.004), and median OS was 18.5 and 15.2 months, respectively (P = 0.000). The median OS of patients with 1 metastatic organ was 17.8 months, and that of patients with 2-3 metastatic organs was 15.6 months (P = 0.003). Cox multivariate regression analysis showed that the number of metastatic lesions (P = 0.012) and the treatment response (P = 0.000) were independent prognostic factors associated with OS. On the basis of the Cox model, the nomogram was established with a concordance index of 0.742 (95% CI: 0.711-0.773) after internal cross-validation. Calibration curves and DCA demonstrated that nomogram had a favorable predictive value for OS. The frequency of leukocytopenia (grade 3 or higher) was significantly higher in the CCRT group than in the CT group (P = 0.035). Other major toxicities of grade III or higher included radiation esophagitis (7.3%) and radiation pneumonitis (8.6%) for the CCRT group. No treatment-related deaths were observed throughout the study period.Compared with CT alone, CCRT can significantly improve the PFS and OS of elderly patients with SOEC. The PFS and OS of patients with 1-3 metastatic lesions were significantly better than that of patients with 4-5 metastatic lesions. Patients with 1 metastatic organ have longer FPS than patients with 2-3 metastatic organs. We developed a nomogram predicting 1-, 2-, and 3-year OS for elderly patients with SOEC.