Colon Cancer

Colon cancer is known as a cancer of the colon (large intestine), the lower portion of the Gastrointestinal or digestive system. Also, Rectal cancer occurs on the last several inches of the colon. Colon and rectal cancer Together are referred to as colorectal cancers.

Usually, colon cancer starts as a small, noncancerous (benign) clumps of cells, also known as adenomatous polyps. With the passage of time, some of these polyps become colon cancer.Polyps usually produce very fewer symptoms, therefore regular screening tests are performed to identify and remove polyps before they become colon cancer.


In most cases, the reason of causing a colon cancer is not clearly known. However, it is observed that when DNA of healthy colon cells is damaged and becomes cancerous, then these infected cells continue to grow and divide, even when new cells aren’t needed. The growth of these abnormal cells accumulates to form a tumor.

Common risk factors that may increase the risk of colon cancer include:

Old age: People older than 50 are more prone to suffer from colon cancer. However, colon cancer can also occur in younger people much less frequently.

Obesity: Obese or overweight people have more risk of having colon cancer as compared to the normal weight people.

High-fat or Low-fiber diet: Researchers have revealed that a diet low in fiber and high in fat and calories may increase the risk of colorectal cancer. Especially, people who eat high red meat and processed meat diet are more prone to colon cancer.

Alcohol & Smoking: Smokers and alcoholics have an increased risk of colon cancer.

Diabetes: Diabetes and insulin resistance are associated with an increased risk of colon cancer.

Family history: People are more likely to develop colon cancer if their parents, sibling or child also suffering from the disease. If more family members have colon or rectal cancer, the risk may be even greater.

Sedentary lifestyle: people with inactive or sedentary lifestyle are more likely to develop colon cancer. A regular physical activity can overcome a risk of colon cancer.

Geographical race: African-Americans have more risk of having colon cancer than people of other races.

History of colorectal cancer or polyps: If a person already had suffered from colon cancer or adenomatous polyps, then he/she may have a greater chance of having colon cancer in the future.

Inflammatory colon conditions: various chronic inflammatory colon diseases, such as ulcerative colitis and Crohn’s disease, can raise the risk of colon cancer.

Genetic syndromes: Various genetic syndromes, such as Lynch syndrome may travel through generations of a family to increase the risk of colon cancer.

Radiation therapy: Previous radiation therapy to treat cancers directed at the abdomen may enhance the risk of colon cancer.


In the early stages of colon cancer, many people do not experience any symptoms. But once symptoms appear, they’ll likely differ, depending on the cancer’s size and location of cancer in the colon.

Various signs and symptoms of colon cancer may include:

  • Change in bowel habits, including a change in consistency of stool, diarrhea or constipation that lasts more than four weeks
  • Abdominal pain and discomfort, including cramps and gas
  • Blood in your stool or rectal bleeding
  • A feeling of insufficient stomach emptying
  • Unexplained weight loss
  • Weakness or fatigue

Screening for colon cancer

In order to look for initial signs of colon cancer, doctors may conduct certain screening tests in people with no signs or symptoms. The earliest finding of colon cancer has the greatest chance for a cure.

Usually, screening is performed at the beginning of age 50. Especially in people with a family history of colon cancer, screening should be considered at age 45.


Once signs and symptoms indicate chances of colon cancer, then one or more tests procedures may be recommended including:

Colonoscopy: It is performed to examine the inside of the colon. A long, slender, and flexible tube is attached to a video camera to examine entire colon and rectum for any suspicious regions. Once they are found, the doctor can use surgical tools through the tube to take tissue samples for biopsy analysis.

Blood tests: Blood tests, including kidney and liver function tests, are performed to get clues about the overall health of the patient and also test blood for a chemical (carcinoembryonic antigen or CEA. The level of CEA in your blood may help your doctor understand prognosis and how cancer is responding to treatment.

Staging: Once colon cancer is diagnosed, the doctor will suggest more tests to confirm the total age and extent (stage) of cancer. Staging helps a specialist to determine the most appropriate treatment. Staging mainly involves imaging procedures like abdominal or chest CT scans. Many times, the stage of cancer can only determin after colon cancer surgery.


Generally, according to the stage of colon cancer, three primary treatment options such as surgery, chemotherapy, and radiation are performed.

In early-stage colon cancer:

Colonoscopy: Doctor may recommend this minimally invasive procedure for removing small polyps during colonoscopy.

Endoscopic Mucosal Resection: This procedure is used for removing larger polyps.

Laparoscopic Surgery: It used to remove those polyps that can’t be removed during colonoscopy.

When colon cancer has grown up and extended through the colon, the surgeon may recommend:

Partial Colectomy: In this procedure, a portion of the colon that contains cancer including a margin of normal tissue on either side of the cancer is removed.

A surgery is performed to create a way for waste to leave the patient’s body. A permanent or temporary colostomy is performed, when it’s not possible to reconnect the healthy portions of colon or rectum.

Lymph Node Removal: During colon cancer surgery nearby lymph nodes are also removed and tested for cancer.

Surgery for advanced cancer: In advanced stage cancer, when patient health is very poor, surgery can be performed to relieve a blockage of a scolon or other conditions to heal the symptoms of bleeding and pain.
In certain patients, when cancer has spread only to the liver and overall health of the patient is otherwise good, surgery can be performed to remove the cancer lesion from the liver. Also, Chemotherapy may be performed before or after this surgery.

Chemotherapy: It is usually performed after surgery, once cancer has spread to the lymph nodes. Various drugs are used to destroy cancer cells to minimise the risk of cancer recurrence. Sometimes, Chemotherapy may be performed before surgery to shrink the tumor before an operation.

Chemotherapy can also be performed to heal symptoms of colon cancer that has extended to other portions of the body.

In rectal cancer, chemotherapy is usually performed along with radiation therapy, before and after surgery.

Radiotherapy: This procedure is performed by using powerful energy sources, such as X-rays, to kill remaining cancer cells that might leave after surgery, and also shrinking large tumors before surgery for its easy removal to relieve symptoms.

Targeted drug therapy: In this procedure, drugs are used to target specific cancer cells during advanced colon cancer. Targeted drugs are generally given alone or in association with chemotherapy or alone. Researchers are still working to determine, who are most likely to benefit from the action of targeted drugs, side effects, and expensive cost.