Prognostic variables for conditional survival in patients with esophageal squamous cell carcinoma who underwent minimally invasive surgery

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) survival is mainly reported at the time of treatment. Conditional survival is another prognostic tool to evaluate ESCC patients who has survived more than one year since treatment. METHODS: We analyzed data from 705 ESCC patients who underwent minimally invasive surgery between 2013 and 2016. Using the Kaplan–Meier method, we computed a 5-year relative conditional survival. We also investigated the prognostic factors associated with survival using Cox proportional hazards models. RESULTS: Conditional survival improved over time for all cohorts of ESCC patients who survived a period after surgery. The greatest improve in conditional survival were observed in patients 2 years after surgery. In addition, the results of the Cox survival model from the time of surgery, T stage (p < 0.001), N stage (p < 0.001), and anastomotic leak (p = 0.022), were significantly associated with survival. However, the results of the Cox survival model from 2 years after surgery, N stage (p < 0.001), and anastomotic leak (p = 0.032) were significantly associated with survival. CONCLUSION: For ESCC patients who survived a period after surgery, the largest increases in conditional survival were observed in patients 2 years after surgery. We suggest that patients with anastomotic leakage and higher T and N stages should be strictly screened according to various time, and that conditional survival should be used as a powerful prognostic tool for ESCC patients.