Colon Cancer

Overview of Colon Cancer

Colorectal cancer (anat ka sartan/آنت کا سرطان) is a group of colon and rectum cancer. The tumor starts to grow in the lining of both the colon and rectum. These types of growth are known as polyps. If the polyps are in the colon or rectum area, they are referred to as polyps colon or rectum respectively. Polyps are characterized by a small non-cancerous lump of cells. As they grow, they can turn into cancer over time. 

Colorectal cancer has many stages of development, depending on the extent of cancer and the size of any tumor. The stages are as follows:

  • Stage 0:  Also known as carcinoma. It is a very early stage of cancer in which the growth of cells in the inner layer of the colon or rectum.
  • Stage 1: In this type, cancer spreads in the next tissue layer but does not reach the lymph nodes or any other cancer.
  • Stage 2: Cancer has expanded to the outer layers of the colon or rectum, but does not spread beyond them.
  • Stage 3: Cancer affects the outer layer of the colon or rectum to one of the three lymph nodes. But it does not spread to the other areas of the body.
  • Stage 4:  As stage 3 progresses, colon cancer starts to expand to other parts of the body such as the rectum. If the cancer cells accumulate to form a tumor in the rectum area as well then it is known as colorectal cancer. From there, cancer also extends to other parts of the body.

Prevalence of Colon Cancer (Colorectal Cancer)

As per the American cancer society (ACS) statistics, it accounts for 1 in 23 (4.4%) for men and 1 in 25 (4.1%) women cases of colorectal cancer were reported during their lifetime. 

In Pakistan, the overall cases of colorectal cancer are about 64% of the population till 2017. According to 2009-2015 data, the 5-year average survival rate for all stages of colon cancer is estimated to be 63 % and 67% for rectal cancer.



Signs and Symptoms of Colon Cancer

Common signs and symptoms of colon cancer (colorectal) do not appear in the early stages of cancer. As they appear, it depends on the size of the cancer and the location of the large intestine. Some of these are as follows:

  • Change in bowel movements, including diarrhea or constipation
  • Change in the consistency of your stool
  • Rectal bleeding or blood in the stool
  • Persistent abdominal discomforts, such as cramps, gas, or pain
  • A feeling that the bowel doesn't empty completely
  • Weakness or fatigue
  • Sudden weight loss

Types of Colon Cancer

There is more than one type of colon cancer according to the type of polyps. Because these types of polyps transform into cancer in specific areas of the colon or rectum. On the basis of them, it is further sub-categorized into the following forms:

  • Adenocarcinomas- It is the most common type of all. Typically, adenocarcinoma forms within the cells that make the mucus in either the colon or rectum.
  • Lymphomas-This is defined as cancer of immune system cells. Generally, lymphomas start in the lymph nodes but can also affect the colon, rectum, or other organs first.
  • Carcinoids- It starts to form hormone-making cells within the large intestine.
  • Sarcomas- It is a cancer of soft tissues of a specific region such as connective tissues of the colon or rectum.
  • Gastrointestinal Stromal Tumours- The GIST or gastrointestinal stromal tumors of cancer form the non-cancerous cells (benign) in the colon area. As they grow, benign cancer changes into malignant cancer. (tumors mostly develop in the digestive tract but can rarely exist in the colon area). 

Causes of Colon Cancer

Almost all colon and rectal cancers start in the form of polyps. Polyps are not cancer, but the growth of cells in the inner wall of the colon.

Following are the most common types of polyps in the colon and rectum that cause cancer, if it is left untreated:

  • Hyperplastic and Inflammatory Polyps - These are a non-cancerous type of large-sized polyps formed on the right side of the colon. If it is not removed on time that may result in cancer.  
  • Adenomas or Adenomatous Polyps - These are precancerous polyps, which can change into colon or rectal cancer.  
  • Genetic Mutations -Due to mutations in the DNA or genetic damage, uncontrolled cell growth has been observed in colorectal cancer.


Colorectal cancer may also form due to the replication of abnormal cells, called dysplasia, in the lining of the colon or rectum.



Risk Factors of Colon Cancer

Factors that may increase the following risk of colon cancer:

  • People older than 50yrs
  • African-American people are more likely to develop colon cancer.
  • Personal history of colorectal cancer or polyps
  • Inflammatory intestinal conditions such as  ulcerative colitis and Crohn's disease 
  • Inherited syndromes that trigger colon cancer due to gene mutations that pass through generations of the family such as
  • Familial adenomatous polyposis (FAP) 
  • Lynch syndrome (also known as hereditary nonpolyposis colorectal cancer HNPCC)
  • Juvenile polyposis syndrome
  • Muir–Torre syndrome, which is a variant of Lynch syndrome
  • MYH associated polyposis
  • Peutz–Jeghers syndrome
  • Turcot syndrome, which is another variant of FAP
  • People who had a family history of colon cancer
  • Eating Low-fiber and high-fat diets such as red meat and processed meat.
  • Less physical activity in lifestyle
  • Diabetic or insulin resistance people 
  • Obesity
  • Smoking
  • Alcohol
  • Radiation therapy for cancer

Complications of Colon Cancer 


  • Problems in the bowel movement 
  • Cancer returning in the colon 
  • Development of secondary cancer 
  • The cancer spread to other organs and tissues



In order to minimize the symptoms of colorectal cancer, the following measures should take:

  • Decreasing the amount of red meat you eat
  • Avoid processed meats, such as hot dogs and deli meats
  • Eat more plant-based foods
  • Decrease dietary fat
  • Physical activities on a daily basis
  • Lose weight
  • Quit smoking
  • Reduce alcohol consumption
  • Decrease stress
  • Manage preexisting diabetes


Doctors will do a physical examination to check the swollen mass in the organs. After that, they recommend any one of the following tests for polyps or colorectal cancer:

  • Rectal Examination- To check the rectum for growth of the tumor with the help of fingers. 
  • Colonoscopy- The colonoscopy is a standard screening test to check the entire colon or rectum whether there are any abnormalities in them. A doctor placed a thin, flexible tube called a colonoscope for examination.
  • Sigmoidoscopy- Another test to check the rectum and the last part of your colon.
  • Biopsy- In a biopsy procedure, a doctor extracts out the affected tissues during a colonoscopy or sigmoidoscopy for testing. This is done with the help of a fine needle. A CT scan or ultrasound locates the area of tissues. Although complications are rare, this test may cause bleeding or discomfort.
  • Stool DNA- This test reveals the specific genes that may cause colon cancer.
  • CT Colonography- This is a special X-ray (also called a virtual colonoscopy) of the entire colon which takes less time and is less invasive than other tests. But if it shows a polyp, then a colonoscopy is required.
  • Barium Enema X-ray- This is a type of X-ray that involves putting dye in the colon. It can find trouble spots that might mean it needs a colonoscopy.
  • Other imaging tests- MRI or ultrasound can give the doctor detailed scans of organs.

Treatment of Colon Cancer | When to Consult a Doctor

The treatment of colorectal cancer depends on a variety of factors. The state of overall health and the stage of colorectal cancer will help the doctor for a treatment plan. Apart from it, people also use natural remedies for the rapid increase in treatment. 

1. Natural Remedies

Several natural herbs are used to treat colorectal cancer that is as follows:

  • Garlic
  • Plant antioxidants such as Blueberries, cranberries, pomegranates, carrots, apricots, avocado, tomato and apple
  • Olive oil 
  • Selenium rich foods
  • Spices
  • Omega-3- oils
  • Ginseng tea
  • Ashwagandha
  • Green tea
  • Aloe vera and apple cider mixture
  • Turmeric

2. Surgery

In this procedure, the removal of cancerous polyps from the colon. If the cancer polyps are not attached to the walls of the bowels, then surgery is quite easy. 

As the cancer metastases into the bowel walls, then an expert surgeon removes a portion of the colon or rectum with lymph nodes. It all depends on the surgeon to reattach the remaining healthy area of the colon to the rectum.

In some cases, it is difficult to perform a colostomy because of the opening of the abdominal wall for waste removal.  

3. Chemotherapy

In some cases, it is conducted along with other treatments. It involves cancer-killing drugs that help to control the growth of cells. This is helpful to prevent the growth tumour at colorectal cancer metastasis sites

Several chemotherapy drugs used to treat colorectal cancer such as

  • Capecitabine (Xeloda)
  • Fluorouracil
  • Oxaliplatin (Eloxatin)
  • Irinotecan (Camptosar)

Chemotherapy often causes side effects that are controlled with additional medications.

4. Radiation Therapy

Colorectal cancer radiotherapy uses high-powered beams of energy, such as X-rays and protons, to kill cancer cells. It can be used before the surgery to shrink or remove the tumour from the colon. Also, be used after surgery to kill remaining cancer. 

5. Targeted Drug Therapy

In this therapy, cancer drugs or other measures are used to target the specific site of cancer cells and destroy them. For colorectal cancer, targeted drug therapy is given with chemotherapy for advanced treatment of cancer.

Targeted therapies and immunotherapies may also be recommended following the Food and Drug Administration (FDA) to treat colorectal cancer.

  • Bevacizumab (Avastin)
  • Ramucirumab (Cyramza)
  • Ziv-aflibercept (Zaltrap)
  • Cetuximab (Erbitux)
  • Panitumumab (Vectibix)
  • Regorafenib (Stivarga)
  • Pembrolizumab (Keytruda)
  • Nivolumab (Opdivo)
  • Ipilimumab (Yervoy)

They are used to treat metastatic, or late-stage, colorectal cancer that doesn’t respond to other treatment procedures.

6. Immunotherapy

Immunotherapy is a drug treatment that stimulates the immune system to kill cancer efficiently. This is done by interfering with the cancer cells producing proteins due to colorectal cancer. 

For colorectal cancer, immunotherapy might be used for advanced cancer but stop the relapse of it.

7. Supportive (Palliative) Care

After the treatment, palliative care is provided to the patients to reduce the after-effects of it. This helps to improve the quality of life of patients. 

For people who have a polyps history in the colon and rectum area or if the symptoms get worse, consult oncologists and gastroenterologists.


During or after treatment, the patients should attend follow-up sessions for careful monitoring of them. Otherwise, the chance of relapse may occur.