Colorectal cancer is one of the cancers that can be prevented if abnormalities are detected before symptoms appear. This is why global screening guidelines emphasize risk assessment starting at age 45.
“I have no symptoms. Why does the doctor recommend colorectal cancer screening?” This is a common question gastroenterologists hear. Many people think screening is only for those who already have symptoms, such as
In reality, early-stage colorectal cancer and certain types of polyps that may develop into cancer often show no symptoms at all.
This is why current care guidelines have shifted from treating disease after it occurs to detecting abnormalities before symptoms arise.
What many may not know is that most colorectal cancers do not develop suddenly. Before becoming cancerous, changes occur sequentially in the colon lining, starting with small polyps (polyps) that gradually change into
precancerous abnormalities and may later develop into colorectal cancer. This process can take several years, meaning that early detection and removal of abnormalities can help prevent cancer development.
Before the disease progresses to a more severe stage, colorectal cancer is one of the few cancers where screening plays a role in both detection and prevention.
In recent years, many countries have seen an increase in colorectal cancer among people under 50. This data has led several countries to recommend that the general population begin risk assessment at age 45. The American Cancer Society (ACS) and U.S. Preventive Services Task Force (USPSTF) are among the organizations that have updated their guidelines accordingly.
Although not everyone needs the same type of screening, age 45 is a suitable time to discuss personal risk with a doctor.
Groups who should consult a doctor about early screening include those who:
Many people associate screening with disease detection, but modern medical perspectives emphasize that the key goal is not only to find existing cancer.
Doctors aim to detect abnormalities that could become cancer in the future. The earlier these are found, the more likely they can be managed before the disease advances.
This concept makes colorectal cancer screening today more than diagnosis—it is part of disease prevention.
A major challenge in screening is that some polyps are very small or flat, making them difficult to see.
Currently, AI technology is being used to assist in real-time image analysisduring colonoscopy procedures.This supports physicians' evaluations during examinations.
At the Colorectal Health Center of Samitivej Sukhumvit Hospital, the AI-assisted Colonoscopy system called EndoBRAIN-EYE has been integrated into screening protocols.
In gastroenterology endoscopy, an important quality metric is the Adenoma Detection Rate (ADR).
ADR measures the rate of detecting adenomatous polyps, which are precancerous lesions that may develop into colorectal cancer.
This metric is important because the higher the early detection rate, the greater the chance to prevent future colorectal cancer.
The American Society for Gastrointestinal Endoscopy (ASGE) sets the ADR benchmark at 35%, while data from Samitivej Sukhumvit’s Colorectal Health Center shows a rate of 40%.
Beyond detection rates, safety indicators and clinical outcomes are continuously monitored to improve long-term patient care quality.
The key goal of screening is not just to detect disease earlier but to alter disease progression before it advances.
Data from Samitivej Sukhumvit’s Colorectal Health Center shows that AI-assisted Colonoscopy as part of screening has doubled adenoma detection rates and improved polyp detection in high-risk groups.
This has led to a 60% reduction in detection of advanced-stage disease and an increase in early-stage detection.
The care approach at Samitivej Sukhumvit’s Colorectal Health Center emphasizes prevention, early detection of abnormalities, and the use of technology to enhance screening quality.
These achievements contributed to Samitivej Sukhumvit Hospital receiving the Colorectal Cancer Service Provider of the Year in Asia-Pacific 2026 award from the Global Health Asia-Pacific Awards 2026, reflecting their commitment to advancing prevention, early detection, and comprehensive colorectal cancer care.
Acknowledgments Dr. Rewat Boonanuwat, MD 37004, a gastroenterologist and advanced endoscopy specialist,Samitivej Sukhumvit Hospital