Changing patterns in presentation and therapy of esophagogastric junction cancers in the United States.

Abstract

22 Background: Esophagogastric junction cancer (EGJC) has recently been included within the esophageal cancer (EC) AJCC TNM staging criteria. Trends in clinical presentation, therapeutic approach and outcomes are of interest. Methods: We identified EGJCs from the U.S. population SEER database and examined incidence, demographic, therapeutic and outcomes information. Siewert classification-related EGJC subtype-associated findings were also examined. Results: EGJC age-adjusted incidence rates (x10-5) have increased from 3.3 in 1973 to 7.5 in 2009. While the incidence rate for females has remained around 2, rates in males have increased from 6 to 13. Among 30,710 EGJC patients diagnosed between 1992 and 2009, potentially curative resection increased from 31% to 36% and radiation increased from 32% to 41% (p<0.0001). For resected EGJCs, significant trends over time include: increased total LN count (mean: 15.5 vs. 12.3), fewer positive LNs (3.1 vs. 4), smaller tumor size (29% vs. 36% >5 cm), lower T category (39% vs. 29% T1/2), lower N category (42% vs. 35% N0), lower stage group (29% vs. 38% stage 3/4), increased preoperative radiation (26% vs. 3%), decreased 90-day mortality (6.5 vs. 14.1%), longer overall survival (OS, median: 2.9 vs. 1.7 years) and longer disease-specific survival (median: 3.9 vs. 2.0 years) (all at p<0.0001). Multivariate predictors of OS include TNM categories, age, ethnicity, radiation, and total LN count (all at p<0.0001). There were significant differences in stage-for-stage OS between EC subtypes based on histology and primary tumor location, and in DSS between EGJC subtypes (Siewert I, II or III) as well. Conclusions: EGJC incidence rates, diagnosis and treatment have undergone significant changes within the U.S. population. The regional dissection extent remains an area of importance as it is associated with OS. Comparisons of various survival outcomes do not support using the same staging criteria for EGJC as for EC.