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But when symptoms persist or change significantly, medical evaluation becomes important.
What Is Colon Cancer?
Colon cancer develops in the large intestine.Health
The colon absorbs water and electrolytes from digested food and helps form stool.
Most colon cancers begin as abnormal growths called polyps.
Many polyps are harmless.
However, certain types can gradually develop into cancer.
This process generally occurs over years, which is one reason screening can be so valuable.
If a precancerous polyp is discovered during screening, doctors may be able to remove it before it becomes cancerous.
Colon Cancer and Colorectal Cancer
The term “colorectal cancer” includes cancers of both the colon and rectum.
Colon cancer refers specifically to cancer arising in the colon.Cancer
Rectal cancer develops in the rectum.
Because the two conditions share many risk factors and are often screened for together, health information frequently uses the broader term colorectal cancer.
Why Screening Matters
One of the most important facts about colorectal cancer is that screening can detect disease before symptoms appear.
That is significant because early colorectal cancer may not cause noticeable problems.
Screening can identify precancerous polyps or early cancers.
Depending on the screening method and results, a doctor may recommend further testing or removal of suspicious growths.Health Conditions
Screening recommendations vary by country and by individual risk.
People should discuss the appropriate screening schedule with their healthcare professional.
Colonoscopy
Colonoscopy is one of the best-known colorectal cancer screening methods.
During the procedure, a doctor uses a flexible camera to examine the inside of the colon and rectum.
If polyps are found, they can often be removed during the same procedure.
Tissue can then be examined by a pathologist.
Colonoscopy requires preparation beforehand so that the colon can be adequately examined.GERD & Digestive Disorders
Although the preparation can be inconvenient, the procedure provides a detailed examination of the entire colon.
Stool-Based Tests
Some screening programs use stool-based tests.
These tests can look for hidden blood or other changes associated with colorectal cancer.
One common approach is the fecal immunochemical test, or FIT.
A positive stool test does not mean that someone has cancer.
It means that additional evaluation, often including colonoscopy, may be needed to identify the cause.
Stool-based screening can be convenient and is an important option in many screening programs.Anatomy
Who Is at Higher Risk?
Colon cancer risk increases with age, although younger adults can develop it as well.
Other factors associated with increased risk include:
A family history of colorectal cancer
Certain inherited genetic syndromes
A personal history of colorectal polyps
Inflammatory bowel disease
Smoking
Heavy alcohol consumption
Physical inactivity
Obesity
Certain dietary patterns
Biological Sciences
Having one risk factor does not mean that cancer will develop.
Likewise, someone without obvious risk factors can still develop colorectal cancer.
Family History
Family history can be particularly important.
Someone whose parent, sibling, or child has had colorectal cancer may have a higher risk.
The risk can be influenced by the age at which the relative was diagnosed and whether multiple relatives have been affected.
People with a strong family history should discuss it with a doctor because they may need to begin screening earlier or undergo screening more frequently.
Genetic Syndromes
Some inherited conditions significantly increase the risk of colorectal cancer.Medical Tests & Exams
Two important examples are Lynch syndrome and familial adenomatous polyposis.
These conditions are relatively uncommon but can have major implications for affected families.
Genetic counseling and testing may be appropriate when there is a strong family history or a pattern of cancers suggesting an inherited syndrome.
Inflammatory Bowel Disease