Worldwide trends in esophageal cancer survival, by sub-site, morphology, and sex: an analysis of 696,974 adults diagnosed in 60 countries during 2000-2014 (CONCORD-3).

BACKGROUND: Esophageal cancer survival is poor worldwide, though there is some variation. Differences in the distribution of anatomical sub-site and morphological sub-type may help explain international differences in survival for all esophageal cancers combined. We estimated survival by anatomic sub-site and morphological sub-type to understand further the impact of topography and morphology on international comparisons of esophageal cancer survival. METHODS: We estimated age-standardized one-year and five-year net survival among adults (15-99 years) diagnosed with esophageal cancer in each of 60 participating countries to monitor survival trends by calendar period of diagnosis (2000-2004, 2005-2009, 2010-2014), sub-site, morphology, and sex. RESULTS: For adults diagnosed during 2010-2014, tumors in the lower third of the esophagus were the most common, followed by tumors of overlapping sub-site and sub-site not otherwise specified. The proportion of squamous cell carcinomas diagnosed during 2010-2014 was generally higher in Asian countries (50%-90%), while adenocarcinomas were more common in Europe, North America and Oceania (50%-60%). From 2000-2004 to 2010-2014, the proportion of squamous cell carcinoma generally decreased, and the proportion of adenocarcinoma increased. Over time, there were few improvements in age-standardized five-year survival for each sub-site. Age-standardized one-year survival was highest in Japan for both squamous cell carcinoma (67.7%) and adenocarcinoma (69.0%), ranging between 20%-60% in most other countries. Age-standardized five-year survival from squamous cell carcinoma and adenocarcinoma was similar for most countries included, around 15%-20% for adults diagnosed during 2010-2014, though international variation was wider for squamous cell carcinoma. In most countries, survival for both squamous cell carcinoma and adenocarcinoma increased by less than 5% between 2000-2004 and 2010-2014. CONCLUSIONS: Esophageal cancer survival remains poor in many countries. The distributions of sub-site and morphological sub-type vary between countries, but these differences do not fully explain international variation in esophageal cancer survival.