Colorectal cancer screening and surveillance

What it is

Screening for colorectal cancer is recommended for average-risk individuals beginning at age 50. National guidelines vary, and it is generally advised to start routine colon cancer screening between ages 45 and 50. Between ages 75 and 85 screening is more individualized. The factors to weigh are life expectancy, the patient's overall health, whether the patient has been screened previously, and patient preference. Most guidelines recommend stopping colon cancer screening in patients older than 85 years, or when life expectancy falls below 10 years.

Causes and risk

Higher risk means a personal history of adenomatous polyps, colorectal cancer, inflammatory bowel disease or a genetic cancer syndrome, or a family history of adenomatous polyps or colorectal cancer. The family history sets the age:

• A first degree relative with colorectal cancer or adenomatous polyps found before age 60, or two or more first degree relatives at any age with colorectal cancer or advanced adenoma: colonoscopy from age 40, or 10 years before the youngest age at which a family member was diagnosed, whichever comes first. The maximum surveillance interval is then 5 years.
• A single first degree relative diagnosed at age 60 or older, or two affected second degree relatives: screening from age 40 by any recommended method, at the same intervals as average risk.

A second page names the risk factors at greater length: aging over 40; family history of colorectal cancer, familial adenomatous polyposis, Peutz-Jeghers syndrome, juvenile polyposis syndrome or hereditary nonpolyposis colorectal cancer; a past history of colorectal adenomas, serrated polyps or inflammatory bowel disease; and smoking, alcohol, obesity and radiation. On that page the ages are 45-75 years with no risk factors, and with high risk factors before 10 years or at the age of 40 yrs.