After the removal of esophageal cancer, there is indeed a possibility of recurrence. This is because not only are there tumors on the esophagus, but some mediastinal lymph nodes around the esophagus may also have metastasized. It must be acknowledged that thoracic surgeons will definitely remove the tumor completely during surgery, but they can only remove the tumors that are visible to the naked eye. Many tumor cells that cannot be seen by the naked eye are impossible to remove. If the cancer is at a relatively advanced stage, many of these invisible tumor cells cannot be eliminated, just like air is invisible but still exists. Therefore, invisible does not mean there are no cancer cells. Thus, if there is no follow-up auxiliary treatment to kill the cancer cells, the cancer may very likely recur.