Conditional survival and annual hazard of death in elderly patients with esophageal cancer receiving definitive chemoradiotherapy

Abstract Background: Definitive chemoradiotherapy is one of the primary treatment modalities for elderly patients with esophageal cancer (EC). It remains inadequately studied how prognosis evolves over time and how non-EC deaths affect overall survival (OS). We examined the conditional survival and annual hazard of death in elderly patients with EC after chemoradiotherapy.­ Methods: The data of patients with EC aged 65 or older registered in the Surveillance, Epidemiology, and End Results database during 2000–2019 were collected. Conditional survival was defined as the probability of survival given a specific time survived. Annual hazard of death was defined the yearly event rate. Results: Among 3739 patients, the 3-year conditional OS increased by 7%-10% annually. Non-EC causes accounted for 18.8% of deaths, with cardio-cerebrovascular diseases as the leading cause. Death hazard decreased from 40% to 10% in the first 6 years and then increased to 20% in the tenth year. The hazard of death from non-EC causes exceeded that from EC causes, starting 5 years after treatment. Older patients and those in early stages had higher risks of death from non-EC causes (HR = 1.36, 95% CI: 1.15-1.62, P < 0.001 and HR = 0.82, 95% CI: 0.68-0.98, P = 0.035, respectively). Tumor histology had no significant impact on non-EC death risk (HR = 1.17, 95% CI: 0.98-1.39, P = 0.081). Conclusions: For elderly patients with EC treated with chemoradiotherapy, survival probability increases with time. Stress on the management of comorbidities can extend the survival of older patients and those with early-stage disease.