Colon Cancer: Causes, Risk Factors, Symptoms, Diagnosis, Treatment and Prevention

Also called colorectal cancer, it is cancer that begins in the large intestine (colon) or rectum (end of the colon).


In the United States, colorectal cancer is one of the leading causes of cancer death. Early diagnosis can often lead to a complete cure. Almost all types of colon cancer begin in the lining of the colon and rectum.

There is not a single cause of colon cancer. Almost all types of colon cancer begin as non-cancerous (benign) polyps, which slowly turn into cancer.

Risk factor’s

You have an increased risk of colon cancer if:

  • He is over 60 years old.
  • He is African American or a descendant of Eastern Europe.
  • Eat many red or processed meats
  • It has colorectal polyps.
  • You have inflammatory bowel disease ( Crohn’s disease or ulcerative colitis ).
  • Have a family history of colon cancer.

Some inherited diseases also increase the risk of developing colon cancer. One of the most common is the adenomatous polyposis family (FAP in English). What you eat may play a role in colon cancer.

Colon cancer can be related to a diet high in fat and low in fiber and increased consumption of red meat. Some studies have found that the risk does not decrease if you switch to a high fiber diet, so this link is not yet clear.

Cigarette smoking and drinking alcohol are other risk factors for colorectal cancer.



Many cases of colon cancer have no symptoms. However, if there are symptoms, the following may indicate colon cancer:

  • Abdominal pain and tenderness in the lower abdomen.
  • Blood in the stool.
  • Diarrhea, constipation, or other change in bowel habits.
  • Narrow stools
  • Weight loss without a known reason.


Through screening tests, colon cancer can be detected before symptoms appear. This is when cancer is more curable. Your doctor will perform a physical exam and press your abdominal area. It is rare for the physical examination to show any problem, although the doctor may feel a lump (mass) in the abdomen.

A rectal exam can reveal a mass in people with rectal cancer, but not colon cancer. A fecal occult blood test (FOBT) can detect small amounts of blood in the stool. This may suggest colon cancer.

A sigmoidoscopy, or more likely a colonoscopy, will be done to evaluate the cause of the blood in the stool. Only a complete colonoscopy can see the entire colon. This is the best screening test for colon cancer.

Blood tests may be done for people diagnosed with colorectal cancer, including:

  • Complete blood count (CBC) to detect anemia.
  • Liver function tests: More tests will be done to see if cancer has spread if you are diagnosed with colorectal cancer.
  • CT scans or MRI scans of the abdomen, pelvic area, or chest can be used to evaluate the stage of cancer. Sometimes, PET scans are also used.

The stages of colon cancer are:

  • Stage 0: very early cancer in the innermost layer of the intestine.
  • Stage I: Cancer is found in the inner layers of the colon.
  • Stage II: Cancer has spread through the muscle wall of the colon.
  • Stage III: cancer has spread to the lymph nodes.
  • Stage IV: cancer has spread to other organs outside the colon.

Blood tests to detect tumor markers, such as carcinoembryonic antigen (CEA), can help the doctor follow it during and after treatment.


Treatment depends on many things, including the cancer stage. Treatments may include:

  • Surgery to remove the tumor.
  • Chemotherapy to kill cancer cells.
  • Radiation therapy destroys cancerous tissue.
  • Targeted therapy to prevent cancer from growing and spreading.


Zero-stage colon cancer can be treated by removing the tumor. This is often done using a colonoscopy. For stages I, II, and III of cancer, more extensive surgery are needed to remove the cancerous part of the colon. This surgery is called colectomy.


In the third stage, almost all people with colon cancer are treated with chemotherapy after surgery for 6 to 8 months. This is called adjuvant chemotherapy. Although the tumor was removed, chemotherapy is given to treat any cancer cells that may remain.

Chemotherapy is also used to improve symptoms and prolong survival in people with stage IV colon cancer. You may receive only one type of medication or a combination of drugs.


Radiation therapy is sometimes used for colon cancer. Liver-directed treatment may be used for people with stage IV disease that has spread to the liver. This may include:

  • Burning cancer (ablation).
  • Administration of chemotherapy or radiation directly in the liver.
  • Freeze cancer ( cryotherapy ).
  • Surgery.

Objectives of therapy

The applied treatment focuses on specific targets (molecules) in the cancer cells. These targets play a role in how cancer cells grow and survive.

The drug deactivates the cancer cells by using these targets so they do not spread. Targeted therapy can be given as pills or injected into a vein. You may have targeted therapy and surgery, chemotherapy, or radiation therapy.

You can relieve the stress of the disease by joining a support group for colon cancer. Sharing with others who have experiences and problems in common can help you not feel alone.

In many cases, colon cancer is treatable when detected early.

Efficacy depends on many things, especially the cancer stage. Many people survive at least five years after diagnosis when treated at an early scene; many survive at least five years after diagnosis. This is called the 5-year survival rate. It is considered cured if colon cancer does not return (recur) within five years.

Stage I, II, and III cancers are considered possibly curable. ALTHOUGH THERE ARE EXCEPTIONS, stage IV cancer is not regarded as curable in most cases.


Complications may include:

  • Obstruction of the colon, causing intestinal obstruction.
  • Cancer returning in the colon.
  • Cancer spreads to other organs or tissues (metastasis).
  • Development of a second primary colorectal cancer.

When to call the doctor?

  • Black stools like tar.
  • Blood during a bowel movement
  • Change in bowel habits.
  • Unexplained weight loss


Colon cancer can almost always be contracted by colonoscopy in its earliest and most curable stages. Nearly all men and women 50 and older should have a colon cancer screening.

People at higher risk may need earlier evaluations. Colon cancer screening can often find polyps before they become cancerous. The removal of these polyps can prevent colon cancer.

Changing your diet and your lifestyle is essential. Medical research suggests that diets low in fat and high in fiber may reduce your risk of colon cancer.

Some studies have reported that NSAIDs (aspirin, ibuprofen, naproxen, and celecoxib) may help reduce the risk of colorectal cancer. However, these medications can increase your risk of bleeding and heart problems.

Your provider can give you more information about the risks and benefits of medications and other ways that help prevent colorectal cancer. Colon or colorectal cancer begins in the large intestine (colon) or rectum (end of the colon).