So for example, if a tumor has invaded the esophageal submucosa but it hasn't spread to lymph nodes or distant organs, it's categorized as T1, N0, M0, which falls under stage I.

举个例子，如果食管癌已经入侵了食管黏膜下层，但还没有转移至淋巴结或远端器官，那就可以被分为T1、N0、M0，意味着处于I期。