Conditional survival reflects dynamic prognosis updated to the current status and is a more relevant indicator for current healthcare and life decisions.
This study included 1,883 patients who underwent complete resection for esophageal squamous cell carcinoma at a tertiary cancer center from 1994 to 2016. We calculated 5-year (5Y) conditional overall survival (COS), conditional recurrence-free survival (CRFS), and conditional relative survival (CRS) estimates from diagnosis to 5 years of survival.
The 5Y COS, CRFS, and CRS increased from 63.7%, 65.2%, and 70.2% at diagnosis to 75.8%, 91.9%, and 86.4 at 5 years after diagnosis, respectively. While there were large differences with different stages (stage I, II, III) at diagnosis (81.2%, 64.9%, and 37.3% for COS; 85.1, 65.1%, and 67.9% for CRFS; 89.2%, 72.1%, and 41.1% for CRS), the gap decreased with time; rates were similar after 5 years (77.1%, 75.7%, and 72.6% for COS; 91.7%, 90.6%, and 94.5% for CRFS, and 89.3%, 85.4%, and 78.3% in CRS, respectively). The 5Y COS, CRFS, and CRS were persistently lower in older patients even after 5 years.
Conditional survival estimates generally increase over time, and the largest improvements were observed for patients with advanced stage. Availability of updated prognosis at various time points allows clinicians to better guide their patients. Our results also imply substantial residual risk of recurrence and sustained excess mortality compared to the general population even after 5 years.