COLON CANCER – CONDITION

The final portions of the tube that extends from the mouth to the anus are the colon and the rectum. Food travels through the oesophagus and into the stomach. It is then grounded into smaller particles and enters the small intestine. This is where final digestion of food and absorption of the nutrients contained in the food occurs. Food that is not digested enters the large intestine (colon) and finally the rectum.

WHAT DOES THE COLON DO?

The large intestine (colon) is about six feet long and acts primarily as a storage facility for waste. Additional water, salts, and some vitamins are further removed. Furthermore, nutrients from the undigested food may be processed by colonic bacteria and is then absorbed by the colon and body. An estimated of ten percent of the energy derived from food comes from these products of bacterial digestion in the colon.

The colon stores the remaining undigested food, dying cells from the lining of the intestines and large numbers of bacteria before periodically passing them into the rectum. When they reach the rectum, a bowel movement is initiated to empty the colonic contents from the body as stool.

WHAT IS COLON CANCER?

Colon CancerIt is the cancer of the large intestine (colon), the lower part of your digestive system. Rectal cancer on the other hand is cancer of the last several inches of the colon. It is often referred to as colorectal cancers when both are affected by cancer.

In most cases, colon cancer starts as small benign clumps of cells called adenomatous polyps. Over time some of these polyps become colon cancers.

It is recommended to get regular screening tests done to prevent colon cancer as the polyps may produce few, if any, symptoms.

SYMPTOMS OF COLON CANCER

In the early stages of colon cancer, most people do not experience any symptoms. When the signs and symptoms do appear, they’ll likely vary depending of the cancer’s size and location in your colon. The signs and symptoms of colon cancer are:

  • Changes in your bowel habits (diarrhea or constipation or a change in the consistency of your stool that lasts longer than four weeks)
  • Rectal bleeding
  • Blood in your stool
  • Persistent abdominal discomfort (cramps, gas or pain)
  • A feeling that your bowel doesn’t empty completely
  • Weakness or fatigue
  • Unexplained weight loss

TREATMENT OPTIONS FOR COLON CANCER

The type of treatment will depend largely on the stage of your cancer. Surgery, chemotherapy and radiation are the three primary options:

  • Surgery for early-stage colon cancer:If your colon cancer is small and in the early stages, your doctor may recommend a minimally invasive approach to surgery, such as:
  • Removing polyps during colonoscopy:It may be completely removed during a colonoscopy if it is small, localized and in an early stage.
  • Endoscopic mucosal resection: Taking a small amount of the lining of the colon to remove larger polyps.
  • Minimally invasive surgery: Laparoscopic surgery may be used to remove polyps that can’t be removed with colonoscopy. Several small incisions will be made in your abdominal wall. Instruments with attached cameras that display your colon on a video monitor will be inserted to give your surgeon a better view. Biopsy samples from lymph nodes in the area where the cancer is located may also be taken.
  • Surgery for invasive colon cancer:If your colon cancer has grown into or through your colon, your surgeon may recommend:
  • Partial colectomy: 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. The healthy portions of your colon or rectum can normally be reconnected.
  • 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, permanent or temporary colostomy may be required. An opening is made in the wall of your abdomen from a portion of the remaining bowel for the elimination of body waste into a special bag. Sometimes, colostomy is only temporary. This is to allow your colon or rectum time to heal after surgery.
  • Lymph node removal: Nearby lymph nodes are also normally removed during colon cancer surgery and tested for cancer.
  • Surgery for advanced cancer:If your overall health is poor and your cancer is very advanced, an operation may be recommended 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 cases where your overall health is good but you have colon cancer that has spread only to the liver, surgery may be recommended 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: Drugs are used  to destroy cancer cells. This treatment is normally used after surgery if the cancer has spread to the lymph nodes. It may help to reduce the risk of cancer recurrence. It may be used before surgery to help reduce the size of the cancer. It can also be given to relieve symptoms of colon cancer that has spread to other areas of the body. For people with rectal cancer, chemotherapy is normally used along with radiation therapy before and after surgery.
  • Radiation therapy: Powerful energy sources such as X-rays are used to kill cancer cells and shrink large tumors before an operation so that they can be easily removed or to relieve symptoms of colon cancer and rectal cancer. This therapy is rarely used in early-stage colon cancer. However, it is a routine part of treating rectal cancer, especially if the cancer has spread through the wall of the rectum or traveled to nearby lymph nodes. Combined treatment of radiation therapy and chemotherapy may be used before surgery in order to make the operation easier and to decrease the chance that an ostomy will be necessary. It may also be used after surgery to reduce the risk of recurrence.
  • Targeted drug therapy:Drugs that target specific defects that promotes cancer growth 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 alone or with chemotherapy. They are typically reserved for people with advanced colon cancer. It may help some people, while others are not helped by the drugs. Researchers are working to determine who is most likely to benefit from targeted drugs. Until then, doctors will carefully weigh the limited benefit of targeted drugs against the risk of side effects and the expensive cost.

PARTIAL COLECTOMY (COLON CANCER)

DIAGNOSTIC SERVICES AVAILABLE FOR COLON CANCER DETECTION

  • History taking and physical examination:Your doctor will ask you questions about your overall health, symptoms you have and family medical history, as those, who have a family history of colon cancers are assumed to be more predisposed to have the same condition. Then your doctor will perform a physical examination of your body to look for any visible symptoms.
  • Blood tests: Colon cancer can’t be detected through blood tests. However, blood tests may be performed for clues about your overall health, such as kidney and liver function tests. A blood test may be done to check for a chemical sometimes produced by colon cancers (carcinoembryonic antigen or CEA). Monitored over time, the level of CEA in your blood may allow your doctor to understand your prognosis and whether your cancer is responding to treatment.
  • Colonoscopy: This test allows your doctor to look at the inner lining of your large intestines. A thin, flexible tube called a colonoscope is used to look at the colon.  This is the most sensitive test for colorectal polyps and cancer. If polyps are found, they may be removed immediately or biopsy samples may be taken for analysis.