Stage II colorectal cancer is divided into stage IIA, stage IIB, and stage IIC. In stage IIA, cancer has spread through the muscle layer of the colon and/or rectal wall to the serosa (outermost layer) of the colon and/or rectal wall. In stage IIB, cancer has spread through the serosa of the colon and/or rectal wall but has not spread to nearby organs. In stage IIC, cancer has spread through the serosa of the colon and/or rectal wall to nearby organs. Also called Dukes B colorectal cancer.