Advanced Health Tune Up

CANCER - COLON

Definition

Colorectal cancer is the third most common cancer in both men and women in the United States. Risk factors include age, a diet rich in fat and cholesterol, inflammatory bowel disease (especially ulcerative colitis), and genetic predisposition, including hereditary polyposis and nonpolyposis syndromes. If detected early, colorectal cancer is curable by surgery. Adjuvant chemotherapy can prolong survival in disease that has reached the lymph nodes. Both systemic and locoregional chemotherapy (e.g., intrahepatic intra-arterial chemotherapy for liver metastases) have a role in patients with metastatic colon cancer. Radiotherapy is used in cases of rectal cancer to reduce the risk of local recurrence. Long-term survival correlates with disease stage in colorectal cancer. Progress has been made in understanding the molecular basis of colorectal cancer predisposition and progression. Efforts are underway to develop better screening strategies, chemopreventive approaches, and novel therapies to improve patient survival rates and to minimise toxicity. Despite all efforts, colorectal cancer remains the third leading cause of death from cancer in the United States. Recent advances have included the development of orally available forms of 5-fluorouracil (5-FU) and the demonstration that anti-vascular endothelial growth factor (VEGF) therapy with bevacizumab prolongs survival in advanced colorectal cancer when combined with irinotecan, 5-FU, and leucovorin.

Aetiology / Risk Factors

Living in an industrialised country

African American origin; however, incidence of colorectal cancer in Africa is the lowest in the world

Age over 50

Diets high in meat, and, possibly, low in fruits and vegetables

High body mass index

Regular alcohol use—diets rich in fruits and vegetables may counter this risk; particularly high risk when combined with tobacco use

Smoking—particularly with 35 year history

Family history—particularly if first-degree relative developed colorectal cancer prior to age 50; if family member(s) developed colorectal cancer or polyps after age 60, there is no greater risk for the individual

Inflammatory bowel disease, particularly ulcerative colitis—must undergo surveillance, including mucosal biopsies and brushings, for colonic dysplasia: transformation to malignancy may be difficult to detect given that symptoms of bloody diarrhoea, abdominal pain, and obstruction often represent a flare of inflammatory bowel disease.