In pubmed, bowel cancer was the eatliest term, which included colon cancer and rectal cancer. Colorectal cancer occurring in 1945 was equal to bowel cancer. Authors of most paper don’t clearly differiate them.For exapmle, colon cancer is more than rectal cancer. When the authors in one hospital maybe only meet colon cancer during a particular period, they may be refer to colon cancer. In fact, many terms were used to describe a ting and biring confused, the terms shoud be unitfored.