Most colorectal cancers begin as a growth, or tumor, on the inner lining of the colon or rectum called a polyp, and they can change to cancer over many years.

大多数结肠癌刚开始是在结肠或直肠内表面生长出息肉，经数年后会变成肿瘤。

youdao

Most colorectal cancers begin as a growth, or tumor, on the inner lining of the colon or rectum called a polyp, and they can change to cancer over many years.

大多数结肠癌刚开始是在结肠或直肠内表面生长出息肉，经数年后会变成肿瘤。

youdao