Colon Polyps

1 What Are Colon Polyps?

At the end of the digestive tract is the large intestine, also called the colon. It is a long, hollow tube. Colon polyps are small growths on the lining of the large intestine (colon). Usually harmless, some colon polyps can develop into colon cancer, a cancer that can be fatal if detected at an advanced stage. It can affect anyone, but your risk is higher if you are aged fifty or older, are overweight or a smoker, or have a personal or family history of colon polyps or colon cancer.

Colon polyps start off as a small bump in the lining. Later, it grows to look like a mushroom. They occur on the inner lining of the large intestine and protrude into the colon. The polyps are not necessarily dangerous; most are benign. Over a period of time, some can become cancerous. Usually, polyps smaller than the size of a pea are harmless. The larger ones, however, can develop into cancer. To be safe, gastroenterologists prefer to remove all polyps and have them tested.

Generally, the immature cells at the lining of the colon divide, mature, and then die. This happens in a very consistent and timely manner. But genetic changes may prevent the cells from maturing; hence, the cells do not die, leading to the accumulation of immature, abnormal cells. This leads to the formation of polyps. This event can occur after or before the birth of an individual.

Appearance of Polyps

  • Polypoid polyps: These look like a mushroom and, since they are attached to the colon lining with the help of a thin stalk, they flop around the intestine.
  • Sessile polyps: These are without a stalk and are attached to the colon lining by a broad base.
  • Flat polyps: These are flat or slightly depressed, so they are not as pronounced as the polypoid or sessile polyps. These are the least common colon polyps.

Most often, colon polyps do not produce any concerning symptoms. Regular screening tests, such as a colonoscopy, are recommended, as early detection can prompt early treatment and thus better outcomes.

Colon cancer can be prevented if colon polyps are detected early, through regular screening.

The common types of colon polyps are: 

  • Adenomatous: This type accounts for approximately 60% of all polyps. Only a small number of people with this type may develop cancer. They are the most common type of polyp as well as a common cause of colon cancer. The chances of them developing into a cancer partially depend on the size; the larger the size, the greater the chances of them becoming malignant. The number of polyps also matters. People with multiple polyps are usually not malignant and have chances of developing additional polyps, which may become malignant. The malignant potential depends on the organization of the polyps’ cells. If they are arranged in tubular structures, they are less likely to become malignant than the cells arranged into finger-like structures.
  • Serrated: Serrated polyps may become cancerous. Hyperplastic polyps are the second most common type of polyp. They have little or no potential to become cancerous unless they are proximally located or show a particular histologic pattern under the microscope. If the large, serrated polyps are located in the ascending colon and the patient has a family history of colon cancer, they may be at risk for developing colon cancer. Sometimes, hyperplastic polyps coexist with the adenomatous type.
  • Larger, serrated polyps: These precancerous polyps are not easily detected.
  • Inflammatory: These polyps occur after episodes of ulcerative colitis or Crohn's disease of the colon and are not cancerous. However, ulcerative colitis or Crohn's disease naturally puts you at an increased risk of colon cancer.

Polyp size can vary from a few millimeters to several centimeters. The larger the size of the polyp, the more likely it will later become cancerous, or it might already be cancerous.

2 Symptoms

Colon polyps are generally asymptomatic and can be accidentally detected during a routine examination of the bowels. However, the following signs may be present in some people:

  • Rectal bleeding: This could signal colon polyps, cancer, or other conditions, such as hemorrhoids or minor injuries in the anus.
  • Change in stool color: Black-colored stool is an indication of bleeding in the upper gastrointestinal tract. Certain foods, medications, and supplements can also alter stool color. 
  • Constipation or diarrhea: Bowel habit changes, such a constipation or diarrhea, could signal a large polyp, but these signs can also be caused by a number of other conditions.
  • Pain, nausea, or vomiting: When blocked by a large colon polyp, the bowels may cause abdominal cramps, nausea, and vomiting. 
  • Iron deficiency anemia: Loss of blood over time can deplete iron from the body, which can cause signs like tiredness and shortness of breath
  • Weakness, light-headedness, rapid heart rate, and pale skin due to an iron deficiency
  • Intussusceptions: This is a condition in which the polyp attached to the colon drags that portion of the colon into the more distal colon. This leads to obstruction of the colon. Its signs and symptoms include abdominal pain, nausea, vomiting, and distention.  

Visit your doctor if you have: 

  • Abdominal pain 
  • Blood in the stool 
  • Constipation, diarrhea, or other changes in bowel habits that last for more than a week 

Screen regularly for polyps if you are: 

  • Aged fifty or older 
  • At high risk (due to a family history of colon cancer

If you have other risks for polyps, you need to start screening much earlier than fifty.

They are very common and more prevalent in people above age sixty. One third of people in this age bracket will have at least one polyp. A person with colon polyps is likely to have additional ones elsewhere in the colon, and new polyps may form at a later date. Colon polyps may give rise to colon cancer. Due to further mutations and changes in the genes of cells, benign polyps may become malignant. The cells give rise to larger polyps by dividing uncontrollably. Initially, these cells are limited to the lining of the colon, but they later invade deeper into the wall of the colon. Somecells might break off from the polyp through the wall of the colon, spreading to the lymph channels, then the local lymph nodes, and then slowly throughout the body. This is referred to as metastasis. The earlier phase of the transition from benign to malignant polyp is called low-grade dysplasia. In this phase, the cells and their relationship to one another is abnormal; when the relationships become even more abnormal, it is referred to as high-grade dysplasia. This is of greater concern, since the cells are already cancerous. They need to be removed or else invasion and metastasis may occur.

3 Causes

Colon polyps are caused by changes in the DNA of the cells that line the colon. These changes (DNA mutations) cause out-of-control growth and multiplication of cells. The cells can form a mass, called polyps, in the intestine. A larger polyp carries a greater risk of developing into cancer.

4 Making a Diagnosis

Your doctor may refer you to a gastroenterologist (a specialist in digestive disorders) in order to make a diagnosis of colon polyps.

How to Prepare for the Visit

Preparing for the visit can optimize the therapy and make the visit more fruitful.

List out all symptoms; write down your key medical information as well as the names of all your medications, vitamins, or supplements; ask a friend or family member to accompany you during the visit.

Make a list of questions to ask your doctor. Some typical questions include: 

  • What could be the possible causes of my symptoms? 
  • What are the tests that I need? 
  • What are my treatment options? 
  • Can these polyps turn into cancer
  • Is my condition related to heredity? 
  • Do I need follow-up testing? 
  • Are there any food restrictions? 

A clear talk with your doctor can optimize the therapy and improve the outcome. Prepare yourself to answer some essential questions from your doctor. The doctor may ask you typical questions like: 

  • When did you start noticing your symptoms and how severe are they? 
  • Do your symptoms appear continuously or occasionally? 
  • Do you have a personal or family history of colon cancer or colon polyps? 
  • Does anyone in your family have other cancers of the digestive tract, uterus, ovaries, or bladder? 
  • Do you smoke and/or drink? If yes, how often? 

Screening tests are carried out to determine if the colon polyps are cancerous. These tests can also detect early colorectal cancer, thus ensuring a better recovery. Screening methods include: 

  • Colonoscopy: This provides the most accurate results when it comes to colorectal polyps and cancer. If a colonoscopy shows polyps, they may be removed during the procedure or a sample may be sent to the lab for analysis (biopsies). A flexible tube five feet in length is used. The tube has a light and a camera at the end and a hollow channel through which the instrument is passed. A colonoscope is passed into the colon via the anus and from there to the proximal end of the colon (the caecum). The lining is examined for polyps or any other abnormalities. Almost 95% of polyps, small or large, are identified by colonoscopy. However, if the polyps are small, hidden by the fold in the colon’s lining, or are flat, or if diagnosis is hurried, the polyps may be missed.
  • Virtual colonoscopy (CT colonography): A CT scan is used to view the colon. Preparatory requirements of both a virtual and regular colonoscopy are the same. If a polyp is found, the colonoscopy can remove it. The colon is filled with a liquid contrast agent or air. Then, a CT or MRI can be performed to provide a virtual image. It mimics the view obtained by the colonoscope. It is not as good as a colonoscopy, and if the polyps are smaller than one centimeter, they can be missed by this method. An MRI does not expose the patient to radiation and thus has an advantage over the CT, but it is far more expensive and there is less experience with MRIs than with CTs. If a polyp is found via CT and MRI virtual colonoscopy, a further colonoscopy needs to be done for its removal.
  • Flexible sigmoidoscopy: This uses an elongated, lit tube, which is inserted through the rectum to the sigmoid. If a polyp is found, a colonoscopy can remove it. The tube is three feet in length and can be used to identify, perform a biopsy, and remove polyps. Since the entire colon cannot be examined by it, this diagnosing method has to be combined with a tool occult blood test or colonoscopy. This is done to identify polyps that are beyond its reach. 

5 Treatment

Early detection of colon polyps can prompt early treatment and thus better outcomes.

Surgery for polyps include: 

  • Removal during screening: The doctor can remove the polyps while screening by using biopsy forceps or a wire loop. A liquid can be injected under a polyp (larger than 0.75 inches) to lift it off the wall to facilitate removal (endoscopic mucosal resection).
  • Minimally invasive surgery: This technique is used to remove large polyps or those that are inaccessible during screening. 
  • Colon and rectum removal: Surgery to remove the colon and rectum (total proctocolectomy) is employed in cases of a rare inherited syndrome, such as familial adenomatous polyposis (FAP). 

You are more likely to develop colon cancer if you have a history of an adenomatous polyp or a serrated polyp. The number, size, and type of polyps present before surgery determine one’s risk and future need of colonoscopy. You may need a colonoscopy:

  • In five years if only one or two small adenomas were present
  • In three years if more than two adenomas measuring 0.4 inches (about 1 centimeter) or larger, or adenomas with a broad base (villous) were present 
  • Within three years if more than ten adenomas were present
  • Within six months if a very large adenoma or an adenoma that had to be removed in pieces was present

Preparing yourself for a colonoscopy is very important. Remember, you need an empty colon for the colonoscopy, as it provides the doctor a clearer view of your colon. 

6 Prevention

Apart from regular screenings, lifestyle modifications can also prevent colon polyps and colorectal cancer. Here are some suggestions: 

  • Follow a diet rich in fruits, vegetables, and whole grains. 
  • Limit your fat intake. 
  • Drink in moderation. 
  • Say “No” to tobacco. 
  • Maintain a healthy weight through a combination of physical exercise and healthy weight management. 
  • Calcium supplement: Studies suggest calcium may help prevent recurrence of colon adenomas, but its role in colon cancer is still unclear. The benefit of supplementing 1200mg of calcium per day has been seen, however, higher dietary and supplemental levels of calcium are associated with an increase in vascular disease. Hence, the study performed recommended 800 mg calcium per day.
  • Aspirin: Regular aspirin is shown to reduce one’s risk of polyps. However, consult a doctor before taking aspirin, as it may cause gastrointestinal bleeding. Non-steroidal and anti-inflammatory drugs have received the best support in treating polyps. Aspirin has been shown to reduce its formation by 30%–50%. Effect is likely to occur with higher doses, but aspirin’s side effects are also a concern. 
  • Celecoxib (celebrex): A “COX-2 selective NSAID,” or Cox-2 inhibitor, this has also shown to reduce polyps. However, its side effects are of concern. It can be used in patients with genetic polyposis. Sulindac (Clinoril) is a “non-selective NSAID” and has also shown to prevent polyps in genetic syndromes as well as sporadic adenomas. However, there is concern regarding its side effects, too.
  • A patient with an average risk of forming additional polyps is generally not recommended to be treated for its prevention, since the risks of the treatment might outweigh the benefits. Patients at a higher risk, however, may be treated.

You may want to have genetic counseling if colon polyps are prevalent in your family. Regular colonoscopies should begin in young adulthood if you are known to have a hereditary disorder that causes colon polyps. 

7 Risks and Complications

There are several risk factors that increase your risk of having colon polyps, including:

  • Age: Being fifty or older
  • Inflammatory bowel diseases, such as ulcerative colitis and Crohn's disease 
  • Family history: You're at a higher risk of colon polyps or cancer if your parent, sibling, or child has the condition. 
  • Tobacco and alcohol use 
  • Obesity
  • Lack of exercise.
  • Race: African-Americans are more likely to develop colon cancer
  • Type II diabetes with uncontrolled blood sugar 
  • Hereditary polyp disorders: There are many genetic disorders that cause polyps and raise your risk of colorectal cancer. Screening and early detection are recommended to prevent the polyps from becoming cancerous.

Hereditary polyp disorders include: 

  • Lynch syndrome (hereditary nonpolyposis colorectal cancer): Lynch syndrome causes a few, but malignancy-prone polyps. There are some links between this syndrome and tumors in the breast, stomach, small intestine, urinary tract, and ovaries. 
  • Familial adenomatous polyposis (FAP): This is a rare genetic disorder that leads to the formation of numerous polyps in the lining of the colon. Symptoms may start early, during one’s teen years. If left untreated, the polyps develop into colon cancer in almost all cases, usually before age forty. Genetic testing may be recommended to determine your risk of FAP. 
  • Gardner's syndrome: In this variant of FAP, polyps are present all over the colon and small intestine. Noncancerous tumors may also be present in other parts of the body like the skin, bones, and abdomen. 
  • MYH-associated polyposis (MAP): This is associated with MYH gene abnormalities and is similar to FAP. MAP causes multiple adenomatous polyps and colon cancer at a young age. Genetic testing may be recommended to determine your risk of MAP.  
  • Peutz-Jeghers syndrome: This leads to the formation of noncancerous polyps throughout the intestines. 
  • Serrated polyposis syndrome: This condition affects the upper part of the colon and causes multiple serrated adenomatous polyps to form. These polyps may become cancerous.

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