About a third of eligible Americans skip colorectal cancer screening. It is a dangerous gamble.
The American Cancer Society has updated its rules. A simple blood test is now an option. It sits alongside colonoscopies and stool tests for people at average risk.
Colorectal cancer kills more Americans under 50 than any other cancer type. Detection changes everything.
“Early detection truly saves lives.” Lilian Chen, MD runs the colon and rectal surgery department at Tufts Medical Center. She says the best test is simply the one you actually do. Consistency beats perfection every time.
The slow burn
Polyps usually take 10 to 15 minutes… wait, 10 to 15 years.
They grow silently. Then they turn malignant. Screening interrupts this process. Doctors find the trouble spots before they become tumors. Dr. Tiago Biachi, a medical oncologist at Moffitt Cancer Center, notes that survival rates are excellent when caught early.
Until recently, patients over 45 had two main paths: invasive colonoscopies or home-based stool tests. The ACS has added a third door.
The best screening test is ultimately the one you do consistently.
Here is the breakdown of your options.
The menu of tests
Imaging Studies
– Colonoscopy. Looks at the whole colon. Do it every 10 years.
– Flexible sigmoidoscopy. Checks the lower third. Do it every five years.
– CT colonography. Creates 3D images. Do it every five years
Stool Tests
These are decent. High sensitivity for cancer. Moderate sensitivity for pre-cancer.
- Cologuard : Looks for DNA markers and hemoglobin. Do it every three years
- ColoSense : The newer RNA version. Also looks for hemoglobin. Every three years
- gFOBT : Hidden blood in stool. Do it annually
- FIT : Detects blood in the lower digestive tract. Do it annually
Blood Tests
Here is the trade-off. The Shield Test looks for DNA floating freely in your blood.
It misses more. Less likely to spot stage 1 cancers or advanced polyps compared to stool tests.
The ACS says this test is for people who decline the others. It is the fallback. Do it every three years.
Any positive result? You go to colonoscopy. Within six months. There is no avoiding the scope if the screen turns red.
Who is dying younger?
The overall rate of colorectal cancer is dropping. By 1% annually from 2013 to 2022.
Look closer though.
Among adults 20 to 65? The opposite is true. Cases are rising. By 3% a year.
Three quarters of cancers in under-50s are already advanced by diagnosis. Late stage. Hard to treat. Likely fatal.
“Less than 20% of adults aged 45-49 were up-to-date in 2021.” Biachi says this statistic worries him. About one in five new cancers is now found in people under 55. It has usurped other killers to become the leading cause of death for that group.
Why?
Obesity. Less movement. Processed meats. Fiber-starved diets. Alcohol. Changes in gut bacteria.
Many young patients have no family history. They do not expect the news. This makes the guidelines shift even more necessary.
Ketan Thanki, a colorectal surgeon in California, points out the logistics. Colonoscopies cost money. They eat up a work week. The prep is… unpleasant. People fear complications.
Blood and stool tests bypass that dread. They remove the barrier of inconvenience.
Is the blood test better?
No.
Doctors remain firm. The colonoscopy is the gold standard.
“It detects lesions. Identifies them. Removes them.” Dr. Thanki argues this preventive capability is unmatched. Other tests find cancer; the colonoscopy prevents it by removing the polyps first.
Biachi recommends colonoscopy every ten years for most healthy people starting at 45. Maximum protection.
Blood tests cannot remove anything. They cannot tell the type of lesion.
Thanki ranks Cologuard as his second choice. Blood tests are last. They are best for later stages. They miss the early warning signs.
But maybe you have skipped screenings for years.
Biachi sees blood tests as an entry-level option. A way back in.
“The right choice depends on your personality,” he says. Value convenience. Or value effectiveness. Both have weight.
If you are over 45.
If you haven’t started.
Talk to your doctor. Soon. It matters.
