Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum (parts of the large intestine). Signs and symptoms may include blood in the stool, a change in bowel movements, weight loss, and fatigue.

Most colorectal cancers are due to old age and lifestyle factors, with only a small number of cases due to underlying genetic disorders. Risk factors include diet, obesity, smoking, and lack of physical activity. Dietary factors that increase the risk include red meat, processed meat, and alcohol.  Another risk factor is inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis. Some of the inherited genetic disorders that can cause colorectal cancer include familial adenomatous polyposis and hereditary non-polyposis colon cancer; however, these represent less than 5% of cases. It typically starts as a benign tumor, often in the form of a polyp, which over time becomes cancerous.

Bowel cancer may be diagnosed by obtaining a sample of the colon during a sigmoidoscopy or colonoscopy. This is then followed by medical imaging to determine if the disease has spread. Screening is effective for preventing and decreasing deaths from colorectal cancer.  Screening, by one of a number of methods, is recommended starting from the age of 50 to 75. During colonoscopy, small polyps may be removed if found.  If a large polyp or tumor is found, a biopsy may be performed to check if it is cancerous. Aspirin and other non-steroidal anti-inflammatory drugs decrease the risk. Their general use is not recommended for this purpose, however, due to side effects.

Treatments used for colorectal cancer may include some combination of surgery, radiation therapy, chemotherapy and targeted therapy. Cancers that are confined within the wall of the colon may be curable with surgery, while cancer that has spread widely is usually not curable, with management being directed towards improving quality of life and symptoms. 

 Signs and symptoms

The signs and symptoms of colorectal cancer depend on the location of the tumor in the bowel, and whether it has spread elsewhere in the body (metastasis). The classic warning signs include: worsening constipation, blood in the stool, decrease in stool caliber (thickness), loss of appetite, loss of weight, and nausea or vomiting in someone over 50 years old. Around 50% of individuals with colorectal cancer do not report any symptoms.

Rectal bleeding or anemia is high-risk symptoms in people over the age of 50. Weight loss and changes in a person's bowel habit are typically only concerning if they are associated with rectal bleeding.

Cause

• Inflammatory bowel disease
• Genetics

Diagnosis

• Medical imaging
• Histopathology
• Staging

Prevention

• Lifestyle
• Medication and supplements
• Screening

Treatment

• Surgery
• Chemotherapy
• Radiation therapy
• Immunotherapy
• Palliative care
• Follow-up
• Exercise

Journal of Cancer Research and Immuno-Oncology is an open access rapid peer reviewed journal in the field of cancer research. Journal announces papers for the upcoming issue. Interested can submit their manuscript through online portal.

Submit manuscript at https://www.longdom.org/submissions/cancer-research-immuno-oncology.html or send as an e-mail attachment to the Editorial Office at immunooncology@emedscholar.com

Media contact:

Maegan Smith

Managing Editor

Journal of Cancer Research and Immuno-Oncology

Mail ID: immunooncology@emedscholar.com

WhatsApp:  +1-504-608-2390