Colon Cancer Facts

The colon and rectum form a long, muscular tube called the large intestine or large bowel. The colon is the upper five to six feet of the large bowel, and the rectum is the last six to eight inches. The large bowel, along with the esophagus, stomach, and the small bowel, is a part of the body’s digestive system. The digestive system absorbs minerals, proteins, and vitamins from food eaten and stores the waste until it passes out of the body.

Tumors can begin anywhere in the colon or rectum. Sometimes a benign growth, called a polyp, may start to grow on the wall of the colon or rectum. Polyps in the colon or rectum can become cancerous so they should be removed. These can be easily removed in a doctor’s office during an examination using a lighted flexible tube. If not removed, these cancer cells can spread to the nearby lymph nodes or enter into the blood stream. Once cancer cells have entered the bloodstream, the cells can also spread to other parts of the body such as the liver and lungs. People who have had one polyp are more likely to develop others, so it is very important they have regular check-ups to find and take out any polyps before they turn cancerous.

Colorectal cancer –or colon cancer– is the second leading cause of death from cancer in the United States. In 2011, 131,607 people in the United States were diagnosed with colorectal cancer and 52.045 people died from it . Like most health problems, colorectal cancer responds best to treatment when it is diagnosed and treated as early as possible, especially before it has a chance to spread outside of the colon.

Risk Factors of Colon Cancer

Studies have found that certain things may increase a person’s risk of getting colorectal cancer. These include:

  • Being age 50 or older.
  • Previously having colon polyps (small non cancerous growths).
  • A family history of colon cancer.
  • Personal history of colon, rectum, ovary, endometrium or breast cancer.
  • Having inflammatory bowel disease such as ulcerative colitis or Crohn’s disease.
  • Hereditary conditions like familial adenomatous polyposis or hereditary nonpolyposis colon cancer (HNPCC; Lynch Syndrome).
  • Eating a high fat, low fiber diet.
  • Being African American and Ashkenazi Jew populations.
  • Being obesity, smoking, alcohol intake and an inactive way of life.

Symptoms of Colon Cancer

Colorectal cancer can cause a wide range of symptoms. Warning signs to watch for include:

  • Change in usual bowel habits (i.e. used to have one bowel movement a day, now having 2-3 movements a day)
  • Blood in the stool, either dark red or bright red
  • Fatigue or tiredness
  • Stools that are more narrow than usual
  • Abdominal pain or discomfort such as gas pains, cramping, bloating or a feeling of fullness
  • Loose or watery bowel movements or hard, difficult to pass stools, that continue for over two weeks
  • Feeling as if bowel does not empty completely
  • Weight loss for no reason

These same symptoms may be caused by problems other than cancer. Only a doctor can find out the cause. If you have any of these symptoms you should see your doctor.

Colon Cancer Prevention Tips

There are steps you can take to help prevent colorectal cancer:

  • Eat a diet high in fiber and/or fruits and vegetables. It is not known if a diet low in fat and high in fiber, fruits and vegetables lowers the risk of colon and rectal cancers but some studies have shown that a diet high in protein, fat, calories and meat increases the risk of colorectal cancer.
  • Increase your activity level.

Research has connected an inactive lifestyle with a higher risk of colon and rectal cancer. A person is considered physically active if they exercise for at least 30 minutes a day.

  • Limit your alcohol intake.

Drinking more than one drink daily for women and two drinks daily for men has been shown to raise the risk of mouth, esophagus, pharynx, larynx, and liver cancers in both women and men, and breast cancer in women. Heavy alcohol use has been shown to increase the risk of colorectal cancer.

  • Have regular screening examinations.

Screening exams can find and remove precancerous polyps before they turn into cancer. Follow your doctor’s advice about having tests for colon cancer.

Colon Cancer Screening

You can take an active role in the prevention and early detection of colorectal cancer by getting tested regularly after the age of 50. Talk to your doctor about which test you should have.

These tests are commonly used to screen for colorectal cancer:

Digital Rectal Exam (DRE)
A doctor inserts a gloved and lubricated finger into the rectum to feel for lumps or other abnormal areas. It is used as the first method of detection for rectal cancer.
Fecal Occult Blood Test (FOBT)
A test to see if there is hidden blood in the stool. A positive result may be a sign of cancer or polyps.
Barium enema
An x-ray of the entire lower bowel using barium solution that is given through the rectum. This test can find polyps, cancer, colitis, and diverticulosis. Before the examination, laxatives and regular enemas are used to clean the bowel.
Sigmoidoscopy
An examination of the rectum and lower (sigmoid) colon with a hollow lighted tube. It is used to find colon polyps, cancer, and/or to find the cause of bleeding. Tissue can be removed for a doctor to look at under a microscope to make a diagnosis. Before the test, laxatives are used to clean the bowel.
Colonoscopy
A test that looks in the rectum and entire colon by using a long fiber optic telescope that is lighted and flexible. It may reveal polyps, cancer, colitis, and diverticulosis. Tissue can be removed for a doctor to look at under a microscope to make a diagnosis. May require sedation. Before the test, laxatives must be used to clean the bowel.
Virtual colonoscopy (also called CT colonoscopy)
A CT (computerized tomography) scan creates cross section images of the body, which may show cancer or its spread to other organs. Before the test, laxatives must be used to clean the bowel.
DNA Stool test
A stool sample is examined for abnormal DNA that may be a sign of colorectal cancer. This technology is still undergoing testing to see if it is more effective at finding cancer cells earlier than other screening options.

Treatment of Colon Cancer

The treatment for colon cancer depends on the stage of the cancer when it is diagnosed. There are three standard or usual treatments used to fight colon cancer: surgery, chemotherapy, and radiation therapy.

Surgery

An operation is done to remove the cancer. It is the most common treatment for all stages of colon cancer. Doctors use several types of operations to remove colon cancer:

  • Local excision—when the cancer is in a very early stage, the doctor can remove it without making a cut or incision on the abdomen. The doctor will put a tube into the colon and cut the cancer out through the tube. If the cancer is found in a polyp the surgery is called a polypectomy.
  • Resection—if the cancer is larger, the doctor will perform a partial colectomy. This means removing the part of the colon where the cancer is and part of healthy tissue surrounding the cancer. The doctor may then do an anastomosis, which is sewing the healthy parts of the colon together. The doctor will usually remove lymph nodes near the colon and examine them under a microscope to see if they contain cancer cells.
  • Resection and colostomy—if the doctor is not able to sew the two ends of colon back together, an opening (stoma) is made on the outside of the body for bowel movements to pass through. This operation is called a colostomy. A bag is connected to the stoma to collect the waste. Colostomies sometimes are needed only until the lower colon has healed, then the colon can be sewn back together. Sometimes, however, a colostomy is permanent.
  • Radiofrequency ablation—a special probe with small electrodes is used to kill cancer cells. The probe is often inserted directly through a cut in the skin and only local anesthesia is needed. If a larger cut is made then general anesthesia is used.
  • Cryosurgery—abnormal tissue is frozen and killed by an instrument. This is also called cryotherapy.

Chemotherapy

Chemotherapy is medicine that can kill cancer cells or stop them from growing. Chemotherapy can be taken in a pill form, it may be given in the vein through an IV, or it may be given in the muscle with a needle. Whichever way it is given, the medicine will travel through the bloodstream and kill cancer cells throughout the entire body. This is called systemic chemotherapy. If the chemotherapy is placed into an organ or a body cavity like the abdomen, the medicine will try to affect only the cancer cells in that area. This is called regional chemotherapy. Most often with colon cancer the term intraperitoneal chemotherapy is used because the medicine is placed in the abdominal (peritoneal) cavity using a thin tube.

Chemoembolization

This is for patients whose colon cancer has spread to the liver. Doctors block the artery that feeds the liver with blood and inject chemotherapy drugs into the artery, in between the blockage and the liver so the drugs will go directly to the liver. Only a small amount of the chemotherapy will reach other cells.

Radiation therapy

Radiation therapy is the use of x-rays or other types of energy to kill cancer cells or keep them from growing. Usually radiation is given outside the body using a machine (external radiation). Internal radiation uses radioactive substances like needles, seeds, wires, or catheters that are put directly in or near the cancer.

Biological therapy

This is treatment with substances to encourage the body’s own immune system to fight the cancer. It can also be called immunotherapy or biotherapy.

Stages of Colon Cancer

Colon cancer tests will also determine the stage of the cancer. The stage of colon cancer tells how big the tumor is, how deep it is, and if it has spread to another part of the body. The treatment of cancer is given according to the stage of the disease. The stage also gives information on the overall outlook of the cancer– whether it can be cured. The lower the stage, the better the outlook.

Stage 0

The abnormal cells are found in the inner most lining of the colon only. Abnormal cells can become cancerous and spread into the normal tissue. This stage is also called “carcinoma in situ”.

Stage I

The cancer has spread past the inner most tissue layer of the colon wall to the middle layers. Stage I colon cancer is sometimes called “Dukes A colon cancer.”

Stage II

Colon cancer is divided into stage IIA and IIB

  • Stage IIA: Cancer has spread past the middle tissue layers of the colon wall or has spread to nearby tissues around the colon or rectum.
  • Stage IIB: Cancer has spread past the colon wall into nearby organs and/or through the peritoneum.

Stage II colon cancer is sometimes called “Dukes B colon cancer.”

Stage III

Colon cancer is divided into stage IIIA, stage IIIB, and IIIC.

  • Stage IIIA: Cancer has spread from the innermost tissue layer of the colon wall to the middle layers and has spread to as many as three lymph nodes.
  • Stage IIIB: Cancer has spread to as many as three nearby lymph nodes and has spread:
    • past the middle tissue layers of the colon wall; or
    • to nearby tissues around the colon or rectum; or
    • past the colon wall into nearby organs and or through the peritoneum.
     
  • Stage IIIC: Cancer has spread to four or more lymph nodes and has spread:
    •  to or past the middle tissue layers of the colon wall; or
    •  to nearby tissues around the colon or rectum; or
    •  to nearby organs and/or through the peritoneum.
     

Stage III colon cancer is sometimes called “Dukes C colon cancer.”

Stage IV

Cancer has spread to nearby lymph nodes and other parts of the body, such as the liver or lungs. Stage IV colon cancer is sometimes called “Dukes D colon cancer.”

Recurrent colon cancer

Cancer that has recurred (come back) after it has been treated. The cancer may come back in the colon or in other parts of the body, such as the liver, lungs, or both.

Treatment Options by Stage

Stage 0 Colon Cancer (Carcinoma in Situ)

  • Local excision or simple polypectomy (polyp removal).
  • Surgery to cut out the cancer and sew the two ends of colon back together.

Stage I

  • Surgery to cut out the cancer and sew the two ends of colon back together.

Stage II

  • Surgery to cut out the cancer and sew the two ends of colon back together.
  • Clinical trials of chemotherapy, radiation therapy, or biologic therapy after surgery.

Stage III

  • Surgery to cut out the cancer and sew the two ends of colon back together with chemotherapy.
  • Clinical trials of chemotherapy, radiation therapy, and/or biologic therapy after surgery.

Stage IV and Recurrent Colon Cancer

  • Surgery to cut out the cancer and sew the two ends back together to remove or bypass the tumor.
  • Surgery to remove parts of other organs where the cancer may have come back or spread, such as the liver, lungs or ovaries.
  • Clinical trials of chemotherapy and/or biological therapy.
  • Radiation or chemotherapy may be offered to some patients to relieve symptoms and improve their quality of life.

Cancer that has come back or recurred in the original location may be removed by local excision.