Rising Rates of Colorectal Cancer In Younger Age Groups

New guidelines from the American Cancer Society have recommended screening should begin at age 45 for average-risk individuals. This is a revision down from the age of 50 years previously recommended. CRC screening has been shown to reduce mortality due to CRC.

Trends in colorectal cancer

Around the world, including in Singapore, we have seen a rise in the incidence of colorectal cancer over the last 30 years. A recent study in the USA also noted a significant increase in the detection of colorectal cancer in younger patients. In the cohort aged 18 to 44, there was an annual percentage change of 2.70%, and in the cohort aged 45 to 49, there was an annual percentage change of 4.15%.

What are the risk factors for colorectal cancer?

The main risks factors for colorectal cancer are increasing age, male gender, race (e.g. in Singapore, Chinese > Indian and Malays), family history, obesity, type 2 diabetes and smoking.

What is colorectal cancer screening?

Screening is defined as the presumptive identification of unrecognized disease in asymptomatic individuals by means of tests, examinations, or other procedures. CRC can arise from colorectal adenomas, or less commonly from flat neoplasms and serrated adenomas. The average time it takes for small adenomas to progress to cancer has not been definitely established, but on average, it is estimated that it probably takes about ten years. This interval time from polyp to cancer provides an opportunity for CRC screening. It allows the detection and removal of adenomas through polypectomy or even early-stage CRCs through endoscopic submucosal resection in asymptomatic individuals. Removal of the adenomas can prevent CRC.

Test options for colorectal cancer screening

Several test options are available for colorectal cancer screening:

Stool-based tests

• ●  Susceptible fecal immunochemical test (FIT) every year
• ●  Highly sensitive guaiac-based fecal occult blood test (gFOBT) every year
• ●  Multitarget stool DNA test (mt-sDNA) every 3 years

Visual (structural) exams of the colon and rectum

• ●  Colonoscopy every 10 years
• ●  Flexible sigmoidoscopy (FSIG) every 5 years

Screening for people at increased or high risk of CRC

People at increased or high risk of colorectal cancer might need to start colorectal cancer screening at an earlier age, be screened more often, and/or get specific tests. This includes people with:

• ●  Strong family history of colorectal cancer or certain types of polyps
• ●  Known family history of a hereditary colorectal cancer syndrome such as familial

adenomatous polyposis (FAP) or hereditary non-polyposis colon cancer (HNPCC or Lynch

Syndrome)

• ●  Personal history of radiation to the abdomen (belly) or pelvic area to treat a prior cancer
• ●  History of inflammatory bowel disease (ulcerative colitis or Crohn’s disease)
• ●  History of colorectal cancer or certain types of polyps

When should I see a specialist?

Patients should be referred to a specialist if they have a positive faecal occult blood test, prefer screening modalities such as colonoscopy or who have an increased risk of CRC.

Article written by Dr Mark Fernandes
Senior Consultant Gastroenterologist
gutCARE Digestive·Liver·Endoscopy Associates