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Colorectal cancer

Last reviewed: 2 Nov 2023
Last updated: 26 Sep 2023



History and exam

Key diagnostic factors

  • increasing age
  • rectal bleeding
  • change in bowel habit
  • rectal mass
  • positive family history
  • abdominal mass
More key diagnostic factors

Other diagnostic factors

  • anemia
  • male sex
  • abdominal pain
  • weight loss and anorexia
  • abdominal distension
  • palpable lymph nodes
Other diagnostic factors

Risk factors

  • increasing age
  • family history
  • adenomatous polyposis coli mutation
  • Lynch syndrome (hereditary nonpolyposis colorectal cancer)
  • MUTYH/MYH-associated polyposis
  • hamartomatous polyposis syndromes
  • inflammatory bowel disease
  • obesity
  • acromegaly
  • limited physical activity
  • lack of dietary fiber
  • smoking
  • moderate to heavy alcohol consumption
  • low vitamin D
  • consumption of red and processed meats
More risk factors

Diagnostic investigations

1st investigations to order

  • complete blood count
  • liver biochemistry
  • renal function
  • quantitative fecal immunochemical test
  • colonoscopy
  • CT colonography
  • double-contrast barium enema
  • CT scan of chest, abdomen, and pelvis
  • genetic testing
More 1st investigations to order

Investigations to consider

  • MRI pelvis: rectal cancer protocol
  • transrectal endoscopic ultrasound
  • biopsy
  • carcinoembryonic antigen
  • PET scan
More investigations to consider

Emerging tests

  • advanced optical imaging techniques

Treatment algorithm


rectal cancer, suitable for surgery

rectal cancer, not suitable for surgery

colon cancer, suitable for surgery

colon cancer, not suitable for surgery



David E. Stein, MD, FACS, FASCRS

Professor of Surgery

Georgetown University School of Medicine



Regional Chief of Surgery

MedStar Health




DES declares that he has no competing interests.

David M. Lisle, MD

Associate Program Director

Department of Surgery

MedStar Franklin Square Medical Center




DML declares that he has no competing interests.

Pallavi P. Kumar, MD

Division Director, Medical Oncology

Sinai and Northwest Hospital

LifeBridge Health

Alvin & Lois Lapidus Cancer Institute




PPK declares that she has no competing interests.

Kamila A. Nowak-Choi, MD

Assistant Professor

Department of Radiation Oncology

University of Maryland Upper Chesapeake Medical Center KCC Radiation Oncology

Bel Air



KANC declares that she has no competing interests.


Dr David E. Stein, Dr David M Lisle, Dr Pallavi P Kumar, and Dr Kamila A Nowak-Choi would like to gratefully acknowledge Dr Juan L. Poggio, Dr Jascha Rubin, Dr Najjia Mahmoud, Dr Emily Carter Paulson, Dr Gary Atkin, Dr Anne Ballinger, Dr Mark O'Hara, Dr Mark Harrison, and Dr Robert Glynne-Jones, previous contributors to this topic.


JLP, JR, NM, ECP, MOH, GA, and AB declare that they have no competing interests. MH is the chair of the Mount Vernon Upper GI Tumor Site Specific Group and a member of the National Cancer Research Institute anal, rectal, and advanced colorectal groups. He has also received honoraria for speaking and has been supported to attend international meetings on gastrointestinal cancer from Roche. He has also received research funding from Pfizer for a trial in rectal cancer. RGJ is the chief medical adviser to the charity Bowel Cancer UK. He has received honoraria for lectures from Roche, Sanofi, and Pfizer. He has received funding for the EXTRA study, involving capecitabine and radiotherapy in anal cancer, published in the International Journal of Radiation Biology Physics. RGJ has also received funding and free cetuximab for an ongoing phase 1/2 study integrating cetuximab into chemoradiation in rectal cancer, and has an agreement from Roche to supply bevacizumab for 3 months to 60 patients in one randomized phase 2 study as neoadjuvant chemotherapy in rectal cancer (BACCHUS). He has also been supported by Roche to attend international meetings in gastrointestinal cancer.

Peer reviewers

Susan Clark, BChir, MB

Consultant Colorectal Surgeon

St Mark's Hospital and Academic Institute

Northwick Park




SC declares that she has no competing interests.


Chief of Staff


Department of Colorectal Surgery

Cleveland Clinic




SW declares that he has no competing interests.

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