Colorectal Cancer - Important Things To Know


We all are aware of the fact that cancer is one of the leading causes of morbidity and mortality worldwide. Worldwide, millions of individuals are diagnosed with cancer and the most prevalent cancers are lung cancer, breast cancer, and colorectal cancer. Cancer has a major impact on the health-related quality of life of an individual.

Cancer occurs when the normal cells in the human body become cancerous. There are trillions of cells in the body and all the cells have built-in rules that tell guides them about their actions. These rules are known as genes that belong to DNA and any changes in the genes can cause normal cells to become cancer cells. Primarily there are three basic differences between the normal cells and cancer cells.

 Colorectal Cancer - Important Things To Know

1. Normal cells make new cells whenever needed, but cancer cells lead to the growth of new cells before the old cells die.

2. Normal cells stay in the area they belong, whereas cancer cells can spread to other parts of the body.

3. Normal cells keep an eye on the signals, but cancer cells ignore all the signals and cause harm to the human body.

There are multiple types of cancer and colorectal cancer is a type of cancer which occurs when the cells in the colon become cancerous. The colon is a part of the digestive system, system which is responsible for breaking down food for the body to use. The large intestine in the digestive system has four parts, one is the colon. The colon is the longest part of the large intestine and the walls of the colon have four main layers, namely mucosa, submucosa, muscularis propria, and serosa.

Most often, colorectal cancer begins on the inner lining of the colon, known as polyps. In general terms, polyps can be defined as an overgrowth of the cells in the lining of the colon. All colon polyps do not become cancer, but almost all colon cancer begins in the polyp. Polyps are of two types:

  • Pedunculated polyps - This type of polyps look like a mushroom and they stick out from the colon wall.
  • Sessile polyps - This type of polyp is flatter in shape and they don’t stick much out from the colon wall.

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Symptoms Of Colon Cancer

Some of the signs and symptoms that occur in colon cancer can include:

  • Sudden change in bowel habits
  • Unexplained weight loss
  • Pain in the lower abdomen
  • Fatigue
  • Weakness

Stages Of Colon Cancer

There are total of 5 stages of colon cancer:

STAGE 0 - Cancer in this stage is known as non-invasive, means that it has not grown beyond the first layer of the colon wall. This is also known as carcinoma in situ of the colon.

STAGE 1 - Cancer in this stage has now grown into the second layer of the colon wall or into the third layer of the colon wall. At this stage, cancer has not spread to the nearby lymph nodes.

STAGE 2 - Cancer in this stage has grown into or beyond the fourth layer of the colon wall.

STAGE 3 - Cancer in this stage has spread from the colon to the nearby lymph nodes. Also, in this stage, there is a development of small tumors in the fat around the colon.

STAGE 4 -  This is the last stage of the colon cancer and in this stage, cancer has spread to other parts of the colon. Most often, it spreads to the liver and the lungs.  

Types Of Colorectal Cancer

There are several types of colorectal cancer and some of them include:


Adenocarcinomas refer to the polyp that has become cancerous and this type of cancer can spread to other parts of the body. Adenocarcinomas are the most common type of colorectal cancer and it begins as small polyps in the bowel. Most of the cases of colorectal cancer are of adenocarcinoma.


Carcinoids are slow growing cancer. There are small tumors that have the capability of producing hormones and other compounds that are active in the body. The symptoms that occur in this type of cancer depend on their location in the colorectal tract.


Gastrointestinal stromal tumors begin in the special cells in the walls of the colon, known as interstitial cells of cajal. This type of tumor can begin anywhere in the digestive tract.


Lymphomas are defined as cancer of immune system cells. Mostly, it begins in the lymph nodes of the cells, but it can also begin in the colon or rectum.

Risk Factors Of Colorectal Cancer

There are several factors that can be considered to play a role in the occurrence of colorectal cancer. Here is the list of some of the risk factors of colorectal cancer:

1. Age - Multiple researchers have demonstrated that the risk of developing colorectal cancer increases with age. It is common in people over the age of 50 and it has been observed that most often, people who are diagnosed with colorectal cancer are old.

2. Obesity - Obesity is considered to be a public health issue and it is defined as a condition in which the fat gets accumulated in the body. Obesity is associated with various complications, including colorectal cancer. The risk of developing colorectal cancer is 4 times more in obese people.

3. Diet - What we eat has an important role to play in keeping the health of an individual. People who have a diet which is high in fiber, calorie, and protein are at the risk of developing colorectal cancer.

4. Diabetes - Diabetes is a chronic disease which is characterized by the high sugar level in the blood. The blood sugar level in the body becomes too high that it starts causing harm to the body. Research has shown that people who are diabetic are more likely to suffer from colorectal cancer as compared to those who do not have diabetes.  






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