Management of colorectal cancer is complex and requires a multidisciplinary approach. Accordingly, this book is written mainly by expert medical oncologists, but radiotherapists, biologists, surgeons and statisticians have also given their contribution. The six chapters highlight the most recent developments (and failures) in the medical treatment of colorectal cancer. In the first half of this six chapter book, the focus is on the postoperative treatment of radically resected stage II–III cancer and on the special case of extraperitoneal rectal cancer. In the second half, the challenges of treating the advanced disease are addressed.