Colon cancer- Symptoms, causes, stages and treatment

Introduction

When cancerous growth of cells in the colon, it is termed colon cancer.  

Colon cancer (also known as colorectal cancer) is a common occurrence of cancer all over the world.  

It stands as the third and second most commonly diagnosed disease in males and females.  

Although middle-aged people above 50 years of age possess high risk, it affects people of all age groups.  

Colon cancer symptoms are often openly visible. Hence one can avail themselves of early diagnosis and has a better chance of fighting it.  

What is colon cancer?

The human body is made up of cells. Cells grow in our bodies through a process called cell division. 

That is, a single human cell splits up and gives birth to new cells. This process continues until old dead cells are replaced by new cells. Normally, the DNA in our cells sends a message to them when to split and when to stop. 

But sometimes, this normal function gets hampered. Cells start splitting up rapidly and give birth to new cells even when the body doesn’t require them. 

It results in the piling up of cells, which in turn grow into tumours. Whenever mutated cells start growing enormously, they form cancerous tumours. This phenomenon is called cancer. 

When such an occurrence happens in the colon, it is called colon cancer. 

The colon is a part of the large intestine. It is responsible for absorbing water and nutrients from partially digested food. 

It allows the remaining waste material and stool to pass through it to reach the rectum. From the rectum, the waste materials pass through the anal canal and eject out of the anus. 

What causes colon cancer?

Scientists are still trying to figure out the root cause of colon cancer. However, one can attain this disease either by acquiring it from outside or through inheritance. 

Hence, it is important to know the risk factors of colon cancer. Some of them are:

Family history

Having a family history of colon cancer among first-degree relatives such as father, mother or siblings as the mutated genetic information can be passed through generations. 

Colorectal polyps

Colorectal polyps are small lumps of cells developed in the colon.

The occurrence of colorectal polyps can be an early sign of cancer. 

However not all similar occurrences result in cancer, but it is advisable to get an early diagnosis when you experience this. 

Alcohol and smoking

Drinking too much alcohol regularly can increase the risk of colorectal cancer. 

Similarly, as smoking is the gateway for various kinds of diseases and disorders, it amplifies the chances of getting colon cancer. 

History of inflammatory bowel disease

When you have or have had a history of ulcerative colitis (also known as inflammatory bowel disease) for more than 8 years, you may need to consult a doctor. 

This disease causes ulcers and inflammation in the inner tract of the digestive system, which is the colon. This may sometimes result in the mutation of colon cells. 

What are the symptoms of colon cancer?

Colon cancer symptoms are often visible and are easy to identify. This allows one to go for an early diagnosis. 

Some of the common and early symptoms of colon cancer are:

• Spotting blood in the stool
• Improper bowel movements
• Stomach disorders such as diarrhea and constipation
•  Feeling of inadequate emptying of the bowel.
• Drastic weight loss
• Fatigue
• Stomach cramps and bloating

If you develop any of the listed colon cancer symptoms, consult a doctor and get a proper diagnosis and treatment. 

Diagnostic tests for colon cancer

Occult fecal blood tests

Occult fecal blood tests are performed to check the presence of blood on the samples of your feces (Stool). If your stool has blood, then it may be due to bleeding in the digestive tract. This test is also mainly performed to detect the signs of Colon cancer.  

Fecal immunochemical test

A fecal immunochemical test is basically a screening test performed to detect the presence of Colon cancer. This test helps to find the presence of blood particles in the stool which may be an indication of cancer.

Colonoscopy

Colonoscopy is an endoscopic examination used to detect abnormalities and changes in the large intestine (colon), lower bowel and rectum of the body.  

What are the various stages of colon cancer?

According to the severity of the growth of cancer cells in the colon area, colon cancer can be classified into four stages.

Stage 0

In this stage, the mutated cells are found in the innermost layer of the colon wall. This layer is called the mucosa. Here, the cancer cells may grow into nearby tissues as well. 

It is also called carcinoma in situ.

Stage 1

When cancerous cells spread from mucosa to sub-mucosa layer (lies next to the mucosa), or it moves to the muscle layer of the colon, it is classified as stage 1 colon cancer. 

Stage 2

This stage is further subdivided as follows:

Stage 2A

It is the stage where cancer moves from the muscle layer of the colon wall to the outermost layer called serosa. 

Stage 2B

Here, cancer spreads from serosa to the nearby tissues of organs in the abdomen area. This layer is called visceral peritoneum. 

Stage 2C

When cancer spreads through the serosa layer to the abdominal organs, it is categorised as stage 2C colon cancer. 

Stage 3

Like the previous stage, this stage is also sub-categorised as follows:

Stage 3A 

• In this stage, cancer has spread through mucosa and sub-mucosa layer to nearby three to six lymph nodes. 
• Or cancer has spread through mucosa to the nearby tissues of lymph nodes. 

Stage 3B

• In this stage, cancer has spread through the muscle layer to serosa and from serosa to visceral peritoneum. Abnormal cell growth is found in one to three lymph nodes or the nearby tissues or
• Cancer spreads to the muscle layer and four to six lymph nodes or
• Mutated cell growth spread through mucosa to sub-mucosa and cancer spread through more than seven lymph nodes. 

Stage 3C

• Cancer has spread to 4-6 lymph nodes. Here it spreads through the serosa to the visceral peritoneum or
• Cancer spreads through the muscle layer to serosa and visceral peritoneum. Here it spreads to more than seven lymph nodes or
• Cancer has spread to nearby abdominal organs.

Stage 4

This is considered to be the final stage, where cancer has spread to distant lymph nodes or distant organs such as the liver, ovary or lungs. 

As in the above stage, this stage is also classified into 4A, 4B or 4C based on the severity of the spread. 

What are the treatments available?

Treatment options for colon cancer depend on several factors such as health condition, age, stage of cancer, etc. They are commonly available in most places. 

Some of the treatments are:

Surgery

Oncologists often opt for surgeries if the cancer is at an earlier stage. 

They remove the tumorous cells and even the part of the colon or rectum if required. 

Chemotherapy

It is the method of using drugs to destroy cancer cells. Usually, chemotherapy is undertaken after surgery, in case of colon cancer. 

In addition to destroying cancerous cells, chemotherapy also controls the growth of cancerous cells. 

Radiation

Oncologists use radiation techniques alongside chemotherapy. This is the process in which powerful radiation is used to kill cancer cells. 

Doctors conduct chemotherapy before or after surgery if required. 

Conclusion

Colon cancer is commonly prevalent in developed countries. However, the instances of the disease are slowly growing in countries like India mainly due to the changing lifestyles. 

Some estimates show that approximately 7.2 and 5.1 per 1,00,000 males and females are exposed to colon cancer in India. But for a country with more than a billion population, this number is quite big. 

Using early diagnosis and advanced treatment options, colon cancer can be easily prevented and its occurrences can be minimised greatly.