The effect of tumor locations of esophageal cancer on the metastasis to liver or lung

Dashan Ai, Yun Chen, Qi Liu, Jiaying Deng, Kuaile Zhao


Background: Liver and lung are the most common metastatic sites for esophageal cancer. Tumor location of esophageal cancer has been a prognostic factor of tumor, node and metastasis (TNM) staging system since 2009. However, the relationship between tumor location and metastatic sites remains unclear.
Methods: Patients with esophageal cancer were derived from surveillance, epidemiology and end results (SEER) database from 2010 to 2013. Age, sex, histologic type and grade were included in the model for propensity score matching between patients with or without liver and lung metastasis. After propensity score matching, the relationship between tumor location and the probability of liver or lung metastasis was analyzed using chi-square analysis. Overall survival was analyzed between different locations within liver or lung metastasis patients.
Results: A total of 6,812 patients were eligible. After matching, primary site was still an independent risk factor for both liver and lung metastasis. For patients with liver metastasis, lower esophagus was more likely to be the primary site than upper segment (P=0.014). In contrast, lung metastasis was more likely to be found in patients with upper esophageal cancer than lower segment (P=0.033). In liver metastasis group, those with upper esophageal cancer had the worst survival, followed by middle and lower segment and the results are opposite in lung metastasis group.
Conclusions: These findings are useful in the evaluation when diagnose and follow up. Targeted examinations in accordance with tumor location will assist to find early metastasis and deliver treatment timely and properly.