title: Rectal and colon cancer: Not just a different anatomic site.
abstract: Due to differences in anatomy, primary rectal and colon cancer require different staging procedures, different neo-adjuvant treatment and different surgical approaches. For example, neoadjuvant radiotherapy or chemoradiotherapy is administered solely for rectal cancer. Neoadjuvant therapy and total mesorectal excision for rectal cancer might be responsible in part for the differing effect of adjuvant systemic treatment on overall survival, which is more evident in colon cancer than in rectal cancer. Apart from anatomic divergences, rectal and colon cancer also differ in their embryological origin and metastatic patterns. Moreover, they harbor a different composition of drug targets, such as v-raf murine sarcoma viral oncogene homolog B (BRAF), which is preferentially mutated in proximal colon cancers, and the epidermal growth factor receptor (EGFR), which is prevalently amplified or overexpressed in distal colorectal cancers. Despite their differences in metastatic pattern, composition of drug targets and earlier local treatment, metastatic rectal and colon cancer are, however, commonly regarded as one entity and are treated alike. In this review, we focused on rectal cancer and its biological and clinical differences and similarities relative to colon cancer. These aspects are crucial because they influence the current staging and treatment of these cancers, and might influence the design of future trials with targeted drugs.
authors.affiliation: Department of Medical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: K
authors.initials: K
authors.lastname: Tamas
authors.affiliation: Department of Medical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: A M E
authors.initials: AM
authors.lastname: Walenkamp
authors.affiliation: Department of Medical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: E G E
authors.initials: EG
authors.lastname: de Vries
authors.affiliation: Department of Medical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: M A T M
authors.initials: MA
authors.lastname: van Vugt
authors.affiliation: Department of Radiology, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: R G
authors.initials: RG
authors.lastname: Beets-Tan
authors.affiliation: Department of Surgery, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: van Etten
authors.affiliation: Department of Medical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: D J A
authors.initials: DJ
authors.lastname: de Groot
authors.affiliation: Department of Medical Oncology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands. Electronic address: g.a.p.hospers@umcg.nl.
authors.forename: G A P
authors.initials: GA
authors.lastname: Hospers
mesh_terms: D059186:Chemoradiotherapy, Adjuvant / Q000379:methods*; D003110:Colonic Neoplasms / Q000453:epidemiology / Q000235:genetics / Q000473:pathology / Q000628:therapy; D013505:Digestive System Surgical Procedures / Q000379:methods*; D019468:Disease Management; D066246:ErbB Receptors / Q000235:genetics*; D006801:Humans; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D012004:Rectal Neoplasms / Q000453:epidemiology / Q000235:genetics / Q000473:pathology / Q000628:therapy; D016019:Survival Analysis
chemical_list: C512478:EGFR protein, human; D066246:ErbB Receptors; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf
keywords: Epidemiology; Metastasis; Molecular markers; Rectal and colon cancer; Staging; Treatment