Dear Dr. Fritz,
Good day. All of my tumor markers are normal. Do I still need to undergo a colonoscopy? Thanks for your reply.
Lady Godiva
Dear Lady Godiva,
Yes. You still need to undergo a colonoscopy despite having normal tumor markers.
While having normal tumor markers can be reassuring, they do not eliminate the need for a
colonoscopy in many situations. In fact, the general medical consensus is that tumor markers are not reliable screening tools for colon cancer.
Here is a breakdown of why you may still need a colonoscopy, even with the normal tumor
Markers:
1. Tumor markers are not diagnostic tools
Low Sensitivity/Specificity: Tumor markers (like CEA for colorectal cancer) are primarily used to monitor a patient after they have been diagnosed and treated for cancer, or to see if the cancer has spread or returned.
False Negatives are Common: Many early-stage colon cancers or precancerous polyps do not produce elevated levels of tumor markers. Up to 3 out of 10 people with colorectal cancer may have normal CEA levels. Therefore, a normal result can give false reassurance.
Polyps are the Target: The main purpose of a colonoscopy is to find and remove precancerous polyps before they ever turn into cancer. Tumor markers cannot detect these polyps.
2. The Indication for the colonoscopy matters
The necessity of a colonoscopy is based on your risk factors, not the tumor marker results. You likely still need the procedure if:
Routine screening: You have reached the recommended age for screening (typically starting at age 45 or 50) and have not had a colonoscopy in the last 10 years.
Increased risk: You have a personal history of polyps or inflammatory bowel disease (Crohn’s or Ulcerative Colitis).
High risk: You have a strong family history of colon cancer or certain genetic syndromes (like Lynch syndrome).
Symptomatic: You are experiencing symptoms like rectal bleeding, unexplained changes in bowel habits, persistent abdominal pain, or unexplained iron deficiency anemia.
The bottom line is, colonoscopy remains the Gold Standard for colorectal cancer screening and prevention because it is the only test that can both detect and remove precancerous polyps in the same procedure.
Dr. Fritz
(Dr. Fritz Legarde Espedilla is an aesthetic dermatologist, surgeon, and clinical sexologist. She is also trained in hypnotherapy and Medical Acupuncture. She has been in the broadcast media for more than a decade and has written a book based on her 15-year stint
with her radio program, “Healthy is Sexy Secrets ni Dr. Fritz.” For your questions, you may
send them to Dear Dr. Fritz, c/o Sunstar- Davao Publishing Inc., Door 11, Ebro-Pelayo
Building 1, Juan Luna St., Barangay 29-C, Davao City, or email them to dokatlaw@gmail.com . If you don’t wish your letter to be published, we regret that we cannot answer them. Thank you for your understanding.)
