Colorectal cancer is the third most common cancer in the developed world, and the fourth leading cause of cancer deaths in the US.
Rare below 40 years of age. However, in the past 20 years 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.
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) has greatly reduced local recurrence and increased survival in selected cases.
The majority of colorectal cancers are adenocarcinomas derived from epithelial cells. About 66% of new colorectal cancers arise in the colon (43% in the proximal colon and 23% in the distal colon) and 30% occur in the rectum. 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, with 99% of cancers occurring in people aged 40 years or over.
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
Other diagnostic factors
- male sex
- abdominal pain
- weight loss and anorexia
- abdominal distension
- palpable lymph nodes
- increasing age
- family history
- adenomatous polyposis coli mutation
- Lynch syndrome (hereditary non-polyposis colorectal cancer)
- MUTYH/MYH-associated polyposis
- hamartomatous polyposis syndromes
- inflammatory bowel disease
- limited physical activity
- lack of dietary fibre
- moderate to heavy alcohol consumption
- low vitamin D
- consumption of red and processed meats
1st investigations to order
- full blood count
- liver biochemistry
- renal function
- CT colonography
- double-contrast barium enema
- CT scan of chest, abdomen, and pelvis
- genetic testing
Investigations to consider
- MRI pelvis: rectal cancer protocol
- transrectal endoscopic ultrasound
- carcinoembryonic antigen
- PET scan
- advanced optical imaging techniques
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
Regional Chief of Surgery
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
Alvin & Lois Lapidus Cancer Institute
PPK declares that she has no competing interests.
Kamila A. Nowak-Choi, MD
Department of Radiation Oncology
University of Maryland Upper Chesapeake Medical Center KCC Radiation Oncology
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 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 in gastrointestinal (GI) 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 GI cancer.
Susan Clark, BChir, MB
Consultant Colorectal Surgeon
St Mark's Hospital and Academic Institute
SC declares that she has no competing interests.
Steven Wexner, MD, FACS, FRCS, FRCS Ed, FASCRS, FAC
Chief of Staff
Department of Colorectal Surgery
SW declares that he has no competing interests.
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