P-101 Conditional relative survival in non-metastatic esophagogastric cancer between 2006 and 2019: A population-based study

Abstract

Overall survival estimates are informative at primary diagnosis but become less relevant over time. Conditional survival is an accurate method to estimate the life expectancy of patients after a certain number of years. The aim of our study is to assess the 3-year conditional relative survival of patients with non-metastatic esophageal or gastric cancer receiving treatment with curative intent. We selected patients with non-metastatic esophageal or gastric cancer diagnosed between 2006-2019 who received treatment with curative intent from the Netherlands Cancer Registry. The relative survival was calculated using the Ederer II method. The relative 3-year survival was calculated from diagnosis and for each additional year survived, i.e. the conditional relative survival. Analyses were performed by stratification of tumor location (esophageal or gastric) and (clinical) tumor stage. Three-year relative survival conditional on having survived 1-, 3- and 5- years was 58%, 77% and 86% for patients with esophageal cancer and 66%, 81% and 90% for patients with gastric cancer, respectively. The conditional 3-year relative survival of patients with esophageal cancer who underwent a resection having survived 3 years was 90%, 87%, 75% and 58% for tumor stage 0, I, II and III. For patients with esophageal cancer who received chemoradiotherapy this was 50% and 65% for clinical tumor stage II and III, respectively. The conditional 3-year relative survival of patients with gastric cancer who underwent a resection having survived 3 years was 98%, 89%, 71% and 56% for tumor stage 0, I, II and III, respectively. Despite poor survival of patients with esophageal or gastric cancer from diagnosis, the survival of patients on having survived additional years improved with every year that passed. Our results are relevant for the clinical practice to more accurately inform patients of their life expectancy after time since diagnosis passes.