Colon cancer

Last updated date: 12-Oct-2022

Originally Written in English

Colon cancer

Colon cancer is a form of cancer that usually starts within the large intestine (colon) and can spread throughout the body. The colon is the last section of the digestive system. This cancer is more common in older people, although it can strike anyone at any age. 

Colon cancer normally starts as polyps, which are tiny, noncancerous, or benign clusters of cells that develop on the inside part of the colon. Some of these polyps can turn into colon cancer with time. They are small and can cause few symptoms, if any. As a result, medical providers advise routine screening to prevent colon cancer by detecting and eliminating polyps before becoming cancerous. 


Signs and Symptoms of Colon Cancer 

Signs and Symptoms of Colon Cancer 

During the early stages of colon cancer, there are generally no symptoms. But with time, as the condition advances, the symptoms become more evident. The following are some of the common signs and symptoms of colon cancer

  • Constipation or diarrhea
  • Stool consistency changes
  • Stools that are slack and narrow
  • Presence of blood in the feces which might or might not be noticeable 
  • Stomach aches, bloating, cramps, or gas
  • Constant impulses to defecate in spite of passing stools
  • Weariness and weakness
  • Unexpected weight loss
  • Irritable bowel syndrome (IBS) 
  • Iron deficiency anemia

When colon cancer metastasizes to another part of the body, including the liver, it might lead to new symptoms in that area.


Causes of Colon Cancer 

The underlying causes of colon cancer are unknown. But generally, colon cancer develops when the DNA of healthy colon cells undergoes mutations. The DNA of a cell carries instructions that tell it what to do. 

The healthy cells develop and multiply in a regular pattern to keep the body's functions smooth. However, if the DNA of a cell gets damaged and it becomes malignant, the cell keeps on dividing even as the new cells are not required. A tumor develops as the cells build up. 

The cancerous cells can grow large enough to enter the normal surrounding tissue and destroy it over time. Furthermore, malignant cells have the ability to spread or metastasize to other locations of the body, creating deposits there. 


Risk Factors of Colon Cancer 

The following factors can raise your risk of developing colon cancer;

  • Age: Although colon cancer can strike anyone at any age, most people diagnosed with the condition are over 50. 
  • Inflammatory intestinal disorders: Colon inflammatory illnesses including ulcerative colitis and Crohn's disease can raise your chances of getting colon cancer. 
  • Having had colorectal cancer or polyps in the past: You are at a high risk of getting colon cancer later in life if you have previously had colon cancer or benign colon polyps.
  • Hereditary disorders that raise the risk of colon cancer: Certain genetic changes passed down through generations can dramatically increase colon cancer risk. Inheritable genes are associated with just a small fraction of colon cancers. Familial adenomatous polyposis (FAP) and Lynch syndrome are the two most frequent genetic disorders linked to an increased risk of colon cancer.
  • A high-fat and low-fiber diet: A normal Western diet, rich in fat and calories and low in fiber, may be linked to colon cancer. According to some research, individuals who consume a diet rich in red meat or processed meat have a higher risk of developing colon cancer. 
  • Family background of colon cancer: Having a close family member who has had colon cancer increases your chances of developing it. Also, your chances are even higher if you have more than one blood relative with colon or rectal cancer. 
  • A sedentary way of life: Inactive people are more likely to get colon cancer. Nonetheless, colon cancer risk may reduce if you engage in regular physical exercise and other activities.
  • Obesity: Unlike individuals with average weight, those who are obese have a higher risk of colon cancer. This also includes an increased possibility of dying from colon cancer. 
  • Diabetes: Colon cancer is more likely in people who have diabetes or insulin resistance.
  • Smoking: Smokers may be at a higher risk of developing colon cancer.
  • Radiation therapy (cancer treatment): Radiation therapy used to treat prior tumors in the abdomen raises the risk of getting colon cancer.  
  • Alcohol use: Colon cancer is more likely if you consume too much alcohol.


Colon Cancer Diagnosis 

The signs and symptoms you experience may indicate that you have colon cancer. In such cases, the doctor or oncologist may suggest one or more diagnostic tests and procedures, such as; 

  • Colonoscopy (examining the inside of the colon using a scope)

Colonoscopy is a procedure that involves viewing the whole colon and rectum. This is done through a long, flexible, and narrow tube connected to a video camera and computer. If the doctor discovers a suspicious spot, he or she can use surgical equipment to remove polyps and obtain tissue samples (biopsies) for evaluation. 

  • Blood tests

There is no way to detect if you have colon cancer using a blood test. On the other hand, the doctor may perform blood tests to determine your overall health, including the functional tests of the kidney and liver. 


Colon Cancer Screening:

To check the indicators of colon cancer or other benign colon polyps, the oncologist can suggest screening tests for healthy individuals without any symptoms or signs. The best chance for a cure and successful recovery is to diagnose colon cancer while at the early stage. Generally, colon cancer screening helps minimize the chance of death from the disease. 

According to the physicians, individuals who have an average risk of developing colon cancer should start screening at the age of 50. People at a higher risk of colon cancer, including those who have a family history of the disease, can consider immediate screening. 

There are various screening choices available, each with a set of advantages and disadvantages. It’s thus essential to talk to the doctor concerning your options to determine the right test. If the doctor performs a colonoscopy for screening, he or she can eliminate the polyps during the operation before they become cancerous. 


Colon Cancer Treatment 

The best colon cancer treatment usually depends on the location of cancer, stage, and any other health concerns you may have. The following are common treatments options for colon cancer; 

Colon cancer surgery in the early stages:

For the relatively small colon cancer, the doctor may suggest a less invasive surgical procedure. Depending on your condition, you may undergo one of the following surgeries; 

  • Polypectomy (polyps removal during a colonoscopy: The doctor can totally remove the tumor during a colonoscopy if it is small, localized, entirely contained in a polyp, and still in its early stage.  


  • Endoscopic mucosal resection: During a colonoscopy, the practitioner can remove the large polyps with specialized equipment and extract the polyp as well as a small portion of the colon's inner lining in the endoscopic mucosal resection approach. 
  • Laparoscopic surgery (minimally invasive surgery): Laparoscopic surgery can be used to remove polyps that can't be eliminated during a colonoscopy. The procedure involves putting devices attached to cameras through multiple small incisions made in the abdominal wall. The camera will then portray the colon on the monitor. Your surgeon can as well obtain small samples from lymph nodes in the cancerous site. 

On the other hand, if the colon cancer has advanced, the surgeon can suggest the following surgical procedures; 

  • Partial colectomy 
  • Procedure to create a passage for the waste products to exit the body 
  • Removal of the lymph node



Chemotherapy uses medications to destroy cancerous cells. Chemotherapy is usually administered after surgery in colon cancer patients to kill any remaining malignant cells. Also, chemotherapy can help slow the progression of cancer. 

Colon cancer is usually treated with chemotherapy medicines such as capecitabine (Xeloda), oxaliplatin (Eloxatin), Fluorouracil, and irinotecan (Camptosar). 


Radiation therapy:

Radiation therapy destroys the cancerous cells using high-energy sources like x-rays and protons. It could also be used to reduce a larger cancer before a procedure, making it easier to remove. In addition, radiation therapy can help ease symptoms like colon cancer back pain when surgery is not an alternative. Chemotherapy and radiation are sometimes used together. 


Targeted drug therapy:

This therapy is designed to target certain abnormalities found in cancer cells. Targeted drugs treatments can kill cancer cells by inhibiting these anomalies. Chemotherapy is frequently used in conjunction with targeted drugs. Targeted drugs therapy is normally reserved for patients with advanced colon cancer. 



Immunotherapy is a cancer-fighting medicine that activates the body's immune system. Since the cancerous cells generate proteins that prevent immune system cells from identifying malignant cells, the disease-fighting defense system may fail to fight cancer. Immunotherapy thus works by altering the immune system's natural processes. This treatment is often used only in the case of advanced colon cancer. 



Colon cancer develops if the cells lining the colon become abnormal and grow uncontrollably. Since the symptoms don’t always show during the earlier stages, routine colon cancer screening is essential. Early diagnosis and treatment increase the chances of successful recovery. 

Most patients with colon cancer can continue to live their normal lives. Today's treatments have good results. However, you may need numerous treatments and even a combination of various treatments to have a good opportunity of avoiding cancer recurrence. The most common combination includes surgery, chemotherapy, and radiation therapy.