Colorectal Cancer Disease Summary

Overview

Colorectal cancer (CRC) is a carcinoma that arises from the epithelial lining of the colon or the rectum.  Rectal cancer is defined as cancerous lesions located ≤15 cm from the anal margin (with rigid proctoscopy) as stated in the Introduction section.

Colorectal cancer is the third most common cancer worldwide, accounting for 10% of all cancer cases. It is more common in males. Prevalence of the disease regionally can be found in the Epidemiology section.

Colorectal cancer is a multifactorial disease, with both environmental and genetic factors. The development of colorectal cancer is discussed in the Pathophysiology section.

The Risk Factors section discusses the different factors that can contribute to the development of colorectal cancer, some of which are age, family history and history of inflammatory bowel disease. Risk stratification is also in this section. 

History and Physical Examination

The Clinical Presentation section enumerates the manifestations of rectal, right-sided and left-sided colonic lesions.

As stated in the Physical Examination section, digital rectal examination (DRE) is an essential part of assessing patients suspected to have colorectal cancer.   

The primary goals of colorectal cancer screening are prevention and early detection. The Screening section discusses the tests done in screening the general population, patients with inflammatory bowel disease, personal history of colorectal cancer or cystic fibrosis, individuals with positive family history of colorectal cancer, patients after surgical or endoscopic removal of adenomatous polyps or sessile serrated polyps, special population (eg obese and smokers. Screening based on risk stratification is also in this section.

Diagnosis

Tests to assess patients suspected of having colorectal cancer are enumerated and discussed in the Laboratory Tests and Ancillaries and Imaging sections.

The Differential Diagnosis section enumerates the diseases that may also present with colorectal cancer, and these should be ruled out.

Management

The Evaluation section mentions the revised tumors, nodes, and metastasis (TNM) and pathologic stages of colorectal cancer proposed by the American Joint Committee on Cancer. Staging evaluation methods are also discussed in this section.

The Pharmacological Therapy section includes the discussion of drug options used in patients with colorectal cancer, divided into neoadjuvant and systemic therapies. These are also further divided based on whether the treatment is centered on colon versus rectal cancer. Drug options for metastatic disease are also enumerated.

Surgery based on anatomic location and extent of disease is an option for patients with colorectal cancer. Surgical techniques that can be done are enumerated and elaborated in the Surgery section.

Radiation therapy is recommended prior to, during, or after surgery, depending on the status of the disease. Radiotherapy procedures for unresectable nonmetastatic colon cancer, resectable nonmetastatic rectal cancer, and metastatic colorectal cancer are discussed in the Radiation Therapy section.

Primary prevention methods for colorectal cancer such as weight management, smoking cessation, etc are discussed in detail in the Prevention section.

Tests and assessments to be done in surveillance of patients with colorectal cancer are in the Monitoring section.