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.
Why You Still Need a Colonoscopy
1. Tumor Markers Are Not Diagnostic Tools
Low Sensitivity/Specificity: Tumor markers like CEA for colorectal cancer are primarily used to monitor patients after diagnosis and treatment, or to detect recurrence or metastasis. They are not designed for initial screening.
False Negatives Are Common: Many early-stage colon cancers or precancerous polyps do not produce elevated tumor marker levels. Up to 30% of people with colorectal cancer may have normal CEA levels, giving false reassurance.
Polyps Are the Target: The main goal of a colonoscopy is to find and remove precancerous polyps before they become cancerous. Tumor markers cannot detect these polyps.
2. The Indication for Colonoscopy Matters
The need for a colonoscopy depends on your risk factors, not tumor marker results. You likely still need the procedure if:
- Routine screening: You have reached the recommended age (45 or 50) and haven't had a colonoscopy in 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 genetic syndromes like Lynch syndrome.
- Symptomatic: You experience rectal bleeding, unexplained bowel changes, persistent abdominal pain, or iron deficiency anemia.
The bottom line: Colonoscopy remains the gold standard for colorectal cancer screening and prevention because it can both detect and remove precancerous polyps in one 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 broadcast media for over a decade and authored a book based on her 15-year radio program, "Healthy is Sexy Secrets ni Dr. Fritz." For questions, 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 dokatlaw@gmail.com. If you do not wish your letter published, we regret we cannot answer it. Thank you for understanding.
