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Colon polyps Cancer

Overview of Colon polyps cancer

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Colon polyps are fleshy mucosal protrusions, which arise from the inner epithelial lining of the colon, which vary in size, shape and histopathology. They usually do not cause any symptoms until their size increases sufficient enough to cause obstruction resulting in rectal bleeding. Colon polyps are of much concern, as they are capable of becoming malignant. Studies have shown that early detection and removal of colon polyp decreases the occurrence of invasive cancer.1 Colon polyps are classified as non-neoplastic and neoplastic polyps.1

Non-neoplastic polyps are further classified as:

  • Mucosal polyps—These are normal mucosal protrutions and resemble a polyp which is found in the colon.
  • Hyperplastic polyps—They develop from a focal abnormality in cellular replication and are commomly found in the rectum.
  • Juvenile polyps—These are epithelial retention polyps composed of cystically dialated glands filled with mucus and thickened with inflammatory material.
  • Peutz-Jeghers polyps—These lesions range from 1–3 cm are multiple and composed of mature intestinal epithelial cells.

Neoplastic polyps are also termed as adenomas. They are tumors which are made up of benign neoplastic epithelium.

They include:

  • Tubular adenomas—They are composed of a mass of tubular glands, producing a polyp with a rounded surface.
  • Villous adenomas—These are composed of finger-like epithelial projections extending outward from the surface.
  • Mixed tubular and villous adenomas - These are composed of both types of tissues.

Occurrences of colon polyps cancer in different groups:: Occurrences of polyp are common and the incidence increases with age. It is estimated that about 50% of people above 60 years of age are affected with one kind of polyp. Men and women are equally affected. Epidemiologic studies have shown that environmental causes also add to the colon polyp incidence in geographically distinct populations. The risk of isolated polyps (about 1 cm) developing into cancer is 8% at 10 years and 24% at 20 years. Recent studies have shown that aspirin, folic acid and calcium intake reduces the polyp formation and guard against development of colorectal carcinoma.3


Signs and Symptoms of Colon polyps cancer

The person does not experience any symptoms initially, as the polyps are small.

Later on as the disease advances, the following symptoms can be observed.

  • Anemia due to bleeding from polyps.

Causes and Risk Factors of Colon polyps cancer

The following are some of causes and risk factors for colon polyps cancer:

environmental causes, family history. consumption of alcohol.

  • Environmental causes
  • Differences in consumption of dietary fiber and antioxidants
  • Consumption of meat, fat and alcohol
  • Family history
  • Risk increases with age
  • Men are at more risk when compared to women
  • Low fiber diet
  • Sedentary lifestyle
  • Being overweight
  • Inherited gene mutations like Familial adenomatous polyposis (FAP), Gardner's syndrome, hereditary nonpolyposis colorectal cancer (HNPCC).



Diagnosis of Colon polyps cancer

Colon polyps can enlarge in size and cause bleeding or pain, hence it cannot be diagnosed with blood tests.

The diagnotic tests used in screening colon polyps and as follow-up tests include:

Fecal Occult Blood Test
To detect the presence blood in the stool. Studies have shown that this test has reduced the deaths caused due to colon cancer.1

Digital Rectal Exam
Digital rectal exam is used to identfy the presence polyps in the lower areas of the rectum.

Double-Contrast Barium Enema
For the detection of large polyps more than 7 mm. This is an X-ray of large intestine.
Flexible Sigmoidoscopy
The lower third of the colon is visualized to check for the presence of polyps. Samples are collected for biopsy. Precancerous and cancerous polyps are removed. Studies have shown that flexible sigmoidoscopy combined with fecal occult blood test can detect 76% of advanced cases of colon polyps and cancers.2
The whole colon can be visualized. Samples can be removed for biopsy. Precancerous and cancerous growth can be removed. Screening, if done in the earlier stages will be helpful for those who are at very high-risk for colon polyps and colon cancer.3 During colonoscopy tissue samples from the lesions are taken for microbiological examination to identify the polyp.


Optical Colonoscopy
This is a very sensitive method where a fiber optic colonoscope is inserted from the anus to the ileocecal valve to get the images of the colonic lining. Air and saline are injected and the scope is rotated. The patient is sedated and is also rotated into different positions and the polyps are removed.

Other tests include CT scan to view the colon and genetic testing of stool samples.



Treatment of Colon polyps cancer

Usually, colon polyps do not cause harm if they are benign but if malignant, the following treatment is involved. 

  • Removal of adenomatous polyps detected during sigmoidoscopy and colonoscopy.
  • Colon polyps bigger than 1 cm, containing cancer cells have to be removed.1
  • Colon polyps smaller than 5 mm need not be removed until and unless they contain cancer cells, which take many years to pose risk. It is removed in people who have a family history of polyp syndrome.2
  • Exisulind is another drug, which induces apoptosis (programmed cell death) in precancerous and cancerous cells.
  • If colon polyps have broad area of attachment to the colon wall and have chances to develop into cancer, surgery may be preferred if colonoscopy does not work.
  • If cancer is found in the colon polyp, treatment for colorectal cancer can be started.


Prevention and Early Management

Colon polyps can be managed early by regular screening which is usually done above the age of 50 years. Some of the screening tests are:

  • Fecal occult blood test every year
  • Flexible sigmoidoscopy every 5 years
  • Colonoscopy every 10 years
Apart from the above points, the following points can also be considered.9
  • Consuming low-fat, high-fiber diet.
  • Maintaining healthy body weight and being physically active.
  • Reduce alcohol consumption.
  • Taking calcium supplements.
  • Using turmeric protects against colon polyp.
  • Including fresh fruits, vegetables and cereals in diet.

Written by: Healthplus24 team
Date last updated: March 16, 2014