许多食管癌患者在术后原发灶和转移灶被切除,病理检测也为阴性,但最后仍死于肿瘤的转移和复发。这是因为在恶性肿瘤的早期病程,肿瘤细胞可能已播散到原发灶以外的远处组织与器官,这种播散或者说转移,不能被常规的临床手段所检测,往往成为肿瘤高致死率的一个重要因素。近些年来, Many patients with esophageal cancer after primary and metastatic lesions were removed, the pathological test was negative, but in the end still died of tumor metastasis and recurrence. This is because in the early course of malignancy, the tumor cells may have spread to distant tissues and organs other than the primary tumor. Such dissemination or metastasis can not be detected by conventional clinical means and often become highly tumorous Rate is an important factor. In recent years,