How A PET Scan Can Determine The Stage Of Colorectal Cancer

16 May 2016
 Categories: Health & Medical , Blog


Colorectal cancer is one of the most common forms of cancer that affects men and women. Around 137,000 Americans are diagnosed with colorectal cancer every year and over 50,000 die. It helps to catch this cancer early because it can spread to other parts of your body.

Most cancers are treatable when caught early. However, the stage of your cancer plays a major role in determining treatment options. Read on to find out how a PET scan can determine your stage of colorectal cancer.

What Is A Pet Scan?

A PET CT scan cancer test is used to show the progression of colorectal cancer. It creates pictures of tissues and organs inside of your body. When A PET is done, a tiny amount of radioactive sugar substance is injected into your body. This substance is absorbed by the cells that use the most energy.

Cancer uses a lot of energy, which means it would absorb more of the sugar substance. A scanner is then used to detect this substance to create pictures of the inside of your body.

How PET Is Used In Staging?

Once the cancer is diagnosed, you have to undergo testing to determine how much the disease has spread. This is called staging, which is used for determining treatment options. A variety of treatment options are used at different stages for colorectal cancer.

Staging is done at two different points when treating this disease. It is first done immediately after diagnosis. A PET scan is done of your body to find the location of the cancer and to get a look at the mass. Your doctor uses the picture created from this procedure to assign a stage.

A PET scan is used again after a cancer patient has gone through radiotherapy or chemotherapy. Staging is done after treatment to see if the tumor has responded. If so, your stage will do down to a lower level, which means you are getting better.

How Is Staging Determined?

The TNM system is one of the most common systems for staging colorectal cancer. It was established by the American Joint Committee on Cancer. This system uses three factors to determine the stages of cancer. These factors are metastasis, lymph node and tumor. 

To determine staging, your doctor will look to see how far the main tumor has grown into the wall of your rectum or colon. It is also checked to see if the tumor has spread to other areas. The next thing to look at is your lymph nodes. Your doctor will check to see if the cancer has spread to your lymph nodes and the progression. Metastasis is the term used when the cancer has spread to other parts of your body like the brain, lungs or liver.

Each factor is assigned a number from 0 – 4 or the letter X. This means that each stage has a number like Stage 0. As the number increase, it means the severity of cancer increases. After your doctor determines your TNM score, an overall stage is assigned and you can start looking into treatment options.

Being diagnosed with cancer is hard on the patient and his or her family. It is important to explore all treatment options and to keep fighting.