What You Need To Know About Colon Cancer: Signs, Tests & Treatment

What You Need To Know About Colon Cancer: Signs, Tests & Treatment

Posted by Katherine Clarke on Oct 2nd 2017

There are different types of cancers that continue to plague people from different parts of the world. Researchers are continually finding ways on how to reduce the risk and completely combat these health conditions. In this article, we will learn more about colon cancer

What is Colon Cancer?

Colon cancer happens when tumorous growths develop in the large intestine. It arose as the third most common cause of cancer-related death in the U.S. in 2017 for both men and women.

According to the American Cancer Society, more than 95,000 new cases of colon cancer and close to 40,000 cases of rectal cancer each year. Rectal cancer is caused by growths that originated from or close to the rectum.

The colon or large intestine is where the body extracts water and salt from solid wastes. The waste moves through the rectum then exits the body through the anus.

Colon cancer is likely to develop when extreme cell growth occurs in the large intestines. Most colon cancer originates from noncancerous or benign tumors. These are called adenomatous polyps that form on the inner walls of the large intestine.

These cancerous cells may spread and invade healthy tissues nearby and throughout the body. This process is called metastasis. Once this occurs, circumstances may become more serious and may have a lower chance of being treated.

The risk of developing colorectal cancer is about 1 in 21 for men and 1 in 23 for women.

Colorectal cancer is expected to cause more than 50,000 deaths in 2017 in the U.S. alone. The death rate has slowly been declining since colorectal polyps are now being diagnosed early due to screening and are immediately removed before the polyps develop into cancers.

Additionally, treatment for colorectal cancer has greatly improved over the last few decades. As a result, there are now more than 1 million colon cancer survivors in the United States.

Causes of Colon Cancer

There are certain factors that put one at risk of developing colorectal cancer. However, it is still unclear to exactly identify how all these factors might cause a person to develop cancer.

Cancer is caused by the changes in the DNA inside our body. DNA is responsible for our genetic composition, which controls how our cells function. These genes help control our cell growth, which divided into new cells, some of which die. Certain genes, however, help grow, divide and remain alive. These are called oncogenes.

Cancer is the result caused by DNA mutations that turn on oncogenes or tumor-suppressing genes, which will eventually lead cells to grow in inappropriate quantity. These changes may result in colorectal cancer.

Inherited Gene Mutation

DNA mutation may be passed from generation to generation. When this occurs, mutations are inherited. A small portion of colorectal cancer is caused by inherited gene mutations.

Lynch syndrome (hereditary non-polyposis colon cancer, or HNPCC)

This is an inherited disorder that increases the risk of developing many types of cancer, particularly colon cancer. Its risk is caused by an autosomal dominant pattern, which means that one copy of the altered or mutated gene is sufficient to increase the risk of developing cancer.

Familial adenomatous polyposis (FAP) and Gardner syndrome

These are non-cancerous tumors that may form in many organs. The APC (adenomatous polyposis coli) gene is linked to the Gardner syndrome. The mutation in the APC gene gives the person a lifetime risk of developing polyps, benign tumors, and cancer.

Peutz-Jeghers syndrome

This is an autosomal dominant inherited disorder that is characterized by the intestinal hamartomatous polyps in association with a distinct pattern of mucosal and skin melanin deposition. This is caused by the inherent changes in the STK11 gene, which is a tumor-suppressor gene.

MUTYH-associated polyposis

This is caused by the biallelic pathogenic variants in MUTYH.

Acquired Gene Mutation

It is also possible that gene mutations can happen during a person’s lifetime, but are not passed on to the next generation. They only affect the cells that come from the original mutated cells.

The cause of these mutations that have caused colorectal cancer is still unknown. The increase in growth of colorectal cells may be due to the loss of this “brake” on cell growth. Further mutations may eventually occur in genes such as KRAS, TP53, and SMAD4. When these changes occur, it can lead the cells to grow and spread uncontrollably.

Signs and Symptoms

Most of the symptoms associated with colon cancer can be caused by something that is not related to colon cancer itself, such as infection, irritable bowel syndrome or hemorrhoids.

  • A feeling that you need to have a bowel movement that is not relieved by doing so
  • Change in bowel habits, such as diarrhea, constipation, or narrowing of the stool, that lasts for more than a few days
  • Cramping or abdominal pain
  • Dark stools, or blood in the stool
  • Rectal bleeding
  • Unexplained weight loss
  • Weakness and fatigue

These symptoms may be similar to other diseases, Therefore, to be certain of whatever medical condition you may be having, immediately consult your doctor so that proper care and treatment can be initiated as soon as possible.


Today’s technology has allowed us to be more aware of our condition so that we can undergo treatment right away. In the case of colon cancer detection, testing kits are available to detect DNA gene mutations, which may eventually lead to the development of cancer.

This kind of test kit is able to identify your risk for 25 hereditary cancers by being able to analyze 98 genes from your DNA. The product makes use of a sample of saliva, which is placed in a tiny receptacle that is shipped to a laboratory. The results are then mailed after three weeks.

The best way to be accurate in determining the existence of colon cancer is through undergoing a screening. Most colon cancers do not manifest symptoms until it has reached the advanced stage. The American Cancer Society recommends that colon screening should start at the age of 50.

Individuals with a family history of the disease or have other risk factors should talk with their doctors about screening at a younger age. There are several tests that can be used to screen for colon cancer. It is recommended to ask the doctor to find out which tests might be appropriate for you.

When colon cancer is detected early before it has spread, the survival rate is high. It means that early detection of any disease, for that matter, increases the chances of the person of surviving cancer.


When your doctor finds several symptoms, which may be associated with colon cancer, your doctor will recommend going through a series of exams and tests to find the cause of these symptoms.

Complete medical history should be taken to check for symptoms and risk factors, which include family history. About 1 in 5 people who develop colon cancer have other family members who also have the same condition. Meanwhile, recent studies show that a number of people were diagnosed with cancer even without family history.

Other colon problems may put an individual at risk of developing colon cancer, such as Crohn’s disease, precancerous syndromes, ulcerative colitis, and hereditary syndromes such as familial adenomatous polyposis, or hereditary non-polyposis colon cancer or Lynch syndrome. Individuals who have Type 2 diabetes can also experience a higher risk of developing colon cancer.

A physical exam will be performed by carefully feeling your abdomen as well as the rest of your body. Blood tests may also help determine the presence of colon cancer.

Colonoscopy, x-ray, or CT scan of your colon are helpful diagnostic tools, which can be used to determine the presence of any colon anomaly.

Any abnormality found through colonoscopy will require a biopsy of the affected area in the colon. A biopsy is done by taking small pieces of tissue with a special instrument that passes through a scope. The biopsy samples are then examined under a microscope to detect the presence of cancer cells.

If the diagnosis is positive for colon cancer, the treatment will be immediately initiated. However, the kind of treatment will depend on how early it has been found. Treatment may include chemotherapy, surgery, radiation, and targeted therapies.

When taking the medical history, it is important that the patient should be honest in telling about everything that the doctor asks about. If you have questions regarding the condition, never hesitate to ask your doctor about it.

Colorectal Cancer Stages

After the doctor finds out if the patient is positive for colorectal cancer, doctors will figure out whether the cancer has spread to other parts of the body or how or how far it has spread. This process is called staging. Cancer stages describe the extent of cancer in the body.

Being able to identify the stage will allow the doctor to know which kind of treatment will be given to the patient. To be able to determine the stage of cancer, doctors need to know the following:

  • Extent of growth of cancer into the wall of the intestines
  • Extent of growth to nearby structures
  • Extent of growth to nearby lymph nodes or to distant organs
Stages Description
0 The cancer is in its earliest stage, also known as carcinoma in situ, whereby the cancer has not grown beyond the inner layer of the mucosal lining of the colon or rectum.
I The cancer may have grown into the muscularis mucosa into the submucosa and it may have grown into the muscularis propia, and has not grown beyond any nearby lymph nodes or distant organs.
II The cancer has grown into the outermost layers of the colon or rectum but has not gone through them, and has not grown beyond any nearby lymph nodes or distant organs.
III The cancer has grown through the mucosa into the submucosa, and it may also have grown into the muscularis propria. It has spread to 1 to 3 nearby lymph nodes or into areas of fat near the lymph nodes but not the nodes themselves. It has not spread to distant sites.
IV The cancer may or may not have grown through the wall of the colon or rectum. It might or might not have spread to nearby lymph nodes. It has spread to 1 distant organ (such as the liver, lung or kidney) or distant set of lymph nodes.

Colorectal Cancer Grades

Another factor that can affect cancer treatment and your outlook is the grade of the cancer. The grade describes how closely the cancer looks like normal tissues when viewed under the microscope. The scale used for grading colorectal cancers is from 1 to 4.

  • Grade 1 (G1): cancer looks much like normal colorectal tissue
  • Grade 4 (G4): cancer looks very abnormal
  • Grades 2 and 3 (G2 and G3) - fall somewhere in between

The grade is further simplified as either low grade (G1 or G2) or high grade (G3 or G4).

Low-grade cancers tend to grow and spread more slowly than high-grade cancers. Therefore, the outlook is better for low-grade cancers than it is for high-grade cancers of the same stage.

There are several cancer treatments, which will be dependent on the stage of cancer of the patient. However, by using the cancer grade system, this would allow doctors to help decide if the patient may need additional treatment with chemotherapy after surgery has been performed.

Final Word

Prevention is better than cure. This old cliché makes it more convenient for us to become healthy and be aware of the dangers or risks that we may be exposed to.

Being able to adopt a healthy lifestyle as well as undergoing screening for people who are at high risk of developing cancer is a must. Early detection means having greater chances of getting treated and being able to extend our lives.