Colon cancer is cancer that affects the colon. You can have only colon cancer, and it may be considered a type of colorectal cancer.
Colorectal cancer (CRC) is a type of cancer that impacts your large intestine. Excluding skin cancer, it’s the third most common type of cancer in the United States, according to the
You may be curious whether or not CRC is the same thing as colon cancer. While there’s overlap between the two conditions, there are some differences to be aware of. Keep reading to discover more.
Overall, colon cancer falls under the umbrella of CRC. To better understand this, it’s important to know just a little bit about the large intestine.
The function of your large intestine is to absorb water and electrolytes from the food that you eat. What’s left over is expelled from the body as stool.
The main part of the large intestine is the colon, which is about 5 feet long. This is the part of your large intestine that absorbs water and electrolytes from your food.
The last 6 inches or so of your large intestine is called the rectum. Leftover waste material is stored here until it’s eliminated through the anus during a bowel movement.
Simply put, CRC is cancer that starts in the colon or in the rectum. Colon cancer is cancer that starts in the colon only. Colon and rectal cancers are often grouped together as CRC because they share many features.
CRC starts either in the colon or in the rectum. The
The symptoms of CRC include:
- blood in your stool
- rectal bleeding
- abdominal pain or discomfort
- a change in your bowel habits such as:
- diarrhea or constipation that lasts longer than several days
- stool that’s very stringy
- feeling like your bowels aren’t empty after having a bowel movement
- decreased appetite
- unintentional weight loss
CRC has a strong genetic component. In fact, it’s estimated that
In addition to genetic factors, other risk factors for developing CRC include:
- older age
- a personal history of high risk polyps or CRC
- being African American, which may be because of inequalities in socioeconomic status and access to healthcare
- having certain conditions such as:
- overweight or obesity
- a diet high in red or processed meats
- heavy alcohol use
- low levels of physical activity
Colon cancer starts in the colon only. According to the
Because it falls under the umbrella of CRC, colon cancer has significant overlap with CRC in many of its qualities. However, there are some subtle differences.
For example, low physical activity levels are a risk factor for colon cancer but not for rectal cancer. The association between red or processed meat consumption and cancer risk is also
Those with a colon cancer diagnosis are
Colon cancer is also
CRC and colon cancer both use treatments such as:
- radiation therapy
- targeted therapy
However, there are variations in treatment, especially where surgery is concerned. This is because the type and extent of the surgery that’s used can depend on whether the cancer is in the colon or the rectum.
Very early tumors that haven’t yet grown beyond the lining of the colon or rectum can often be removed using a polypectomy or local excision. This involves cutting out the area with the cancer during a colonoscopy.
When colon cancer or rectal cancer has spread further, additional surgery may be needed. This is where things start to get different.
Surgery for colon vs. rectal tumors
For colon cancer, partial colectomy is used for larger or more advanced cancers. This is when a surgeon removes the area of the colon with the cancer. Surrounding lymph nodes may be removed as well.
Sometimes, the surgeon is able to reconnect the cut ends of the colon. This is called anastomosis. If this isn’t possible, an opening is made in your abdomen that allows stool to pass into a bag outside of your body. This is called colostomy.
For larger or more advanced rectal cancer, surgery can include a variety of procedures, depending on the exact location and size of the cancer. These procedures include:
- Transanal surgery: Smaller rectal tumors that aren’t far from the opening of the anus can be removed through the anus. This procedure doesn’t require an incision in your abdomen. Types of transanal surgery include:
- transanal excision
- transanal endoscopic microsurgery
- Resection: Larger or more advanced rectal tumors are typically removed using resection. This can involve several types of procedures such as:
- low anterior resection, which involves removing the area of the rectum that has the cancer
- proctectomy with colo-anal anastomosis, which is the removal of the whole rectum and the creation of a small pouch from the end of the colon to help store stool
- abdominoperineal resection, which is the removal of the rectum, anus, anal sphincter, and other nearby tissues
Sometimes chemotherapy is given before or after surgery for colon cancer. For rectal cancer, radiation therapy is often given along with chemotherapy before or after surgery. This is called chemoradiation.
When these treatments are given prior to surgery to help shrink a tumor, it’s called neoadjuvant therapy. When they’re given after surgery to kill any cancer cells that may remain and help prevent a recurrence, it’s called adjuvant therapy.
If CRC or colon cancer has spread to more distant areas, tumors may still be able to be removed using surgery. However, if these tumors are large in size or number, a treatment such as targeted therapy or immunotherapy may be used.
Surgery for CRC or colon cancer can come with a variety of risks. Some that are shared between the two conditions are:
- bleeding at or around the surgical site
- blood clots
- scar tissue in the abdomen called adhesions
In surgery for colon cancer where anastomosis was done, it’s possible that there may be a leak where the two ends of the colon were sewn together. When this occurs, another procedure may be needed to repair the leak.
It’s also possible that it may take time for the smooth muscles in your colon to start contracting again. This is called ileus and typically gets better over time, although you may need to stop eating and get fluids by IV for a period of time.
Surgery for CRC and colon cancer is also associated with a variety of bowel changes, which may include:
- more frequent bowel movements
- bowel movements that come on with little warning
- diarrhea or constipation
- trouble emptying your bowel completely during a bowel movement
- increased bloating or gassiness
These changes may last for several weeks or months after your surgery but generally improve over time.
Below, we’ll answer some other questions that you may have about CRC and colon cancer.
Can CRC and colon cancer be prevented?
There’s no surefire way to prevent either type of cancer. However, there are some things that you can do to help lower your risk such as:
- taking steps to manage your weight, if necessary
- lowering your consumption of red or processed meats
- quitting smoking
- drinking alcohol in moderation or not at all
- making sure to get regular exercise
Who should be screened for colorectal and colon cancer?
Those at a higher risk may need to have a doctor start screening for CRC and colon cancer earlier. This includes people with inherited genetic syndromes that increase risk as well as those with a strong personal or family history of high risk polyps, CRC, or colon cancer.
Can colorectal or colon cancer be cured?
Both CRC and colon cancer are highly treatable when they’re found early. In situations where cancer is small and remains localized to the colon or rectum, it may be possible to cure the cancer.
Can colorectal or colon cancer spread?
Yes. When cancer spreads to more distant areas of the body, it’s called metastasis.
CRC and colon cancer have similar common metastatic sites. According to the
Can colorectal or colon cancer come back?
Yes. If cancer comes back after treatment, it’s called a recurrence. Recurrence rates and time to recurrence are pretty similar between CRC and colon cancer.
Previous research has found that CRC recurs in 20 to 30% of people. About
Researchers have estimated that
CRC is cancer that starts in the colon or the rectum. Meanwhile, colon cancer is cancer that begins in the colon.
Colon cancer is generally placed under the umbrella of CRC. This is because colon cancer and rectal cancer have a large amount of overlap both biologically and in qualities such as symptoms and risk factors.
There are some differences between CRC and colon cancer, especially when it comes to surgical treatments. This is because the type of surgery that’s used can depend on if the cancer is in the colon or the rectum.
The outlook for people with either cancer is best when the cancer is found early. Screening can help find tumors early, so it’s important to talk with a doctor about when screening should start and what type of test is recommended for you.