RT Journal Article SR Electronic T1 Gastrointestinal oncology – what you need to know JF Clinical Medicine JO Clin Med FD Royal College of Physicians SP 575 OP 579 DO 10.7861/clinmedicine.12-6-575 VO 12 IS 6 A1 Elizabeth Smyth A1 David Cunningham YR 2012 UL http://www.rcpjournals.org/content/12/6/575.abstract