Updated: October 29, 2019
The human colon or large intestine is a muscular, tube shaped organ of about 4 feet long. It extends from the end of the small bowel to the rectum. Typically, the structure of the colon consist of four parts. First or right portion of the colon is called the ascending colon moves up from the lower right portion of the abdomen. The next portion, or transverse colon, moves across from the right to the left side of the upper abdomen. Next, the third region or descending colon moves down the left side of your abdomen. Then an S shaped or sigmoid colon portion of the large intestine connects the rest of the colon to the rectum, which ends at the anus.
The right side of your colon plays a major role in absorbing water and electrolytes, while the left side is responsible for storage and evacuation of stool.
Cancer is the transformation of normal cells. The transformed cells grow and multiply abnormally when DNA of a cell is damaged and becomes cancerous.
Colon cancer is cancer of the colon or large intestine. These cancer cell grow and eventually spread through the colon wall to involve the adjacent lymph nodes and organs. Ultimately, they spread or metastasized to distant organs such as the liver, lungs, brain, and bones. Because of their uncontrolled growth and potential for spread, cancers are dangerous . They overwhelm healthy cells, tissues, and organs by taking their oxygen, nutrients, and space.
Most colon cancers are adenocarcinomas tumors that develop from the glands lining the inner wall of colon. The rectum, the end portion of the colon, can also be affected, but these areas be separately recognized by many investigators.
The type of treatment recommended by your doctor will depend on the type and stage of the cancer. The age, health status, and other characteristics of the patient will also be taken in to consideration while deciding a treatment plan. There is no single treatment for any cancer, but the most common options for colon cancer are surgery, chemotherapy, and radiation therapy.
The goal of any type of treatment is to remove the cancer and relieve any painful symptoms. These include:
Surgery are of many types depending on the stage of cancer. These can be:
Your doctor may recommend a minimally invasive approach to surgery if your colon cancer is very small, such as:
Your doctor may be able to remove the cancer completely during a colonoscopy, if your cancer is small, localized and completely contained within a polyp and in a very early stage.
It may also require taking a small amount of the lining of the colon or rectum while removing larger polyps in this procedure.
Polyps that can't be removed during a colonoscopy may be removed using laparoscopic surgery. In this procedure, instruments with attached cameras that display your colon on a video monitor will be inserted and your surgeon performs the operation through several small incisions in your abdominal wall.
The surgeon may also take samples from lymph nodes in the area where the cancer is located for biopsy.
The below procedures are recommended if the cancer has grown into or through your colon.
The part of your colon that contains the cancer, along with a margin of normal tissue on either side of the cancer will be removed by the surgeon during this procedure. Your surgeon is often able to reconnect the healthy portions of your colon or rectum. This procedure can commonly be done by a minimally invasive approach called laparoscopy.
When it is not possible to reconnect the healthy portions of your colon or rectum, you may need an colostomy. This involves creating an opening in the wall of your abdomen from a portion of the remaining bowel for the elimination of stool into a bag that fits securely over the opening. Fecal matter will exit your body through this hole instead of through your anus. A small appliance or bag, which attaches to your skin around the opening and collects fecal matter. The bag is changed regularly to prevent skin irritation and odor. Your surgeon will attempt to preserve your rectum and anus in best possible ways. It is now possible in several surgical procedures to preserve evacuation of fecal material through the anus.
Sometimes the colostomy is only temporary, allowing your colon or rectum time to heal after surgery. However, in some cases the colostomy may be permanent. In general, tumors on the right side of your colon or on the left side above the level of the rectum may not qualify for colostomy.
Tumors in the rectum may require removal of the rectum and anal sphincter and construction of a permanent colostomy to divert your bowel.
Nearby lymph nodes are usually also removed during colon cancer surgery and tested for cancer.
Your surgeon may recommend an operation to relieve a blockage of your colon or other conditions in order to improve your symptoms if your cancer is very advanced or your overall health is very poor. This surgery is known as Palliative surgery. It can not cure cancer, but instead relieve signs and symptoms, such as bleeding and pain. Surgery to remove the cancerous lesion from your liver may recommended by your doctor if the cancer has spread only to the liver but your overall health is otherwise good.
Chemotherapy may be used before or after this type of surgery. A chance to be free of cancer over the long term is provided by this approach.
Chemotherapy uses chemicals that interfere with the cell division process by damaging proteins or DNA in order to damage and kill cancer cells.
The rapidly dividing cells, including healthy ones are targeted in these treatments. The healthy cells can usually recover from any chemically induced damage, but cancer cells cannot.
Chemotherapy for colon cancer is usually given after surgery if the cancer has spread to lymph nodes as the medicines travel through the whole body. This way, chemotherapy may help reduce the risk of cancer recurrence and death from cancer. Sometimes chemotherapy may be used before surgery as well to shrink the tumor. Chemotherapy before surgery is more common in rectal cancer than in colon cancer.
Chemotherapy can also be given to relieve symptoms of colon cancer that has spread to other areas of the body in advanced stage. Treatment occurs in cycles, so the body has time to heal between doses. Hair loss, nausea, fatigue and vomiting are the most common side effects. To reduce these side effects combination therapies are often used which involve mixing multiple types of chemotherapy or combining chemotherapy with other treatments.
Radiation therapy damages and kills cancer cells by focusing high energy gamma rays on them. Radioactive gamma rays are emitted from metals such as radium, or from high energy x-rays. Radiotherapy can be used as a standalone treatment to shrink a tumor before an operation so that they can be removed more easily or destroy cancer cells. It can also be used alongside other cancer treatments to to relieve symptoms of colon cancer and rectal cancer.
Radiation treatments are used if early stage rectal cancer has penetrated the wall of the rectum or traveled to nearby lymph nodes. This is one of the standard treatment options for the initial management of rectal cancer followed by surgery.
Mild skin changes resembling sunburn or suntan, nausea, vomiting, diarrhea, fatigue, appetite and weight loss are common side effects of radiation therapy. Most side effects resolve a few weeks after completing treatment.
Drugs are available that target specific malfunctions which allow cancer cells to grow in advanced colon cancer. These include:
Targeted drugs can be given along with chemotherapy or alone. These are typically reserved for people with advanced colon cancer. The possible benefit of targeted drugs against the risk of side effects and the cost must be evaluated when deciding whether to use these treatments.
Immunotherapy with antibodies such as pembrolizumab (Keytruda) and nivolumab (Opdivo) can be used for some patients with advanced colon cancer. Whether a colon cancer has the chance to respond to these immunotherapies can be determined by a specific test of the tumor tissue.
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. Palliative care can be used along with aggressive treatments, such as surgery, chemotherapy and radiation therapy. People with cancer may feel better and live longer when palliative care is used along with other appropriate treatments . This can be used soon after diagnosing the disease.
Follow-up visits to gastroenterologist or cancer specialist (oncologist) should be regular once your cancerous colon has been removed and you receive any other treatment recommended by your cancer care team. These visits will allow your team to see if the cancer has spread and to detect newly formed cancers.
These follow-up visits should include:
An immunochemical screening tool measurement of carcinoembryonic antigen (CEA) level is available to test for cancer recurrence following cancer surgery.
If you develop new severe health problems that would make you unfit to undergo treatment for a recurrence of your colon cancer, then you should discontinue screening tests.
Recovery from colon cancer depends on the extent of your disease before your surgery. There is a 92 percent chance of surviving at least another 5 years if the cancer is detected in initial stage. At stage 4, the percentage is 11 percent.
If your tumor is limited to the inner layers of your colon, you can expect to live five years or more without cancer recurrence. But this is again depending on how deeply the cancer was found to invade into the wall.
As symptoms may not appear until the cancer has progressed, annual screening is recommended for men and women aged 50 to 75 years. Colonoscopy is suggested for early detection of colon cancer, as it is the most accurate method. It visualizes the entire colon and allows the surgeon to remove polyps during the procedure.
Other recommended screening tests include:
These frequency recommendations depend on the individual's risk of colon cancer.
Living with cancer have many new challenges, both for you and for your family and friends. How the cancer will affect you and your ability to live a normal life would be the main concern. A mixed reaction is found with these patients. Many people feel anxious and depressed. Some people feel angry and resentful where as others feel helpless and defeated.
For most people with cancer, It helps talking about their feelings and concerns to others. Your friends and family members can be very supportive. They may be hesitant to offer support until they see how you are coping. so don't wait for them to bring it up. Let them know if you want to talk about your concerns. If you prefer talking your concerns with a more neutral professional, a social worker, counselor, or member of the clergy can be helpful. If you want to discuss your feelings and concerns about having cancer, your primary care doctor or oncologist should be able to recommend someone.
Sharing your concerns with others who have been through the same thing can be remarkably reassuring. Support groups of people with cancer may be available through the medical center where you are receiving your treatment.
For more information about support groups, contact the following agencies:
American Cancer Society - (800) ACS-2345
National Cancer Institute, Cancer Information Service - (800) 4-CANCER [(800) 422-6237)], TTY (for deaf and hard of hearing callers) (800) 332-8615