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

Abstract

Background: Definitive chemoradiotherapy is one of the primary treatment modalities for older patients with esophageal cancer (EC). However, the evolution of prognosis over time and the factors affected non-EC deaths remain inadequately studied. We examined the conditional survival and annual hazard of death in older patients with EC after chemoradiotherapy.

Methods: We collected data from patients aged 65 or older with EC registered in the Surveillance, Epidemiology, and End Results database during 2000-2019. Conditional survival was defined as the probability of survival given a specific time survived. Annual hazard of death was defined the yearly event rate. Restricted cubic spline (RCS) analysis identified the association of age at diagnosis with mortality.

Results: Among 3739 patients, the 3-year conditional overall survival increased annually by 7-10%. Non-EC causes accounted for 18.8% of deaths, predominantly due to cardio-cerebrovascular diseases. The hazard of death decreased from 40 to 10% in the first 6 years and then gradually increased to 20% in the tenth year. Non-EC causes surpassed EC causes in hazard starting 5 years post-treatment. RCS indicated a consistent increase in death hazard with advancing age, following a linear relationship. The overall cohort was divided into two groups: 65-74 and ≥ 75 years old, with the ≥ 75-year-old group showing poorer survival and earlier onset of non-EC deaths (HR = 1.36, 95% CI: 1.15-1.62, P < 0.001). Patients with early-stage disease (I-II) had higher risks of death from non-EC causes (HR = 0.82, 95% CI: 0.68-0.98, P = 0.035). Tumor histology had no significant impact on non-EC death risk (HR = 1.17, 95% CI: 0.98-1.39, P = 0.081).

Conclusions: Survival probability increases with time for older patients with EC treated with chemoradiotherapy. Clinicians and patients should prioritize managing and preventing age-related comorbidities, especially in older cohorts and those with early-stage disease.

Keywords: Conditional survival; Death hazard; Esophageal cancer; Older.

Fig. 1

Diagram showing study sample selection process. SEER, Surveillance, Epidemiology, and End Results

Fig. 2

(A) Conditional overall survival (OS) curves as a function of the number of years survived since treatment. (B) Conditional cancer-specific survival (CSS) curves as a function of the number of years of cancer-specific survival since treatment. The colors of the lines are assigned in the order of years survived or cancer-specific survival since treatment, from years 0 to 5. (C) Three-year conditional survival probability as a function of the number of years survived or cancer-specific survival since treatment. (D) Smoothed hazard plots for annual rates of death from all causes, death from EC, and death from non-EC causes by time after treatment. OS, overall survival; CSS, cancer-specific survival; EC, esophageal cancer

Fig. 3

The restricted cubic spline plot for the association of age at diagnosis and hazard of death from all causes (A), EC cause (B), and non-EC causes (C). EC, esophageal cancer

Fig. 4

Smoothed hazard plots for annual rate of death from all causes, death from EC, and death from non-EC causes by time after treatment, stratified by the age (A- B), histology (C- D), and stage (E- F). EC, esophageal cancer