Colorectal cancer

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Last reviewed: 18 Jul 2025

Last updated: 24 Jan 2025

Colorectal cancer is the third most common cancer in the developed world.

It is rare below 40 years of age. However, there has been a significant increase in colorectal cancer incidence among younger adults, especially in developed countries. The rise in early onset disease may be related to changes in diet and resultant effects on gut microbiome and inflammation and to environmental factors such as use of microplastics.

Symptoms are not specific and occur frequently in benign colorectal conditions.

Surgical resection is the main curative treatment.

Combined multi-modality treatment (chemotherapy, radiotherapy, immunotherapy, resection of metastases) greatly reduces local recurrence and increases survival in selected cases.

Definition

The majority of colorectal cancers are adenocarcinomas derived from epithelial cells. About 63% of new colorectal cancers arise in the colon (39% in the proximal colon and 24% in the distal colon), and 30% occur in the rectum.[1] Less common types of malignant colorectal tumours are carcinoid tumours, gastrointestinal stromal cell tumours, and lymphomas. Increasing age is the greatest risk factor for sporadic colorectal adenocarcinoma.

History and exam

Key diagnostic factors

presence of risk factors
increasing age
rectal bleeding
change in bowel habit
rectal mass
positive family history
abdominal mass

Full details

Other diagnostic factors

abdominal pain
anaemia
male sex
weight loss and anorexia
abdominal distension
palpable lymph nodes

Full details

Risk factors

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

Full details

Diagnostic investigations

1st investigations to order

full blood count
liver biochemistry
renal function
quantitative faecal immunochemical test
colonoscopy
CT colonography
CT scan of chest, abdomen, and pelvis
genetic testing

Full details

Investigations to consider

MRI pelvis: rectal cancer protocol
transrectal endoscopic ultrasound
biopsy
carcinoembryonic antigen
PET scan

Full details

Emerging tests

advanced optical imaging techniques
blood-based tests
circulating tumour DNA

Treatment algorithm

ACUTE

rectal cancer, suitable for surgery

rectal cancer, not suitable for surgery

colon cancer, suitable for surgery

colon cancer, not suitable for surgery

Contributors

Authors

David E. Stein, MD, MHCM, FACS, FASCRS

Professor of Surgery

Georgetown University School of Medicine

Georgetown

Regional Chief of Surgery

MedStar Health

Baltimore

Disclosures

DES declares that he 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

Declarações

KANC declares that she has no competing interests.

Agradecimentos

Dr David E. Stein and Dr Kamila A. Nowak-Choi would like to gratefully acknowledge Dr Pallavi P. Kumar, Dr David M. Lisle, 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.

Declarações

PPK, DML, 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 Tumour 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 randomised phase 2 study as neoadjuvant chemotherapy in rectal cancer (BACCHUS). He has also been supported by Roche to attend international meetings in gastrointestinal cancer.

Revisores

Susan Clark, BChir, MB

Consultant Colorectal Surgeon

St Mark's Hospital and Academic Institute

Northwick Park

Middlesex

Declarações

SC declares that she has no competing interests.

Steven Wexner, MD, FACS, FRCS, FRCS Ed, FASCRS, FAC

Chief of Staff

Chairman

Department of Colorectal Surgery

Cleveland Clinic

Weston

Declarações

SW declares that he has no competing interests.

Referências

Nossas equipes internas de editoria e de evidências trabalham em conjunto com colaboradores internacionais especializados e pares revisores para garantir que forneçamos acesso às informações o mais clinicamente relevantes possível.

Principais artigos

National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology: colorectal cancer screening [internet publication].Texto completo

National Institute for Health and Care Excellence. Colorectal cancer. Dec 2021 [internet publication].Texto completo

National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology: rectal cancer [internet publication].Texto completo

National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology: colon cancer [internet publication].Texto completo

Artigos de referência

Uma lista completa das fontes referenciadas neste tópico está disponível para os usuários com acesso total ao BMJ Best Practice.

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Colorectal cancer

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic investigations

1st investigations to order

Investigations to consider

Emerging tests

Treatment algorithm

rectal cancer, suitable for surgery

rectal cancer, not suitable for surgery

colon cancer, suitable for surgery

colon cancer, not suitable for surgery

Contributors

Authors

David E. Stein, MD, MHCM, FACS, FASCRS

Disclosures

Kamila A. Nowak-Choi, MD

Declarações

Agradecimentos

Declarações

Revisores

Susan Clark, BChir, MB

Declarações

Steven Wexner, MD, FACS, FRCS, FRCS Ed, FASCRS, FAC

Declarações

Referências

Principais artigos

Artigos de referência

Uma lista completa das fontes referenciadas neste tópico está disponível para os usuários com acesso total ao BMJ Best Practice.

Diagnósticos diferenciais

Diretrizes

Folhetos informativos para os pacientes

Conectar-se ou assinar para acessar todo o BMJ Best Practice

Conectar-se ou assinar para acessar todo o BMJ Best Practice

Conectar-se para acessar todo o BMJ Best Practice