Patterns of Distant Metastasis Between Histological Types in Esophageal Cancer

Abstract

<b>Introduction:</b> Distant metastasis remains the major cause of treatment failure in esophageal cancer, though there have been few large-scale studies of the patterns of distant metastasis in different histological types. We investigated the patterns of distant metastasis in esophageal adenocarcinoma (AC) and squamous cell carcinoma (SCC) using a population-based approach. <b>Methods:</b> Patients with <i>de novo</i> stage IV esophageal cancer at diagnosis were identified using the Surveillance, Epidemiology, and End Results database. Multivariable logistic regression was performed to identify potential risk factors for site-specific distant metastasis to the distant lymph nodes, bone, liver, brain, and lung at diagnosis. <b>Results:</b> We identified 1,470 patients with complete data for analysis including 1,096 (74.6%) patients with AC and 374 (25.4%) patients with SCC. A total of 2,243 sites of distant metastasis were observed, the liver was the most common site of distant metastasis (727, 32.4%), followed by the distant lymph nodes (637, 28.4%), lung (459, 20.5%), bone (344, 15.3%), and brain (76, 3.4%). Multivariable logistic regression showed that compared to patients with SCC, patients with AC were more likely to have metastasis to the brain (odds ratio [OR] 3.026, 95% confidence interval [CI] 1.441-6.357, <i>p</i> = 0.003) and liver (OR 1.848, 95% CI 1.394-2.451, <i>p</i> < 0.001), and less likely to have metastasis to the lung (OR 0.404, 95% CI 0.316-0.516, <i>p</i> < 0.001). Histological type had no effect on metastasis to the distant lymph nodes or bone. <b>Conclusions:</b> Patients with esophageal AC are more likely to present with liver and brain metastases, and less likely to present with lung metastasis than patients with esophageal SCC.