What's in this article?
- 1 Colon cancer facts
- 2 Risk of developing colon cancer
- 3 Causes of colon cancer
- 4 Symptoms of colon cancer
- 5 Treatment for colon cancer
The colon is another term for the large intestine, it is the lowest part of the digestive system. Inside the colon, water and salt from solid wastes are extracted before the waste moves through the rectum and exits the body through the anus.
Most cases of colon cancer begin as small, noncancerous (benign) clumps of cells called adenomatous polyps. Over time some of these polyps become colon cancers.
Polyps may be small and produce few, if any, symptoms. For this reason, doctors recommend regular screening tests to help prevent colon cancer by identifying and removing polyps before they become colon cancer.
Colon cancer facts
- Colorectal cancer is a malignant tumor arising from the inner wall of the large intestine (colon) or rectum.
- Colorectal cancer is the third leading cause of cancer in both men and women in the U.S.
- Common risk factors for colorectal cancer include increasing age, African-American race, a family history of colorectal cancer, colon polyps, and long-standing ulcerative colitis.
- Most colorectal cancers develop from polyps. Removal of colon polyps can aid in the prevention of colorectal cancer.
- Colon polyps and early cancer may have no early signs or symptoms. Therefore, regular colorectal cancer screening is important.
- Diagnosis of colorectal cancer can be made by sigmoidoscopy or by colonoscopy with biopsy confirmation of cancerous tissue.
- Treatment of colorectal cancer depends on the location, size, and extent of cancer spread, as well as the health of the patient.
- Surgery is the most common medical treatment for colorectal cancer.
- Early-stage colorectal cancers are typically treatable by surgery alone.
- Chemotherapy can extend life and improve quality of life for those who have had or are living
Risk of developing colon cancer
Anything that increases your chance of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. Talk to your doctor if you think you may be at risk for colorectal cancer.
Risk factors for colorectal cancer include the following:
- Having a family history of colon or rectal cancer in a first-degree relative (parent, sibling, or child).
- Having a personal history of cancer of the colon, rectum, or ovary.
- Having a personal history of high-risk adenomas (colorectal polyps that are 1 centimeter or larger in size or that have cellsthat look abnormal under a microscope).
- Having inherited changes in certain genes that increase the risk of familial adenomatous polyposis (FAP) or Lynch syndrome(hereditary nonpolyposis colorectal cancer).
- Having a personal history of chronic ulcerative colitis or Crohn disease for 8 years or more.
- Having three or more alcoholic drinks per day.
- Smoking cigarettes.
- Being black.
- Being obese.
Older age is a main risk factor for most cancers. The chance of getting cancer increases as you get older.
Causes of colon cancer
Normal cells in the body follow an orderly path of growth, division, and death. Cancer is ultimately the result of cells that uncontrollably grow and do not die.
Programmed cell death is called apoptosis, and when this process breaks down cancer results. Colon cancer cells do not die in the normal way, but instead, continue to grow and divide.
Symptoms of colon cancer
Signs and symptoms of colon cancer include:
- A change in your bowel habits, including diarrhea or constipation or a change in the consistency of your stool, that lasts longer than four weeks
- Rectal bleeding or blood in your stool
- Persistent abdominal discomfort, such as cramps, gas or pain
- A feeling that your bowel doesn’t empty completely
- Weakness or fatigue
- Unexplained weight loss
Many people with colon cancer experience no symptoms in the early stages of the disease. When symptoms appear, they’ll likely vary, depending on the cancer’s size and location in your large intestine.
Treatment for colon cancer
The type of treatment your doctor recommends will depend largely on the stage of your cancer. The three primary treatment options are surgery, chemotherapy and radiation.
Surgery for early-stage colon cancer
If your colon cancer is very small, your doctor may recommend a minimally invasive approach to surgery, such as:
- Removing polyps during colonoscopy. If your cancer is small, localized in a polyp and in a very early stage, your doctor may be able to remove it completely during a colonoscopy.
- Endoscopic mucosal resection. Removing larger polyps may require also taking a small amount of the lining of the colon in a procedure called endoscopic mucosal resection.
- Minimally invasive surgery. Polyps that can’t be removed during colonoscopy may be removed using laparoscopic surgery. In this procedure, your surgeon performs the operation through several small incisions in your abdominal wall, inserting instruments with attached cameras that display your colon on a video monitor. The surgeon may also take samples from lymph nodes in the area where the cancer is located.
Surgery for invasive colon cancer
If your colon cancer has grown into or through your colon, your surgeon may recommend:
- Partial colectomy. During this procedure, the surgeon removes the part of your colon that contains the cancer, along with a margin of normal tissue on either side of the cancer. Your surgeon is often able to reconnect the healthy portions of your colon or rectum.
- Surgery to create a way for waste to leave your body. When it’s not possible to reconnect the healthy portions of your colon or rectum, you may need to have a permanent or temporary colostomy. This involves creating an opening in the wall of your abdomen from a portion of the remaining bowel for the elimination of body waste into a special bag.Sometimes the colostomy is only temporary, allowing your colon or rectum time to heal after surgery. In some cases, however, the colostomy may be permanent.
- Lymph node removal. Nearby lymph nodes are usually also removed during colon cancer surgery and tested for cancer.
Surgery for advanced cancer
If your cancer is very advanced or your overall health very poor, your surgeon may recommend an operation to relieve a blockage of your colon or other conditions in order to improve your symptoms. This surgery isn’t done to cure cancer, but instead to relieve signs and symptoms, such as bleeding and pain.
In specific cases where the cancer has spread only to the liver and if your overall health is otherwise good, your doctor may recommend surgery to remove the cancerous lesion from your liver. Chemotherapy may be used before or after this type of surgery. This treatment may improve your prognosis.
Chemotherapy uses drugs to destroy cancer cells. Chemotherapy for colon cancer is usually given after surgery if the cancer has spread to the lymph nodes. In this way, chemotherapy may help reduce the risk of cancer recurrence. Chemotherapy may be used before surgery to shrink the cancer before an operation.
Chemotherapy can also be given to relieve symptoms of colon cancer that has spread to other areas of the body.
In people with rectal cancer, chemotherapy is typically used along with radiation therapy. This combination is often used before and after surgery.
Radiation therapy uses powerful energy sources, such as X-rays, to kill cancer cells that might remain after surgery, to shrink large tumors before an operation so that they can be removed more easily, or to relieve symptoms of colon cancer and rectal cancer.
Radiation therapy is rarely used in early-stage colon cancer, but is a routine part of treating rectal cancer, especially if the cancer has penetrated through the wall of the rectum or traveled to nearby lymph nodes. Radiation therapy, usually combined with chemotherapy, may be used before surgery in order to make the operation easier and to reduce the chance that an ostomy will be necessary. It can also be used after surgery to reduce the risk that the cancer may recur in the area of the rectum where it began.
Targeted drug therapy
Drugs that target specific defects that allow cancer cells to grow are available to people with advanced colon cancer, including:
- Bevacizumab (Avastin)
- Cetuximab (Erbitux)
- Panitumumab (Vectibix)
- Ramucirumab (Cyramza)
- Regorafenib (Stivarga)
- Ziv-aflibercept (Zaltrap)
Targeted drugs can be given along with chemotherapy or alone. Targeted drugs are typically reserved for people with advanced colon cancer.
Some people are helped by targeted drugs, while others are not. Researchers are working to determine who is most likely to benefit from targeted drugs. Until then, doctors carefully weigh the limited benefit of targeted drugs against the risk of side effects and the expensive cost when deciding whether to use these treatments.
Supportive (palliative) care
Palliative care is specialized medical care that focuses on providing relief from pain and other symptoms of a serious illness. Palliative care specialists work with you, your family and your other doctors to provide an extra layer of support that complements your ongoing care.
When palliative care is used along with all of the other appropriate treatments, people with cancer may feel better and live longer.
Palliative care is provided by a team of doctors, nurses and other specially trained professionals. Palliative care teams aim to improve the quality of life for people with cancer and their families. This form of care is offered alongside curative or other treatments you may be receiving.
No complementary or alternative treatments have been found to cure colon cancer.
Alternative treatments may help you cope with a diagnosis of colon cancer. Nearly all people with cancer experience some distress. Common signs and symptoms of distress after your diagnosis might include sadness, anger, difficulty concentrating, difficulty sleeping and loss of appetite. Alternative treatments may help redirect your thoughts, at least temporarily, to give you some relief.
Alternative treatments that may help relieve distress include:
- Art therapy
- Dance or movement therapy
- Music therapy
- Relaxation exercises
Your doctor can refer you to professionals who can help you learn about and try these alternative treatments. Tell your doctor if you’re experiencing distress.