A comparative study of elective nodal irradiation and involved field irradiation in elderly patients with advanced esophageal cancer

Objective: This comparative study aimed to explore the feasibility of involved field irradiation (IFI) in the radiotherapy of elderly patients with advanced esophageal cancer, compared with elective nodal irradiation (ENI).Methods: A total of 245 elderly patients (age >= 70 years) with advanced esophageal cancer, who received radiotherapy in our department from January 2014 to December 2020, were divided into the ENI group (n=111) and the IFI group (n=134). Clinical efficacy, toxicities, survival rates, treatment failures, and multifactorial survival analyses were conducted for both groups.Results: The ENI group and the IFI group showed no significant differences in terms of short-term efficacy (91.9% vs 91.0%, P=0.814), 1-year overall survival (OS) (81.1% vs 74.6%, P=0.228), 2-year OS (22.5% vs 25.4%, P= 0.603), 1-year progression-free survival (PFS) (56.8% vs 51.5%, P= 0.198), 2-year PFS (8.1% vs 9.0%, P=0.814), regional failures (38.7% vs 31.3%, P=0.226), and distant metastasis (21.6% vs 14.9%, P=0.174). The median overall survival (OS) was 19 months in the ENI group and 18 months in the IFI group (Log-rank chi(2) = 0.012, P=0.913). The median progression-free survival (PFS) was 13 months in the ENI group and 11 months in the IFI group (Log-rank chi(2) = 1.834, P=0.176). There were no significant statistical differences in both OS and PFS (P>0.05). The incidence of grade >= 3 radiation pneumonia and grade >= 3 radiation esophagitis in the IFI group was 8.2% and 11.2%, respectively, which were significantly lower than those in the ENI group (17.1%, P=0.034; 21.6%, P=0.026). Univariate analysis revealed that age, gender, T stage, N stage, and synchronous chemotherapy were factors affecting prognosis. Multivariate analysis showed that age, gender, T stage, and synchronous chemotherapy were independent prognostic factors, with hazard ratios of 1.227, 1.466, 2.441, and 2.714, and P values of <0.001, 0.006, <0.001, and<0.001, respectively.Conclusion: IFI is a suitable choice for elderly patients with advanced esophageal cancer, as it yields similar efficacy to ENI while reducing toxicities. Age, gender, T stage, and synchronous chemotherapy are independent prognostic factors for elderly patients with esophageal cancer.