Divergent Metastatic Patterns Between Esophageal Squamous-cell Carcinoma and Esophageal Adenocarcinoma: a Propensity-matched Analysis

Abstract Background: To explore the different metastatic patterns between esophageal squamous-cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC).Methods: For this propensity-matched analysis, we used data from the latest iteration of the Surveillance, Epidemiology, and End Results (SEER) database and included patients diagnosed with esophageal cancer from 2010 to 2017. Results: A total of 20,189 patients were identified, including 6,610 ESCC and 13,579 EAC. After propensity score matching, 4597 pairs were selected. Compared with ESCC, EAC had a higher rate of liver metastasis (P < 0.001) and brain metastasis (P < 0.001), and a lower rate of lung metastasis (P < 0.001), with no significant difference in bone metastasis (P = 0.255). The liver preferentially co-metastasized with lung in both cohorts. Brain metastasis was commonly observed in combination with other organ metastases in EAC. Conclusions: There are major differences in metastatic patterns between ESCC and EAC. The patterns identified may reflect the underlying biology of metastatic esophageal cancer and have potential to influence future monitoring strategies depending on clinical settings.