Our patients elect to have colon cancer screening to avoid death – not just death from cancer but what medicine refers to as all-cause mortality.
If colon cancer screening catches a patient’s colon cancer early or the colonoscopist removes a polyp, which perhaps would have turned into colon cancer, the idea is that this person then would end up with more healthy life-years.
It would not be the desired outcome if we only decreased colorectal-cancer-related death but not overall death.
Roof Replacement Analogy
A roof might be repaired when it starts looking worn out. The main goal is to prevent water from entering the home and damaging inner structures.
Preventing water from getting into the house is the main outcome. In the same way, adding more life-years would be the desired outcome of colon cancer screening.
If the roofer said that the roof replacement fixed the damaged shingles, but the water still got in, it would be a futile intervention.
Does Colon Cancer Extend Your Life?
We’re unsure as to whether colon cancer screening and even polypectomy can extend your life because we don’t have enough studies to determine if colon cancer screening can decrease all-cause mortality.
We know screening decreases cancer-related deaths, but that’s different from all-cause mortality.
This study, for example, only measures cancer-related death. The results are relevant but inadequate to decide whether to screen for colon cancer.
After pooling together several studies, this study found a 1% decrease in all-cause mortality.
The terms to look for are:
- mortality reduction (MR)
- life years gained (LYG)
- quality-adjusted life year (QALY)
Colon Cancer Screening Options
When advising patients at Digital Nomad Health, we determine the risks and benefits and how motivated patients are regarding screening.
Stool Testing
There are 3 ways we test for colon cancer using stool testing:
- looking for blood cells (FOBT)
- antibody testing for blood (FIT)
- DNA testing (FIT-DNA test)
FOBT
The physician performs a rectal exam and tests the stool on the spot.
The patient would send a stool sample to the lab and the technician would use a chemical to look for the heme molecule.
Clinicians commonly use the Hemoccult brand, which is relatively easy to collect.
FIT
Just like the FOBT test, the FIT test looks for the heme molecule but uses antibodies that bind to the hemoglobin molecule, increasing its accuracy.
FIT-DNA
This test combines hemoglobin antibody testing and any abnormal DNA shed from the colon’s lining.
Clinicians commonly use Cologuard for testing.
Colonoscopy
Some patients elect to be sedated for this procedure; you go to sleep, wake up, and it’s completed.
The memorable part of this procedure is the explosive moments spent on the toilet the night before the procedure, ensuring a clean colon for camera visualization.
Imaging Studies
Referred to as a virtual colonoscopy, a CT scan examines the entire colon and identifies any suspicious lesions.
An MRI can also be used, but it isn’t commonly used and requires experienced MRI technicians, proper protocols, and a radiologist capable of reviewing such screening studies.