Our body is full of wonders. It works all the time smoothly without you noticing anything.

I mean, let’s talk about the digestive tract. Do you feel your stomach digesting food? Do you feel the food you ate two hours ago making its way through your intestine? No, you don’t. Every part of the digestive system works normally and quietly in cooperation with other parts of the system.

What about the colon? We hear a lot of people complaining about colon problems.

The colon, or also known as the large intestine or the large bowel, is an organ and a part of the digestive system.

What does the Colon do?

The colon has a major role in how our bodies use the food we eat.

When you eat your food, the first station is the mouth where it gets chewed by the teeth into smaller pieces. Once the food is swallowed, it travels through the esophagus to the stomach. In the stomach, the food is further broken down into a liquid that is passed on to the small intestine.

In the small intestine, digestion of food continues with the help of the digestive juices of the pancreas and the gallbladder. The important vitamins and nutrients get absorbed from the small intestine. The leftover, which is usually liquids, moves to the colon. The water is absorbed from the colon.

In the colon, there is a type of bacteria that breaks down the remaining material, then the colon moves this material to the rectum.

So, as a quick recap:

The colon is considered the largest part of the large intestine.
The colon removes water and some nutrients and electrolytes from partially digested food.
The colon moves the remaining material, the stool, to the rectum where it is stored until it leaves the body.

So, this is how the colon normally works.

But what happens if there is an abnormality that interferes with this path?

What happens if there is Colon Cancer?

Have you heard about colon cancer before?

This is the main topic of our video today, so if you are interested, just keep on watching.

What is Colon cancer?

It is cancer that starts in the colon. Cancer that starts in the rectum is called rectal cancer.

It typically affects older adults; however, it can occur at any age.

So, how does colon cancer start?

All of the body’s cells normally grow, divide, and then die to keep the body healthy and normally functioning. But sometimes this process gets out of control. Cells start dividing without stopping. They also continue living beyond their lifespan even when they are supposed to die. When the cells of the colon start dividing and living uncontrollably, colon cancer will develop

In the case of the colon, it usually starts as small benign clumps of cells called “Polyps”. These polyps form on the inside of the colon and over time some of them become cancerous and turn into colon cancer. Colon polyps may be few and produce few or no symptoms at all. For this reason, it is very important to have regular colorectal screenings to detect any polyps of any abnormality early.

So, what are the possible symptoms that can indicate the presence of colon cancer?

Symptoms and signs of colon cancer include:

Persistent change in bowel habits including constipation or diarrhoea, or even changes in stool consistency.
Rectal bleeding or blood in the stool. However, it doesn’t necessarily indicate cancer, numerous other conditions can cause bleeding in the lower digestive tract such as hemorrhoids and anal tears.
Persistent abdominal discomfort such as pain, cramps, and gases.
Abdominal or pelvic bloating.
Incomplete evacuation of bowel or stool incontinence.
Weakness or fatigue.
Unexplained weight loss.
Unexplained anemia.
Vomiting.

But, again, in the early stages of colon cancer, patients may not experience any symptoms at all.

You must be curious now about the cause of colon cancer. I mean, what causes colon cancer to arise in the first place?

In fact, scientists are not sure yet what causes most colon cancers. However, in general, colon cancer begins when healthy cells of the colon develop DNA mutations. A cell’s DNA has all the instructions of the cell. It tells it when to divide, when to stop, and when to die.

But when a mutation happens, the cells will start dividing out of control. They will also start living beyond their lifespan as we mentioned before, which will lead to tumor formation eventually.

With time, the cancerous cells will grow and invade normal nearby tissue. The tumor may also spread elsewhere in the body to distant places.

Although scientists haven’t identified the exact causes of colon cancer, they have found some risk factors that increase the chances of developing it.

These risk factors include:

Old age. Colon cancer can be diagnosed at any age; however, the majority of colon cancer cases are above 50. Lately, the rates of colon cancer in people younger than 50 have been increasing, but doctors can’t identify the reasons.
Personal history of colorectal cancer or polyps. If a patient has already had colon cancer or noncancerous polyps, this patient is at a higher risk of developing colon cancer in the future.
Inflammatory intestinal conditions. Chronic inflammatory conditions of the colon such as Crohn’s disease and ulcerative colitis can increase the risk of colon cancer.
Inherited syndromes that increase colon cancer risk. Some genetic mutations can pass through generations and increase the risk of colon cancer. The most common inherited gene mutations that increase colon cancer risk are Familial Adenomatous Polyposis (FAP) and Lynch syndrome which is also known as hereditary nonpolyposis colorectal cancer (HNPCC).
Family history of colon cancer. Patients are more likely to develop colon cancer if they have a relative who had colon cancer before, especially first-degree relatives.
Low fiber, high-fat diet. A typical western diet may be associated with increasing cases of colon cancer.
Sedentary lifestyle. Inactive people are more likely to develop colon cancer.
Obesity. Overweight and obese people are more likely to develop colon cancer and die of colon cancer when compared to people with normal weight.
Diabetes. Diabetic people have a higher risk of developing colon cancer.
Alcohol. Heavy use of alcohol increases the risk of colon cancer.
Smoking. Smokers have a higher risk of developing colon cancer.
Radiation therapy. Radiations that are directed to the abdomen to treat previous cancers might increase the risk of colon cancer.

Knowing all these risk factors might make you stressed. I mean, you might have one or two of these risk factors.

So, how can you protect yourself? How can you prevent colon cancer?

Doctors always recommend that if you have an average risk of colon cancer, you should always consider screening around the age of 50.

Several screening options exist currently, each with its benefits and drawbacks. Although colonoscopy is the most recommended option, other methods are available.

Here are the most common screening tests:

Fecal immunochemical tests. In this test, doctors usually look for blood in the stool that is not easily seen by the naked eye.
Fecal DNA test. This test detects genetic mutations and blood products in the stool. Normal colon cells and their genetic material are passed with the stool normally every day. However, when polyps or tumors develop, the genetic material changes. These changes can be detected by laboratory analysis of the stool.
Flexible sigmoidoscopy. This method uses a flexible device called the sigmoidoscope to see inside the colon and the rectum as well. Unlike the device used in colonoscopy, this device is not as long, which limits how much of the colon can be seen. During a sigmoidoscopy, the device is inserted through the anus and up through the rectum and sigmoid colon. Gas is pumped during the procedure to allow the physician the best possible view of the inside of the colon.
Colonoscopy. It is the best method to check for colorectal polyps or cancer. In this method, the doctor uses a long scope called the colonoscope. It is usually an outpatient procedure to view the rectum and the entire colon. In this method, polyps can be removed to be tested in the laboratory for signs of cancer.
Double-contrast barium enema. This is an X-ray examination of the colon and rectum. In this test barium is given as an enema, through the rectum, the air is then blown to the rectum to expand the colon. It is not the most accurate method and shouldn’t be the method of choice when considering a screening method because it also requires bowel preparation.
CT colonography. In this procedure, a CT scan of the abdomen and pelvis is performed after making the patient drink a contrast dye and pumping air into the rectum.

These are all the screening methods used for the early detection of colon cancer.

Our role today is to answer most of your questions regarding colon cancer. Today we have Dr. Ahn, who is a leading doctor at Hanyang University Hospital in Seoul. He is going to discuss with us about colon cancer from an experienced medical point of view.

Interview

Dr. Byung Kyu Ahn Interview

Professor Ahn, what is exactly the large intestine and rectum, and where is it located in the gastrointestinal tract?

When we consume foods, food pass thru the duodenum from the stomach, then to the small intestines where the nutrients are absorbed, and once all the nutrients have been absorbed then moves onto the large intestines, which is divided into the colon and rectum. So, the rectum is the end part of the large intestines. This area collects defecation until it is ready to expel thru the anus.

Moving onto uh large intestinal cancer, what you call in Korean “dae jang ahm”. What is exactly “dae jang ahm” or colon cancer?

Colon cancer is cancer that starts in the colon. And rectal cancer is cancer that starts in the rectum. For men, the rectum covers about 15 cm from the anus and for women about 12 cm from the anus. So, rectal cancer affects this lower area and the cancer that affects the upper part is called colon cancer.

If somebody is diagnosed with colon cancer, are there any symptoms that shows?

Colon cancer symptoms are wide and vary, but colon cancer that emanates from the right side versus cancer that starts in the left side and rectal cancer all have slightly different symptoms. The cancer that starts in the right side, there are few symptoms initially, so as it develops and grows you can have constipation or lumps or black stools. The cancer that starts on the left side tends to have constipation due to the narrowing the colon or bloody stool. When the cancer is rectal, very frequent bowel movements, and the need to revisit the toilet after just going through a bowel movement, and bloody stool.

For example, if I have one of these symptoms, what kind of examinations I could take to confirm if it’s colon cancer or not?

The best way to confirm colon cancer is through endoscopy. Through endoscopy, the entire colon should be examined. If there are polyps or extraneous tissue discovered, it can be further ascertained if they are cancerous. Thus, the endoscopy is the best procedure to confirm presence of cancer.

I heard there are two kinds. There are colon polyps and colon cancer. What is the difference or what is the similarities?

Colon polyps can be considered the beginnings of colon cancer. So, if polyps are left alone untreated for a prolonged period, it has a high chance of turning into cancer. So, if polyps are present it is best if they are removed as it can prevent the development of colon cancer.

You said that colon polyps can develop into colon cancer. How about colon cancer, how many stages are there in colon cancer?

We can divide colon cancer into four stages, from first to fourth. In the first stage, with just surgery cancer can be cured. In the second stage, while the cancer has not spread to lymph nodes, it is more developed than the first stage and spread to the outer lining, the third stage is when the cancer has spread to the lymph nodes. The fourth stage, cancer has spread to the liver, lungs or lymph nodes.

In the case of colon cancer the most common treatment is surgery. But apart from surgery what other treatments there exists? For example, is it chemotherapy or radiation therapy, for example?

To complete get rid of colon cancer, the best treatment is surgery. Complete removal of cancer requires surgery. Chemotherapy and radiation therapy are supplementary treatments. Once again, to cure colon cancer, surgery is the best method. It is key to remove completely the cancer. Chemotherapy can be used in cases after surgery when it is likely recurrence will happen. For third stage and fourth stage, and even second stage cancers, chemotherapy can increase the chances of cure and lower the chance of recurrence after surgery. Also, radiation therapy can be used in rectal cancers in order to prevent spread to the pelvis.

In the case of other cancers, we hear they reappear after treatment. So, how about colon cancer, what is the probability of reoccurrence?

If we look at colon cancer overall, we see a 60% recurrence after treatment. However, it varies greatly between stages. For first stage cancer, there is a high cure rate of about 90%, for second stage when supplement with chemotherapy there is a 80% cure rate, for third stage cancer, the cure rate is about 60% to 70%, and in the fourth stage even with complete removal of the cancer, the likelihood of reoccurrence is about 50% to 60%, quite high. However, relative to other cancers, the reoccurrence is low and cure rate is high.

How about external stoma? In what cases is it performed?

External stomas are rarely performed. In right side colon cancers, it is rarely performed, but in left wing colon cancer or rectal cancer, it is performed due to the close proximity to the rectum or pelvis. And, in cases where there are colon obstructions that may take prolonged time to perform the surgery in one sitting, external stomas are performed and are returned to normal afterwards when the patient has recovered. However, in rectal cancers that are too close to the pelvis, the anus may need to be removed and a stoma created.

Colon cancer, if you have a history of colon cancer in your family, does it really impact the fact that you can get colon cancer?

Hereditary colon cancer is only about 10% of the occurrences. The remaining 90% start from polyps that grow into cancer. In reality, since only about 10% is hereditary, the rest are cancers that develop. For those with hereditary possibility when parents or siblings are prone to it, they need special care, and it may be best to get treatments and exams all together at a hospital that deals with colon cancer from the beginning.

We know that colon is directly related to food. So, after getting colon cancer surgery, for example, is there a diet you should follow, strict diet for example?

After colon cancer surgery, generally speaking, there is a consensus that colon cancer tends to occur more frequently with meat consumption. So, one should eat fruits and vegetables in ample quantities. Since, one cannot avoid proteins, chicken or fish should be consumed more than red meats. Instead of grilled, steamed is better for the prevention of colon cancer. The staple should be fruits and vegetables.

Talking about food. Is everyday diet, for example, if people drink alcohol or smoke, does it really impact the fact that you can get colon cancer?

Smoking or drinking can be seen as contributing factors to developing colon cancer. However, even after surgery, it can contribute negatively to recurrence of cancer. So, after getting surgery the patient must stop smoking and drinking. The most important is to get regular exercise. Exercise is the most important activity to prevent recurrence. Exercise at least 30 minutes a day and instead of red meats, fruits and vegetables are recommended.

Conclusion

Colon cancer is cancer that starts in the colon. And rectal cancer is cancer that starts in the rectum. For men, the rectum covers about 15 cm from the anus and for women about 12 cm from the anus. So, rectal cancer affects this lower portion and the cancer that affects the upper part is called colon cancer.

Colon cancer symptoms are wide and vary, but colon cancer that emanates from the right side versus cancer that starts in the left side and rectal cancer all have slightly different symptoms. The cancer that starts in the right side, there are few symptoms initially, so as it develops and grows you can have constipation or lumps or black stools. The cancer that starts on the left side tends to have constipation due to the narrowing the colon or bloody stool. When the cancer is rectal, very frequent bowel movements and bloody stools are common symptoms.

The best way to confirm colon cancer is through endoscopy. Through endoscopy, the entire colon should be examined. If there are polyps or extraneous tissue discovered, it can be further ascertained if they are cancerous.

Colon polyps can be considered the beginnings of colon cancer. So, if polyps are left alone untreated for a prolonged period, it has a high chance of turning into cancer. So, if polyps are present, it is best if they are removed as it can prevent the development of colon cancer.

We can divide colon cancer into four stages, from first to fourth. In the first stage, with just surgery cancer can be cured. In the second stage, while the cancer has not spread to lymph nodes, it is more developed than the first stage and spread to the outer lining, the third stage is when the cancer has spread to the lymph nodes. The fourth stage, cancer has spread to the liver, lungs or lymph nodes.

To completely get rid of colon cancer, the best treatment is surgery. Chemotherapy and radiation therapy are supplementary treatments.