What is colorectal adenocarcinoma?

Colorectal adenocarcinoma is a type of cancer that starts in the large intestine. Colorectal stands for your colon and rectum, which make up the large intestine. There are different types of colon and rectal cancer, but adenocarcinoma is the most common. When doctors talk about colon cancer, they are usually talking about colorectal adenocarcinoma.

Common related conditions
Colorectal Cancer Gastrointestinal Carcinoid Tumor

Causes of colorectal adenocarcinoma

It's not clear what causes colorectal adenocarcinoma, but researchers do know that changes — or mutations — in your cells' DNA can cause cancer. DNA makes up your genes, and genes give you traits, such as how you look. DNA is passed down to you from your parents.

For colon cancer to form, many different genes need to mutate. The two types of gene mutations that affect colon cancer are:

  • Inherited gene mutations — these pass from one generation to the next; they cause a small number of cases of colorectal cancer.
  • Acquired gene mutations — these mutations are not related to family genes, they happen during a person's lifetime.

Acquired gene mutations cause most cases of colorectal adenocarcinoma.

Risk factors of colorectal adenocarcinoma

Certain conditions make a person more likely to develop colorectal adenocarcinoma. The group of people at highest risk is women who are age 50 years or older. African-Americans have the highest risk among all races in the US.

Additional risk factors include:

  • Smoking
  • Having type 2 diabetes
  • Not getting enough exercise
  • Obesity or being overweight
  • Drinking too much alcohol
  • Inheriting gene mutations
  • A diet high in fat and low in fiber
  • Family history of colorectal cancer
  • Eating too much red meat and processed meats
  • Having ulcerative colitis (a disease in the bowels)
  • Having colon polyps (masses of cells like a tumor in the colon)

Symptoms of colorectal adenocarcinoma

When colon cancer is in its early stages, you may not have any symptoms.

It's important to see your doctor if you do begin to see any of these symptoms that won't go away:

  • Pain in your abdomen
  • Unexplained tiredness or weakness
  • Losing weight for an unknown reason
  • Blood in your stool or bleeding from your rectum
  • A full feeling in your bowels even after you've had a bowel movement
  • Changes in your bowel habits such as constipation, diarrhea or narrow stools

Diagnosis of colorectal adenocarcinoma

Fortunately, screening tests for colorectal cancer exist. This means if you have high risk factors but might not have symptoms, you can take a test.

Doctors recommend regular screening tests to avoid colon polyps developing into cancer. It takes 10 to 15 years for a colon polyp to become cancer and early screening can prevent this.

If you do have symptoms, or if the screening test shows possible colorectal cancer, you'll have more tests. These tests help your doctor know if you have colorectal adenocarcinoma:

  • Blood tests — the doctor looks for certain signs related to your liver, kidney, blood count and other factors for the possibility of colon cancer.
  • Colonoscopy — a thin tube with a camera on the end is put in the rectum and colon, the doctor looks for polyps or other unusual areas.
  • Biopsy — a small piece of tissue from your colon or rectum is removed and tested for cancer at a lab.
  • Imaging — imaging tests such as x-rays, ultrasound, MRI and PET/CT scans take pictures of your colorectal area looking for any polyps or odd looking areas.

Treatments for colorectal adenocarcinoma

The three main ways to treat colon cancer are:

The type of surgery you have depends on how far along the colorectal adenocarcinoma is. Perhaps a polyp is removed during a colonoscopy. A more serious surgery removes part of your colon to get rid of the cancer.

This treatment uses drugs to kill cancer cells. Chemotherapy is sometimes used before surgery to make the cancer smaller. It is also used after surgery to keep it from coming back.

Radiation therapy
Powerful electronic rays kill the cancer cells. It is also sometimes used before or after surgery.

Your doctor might also recommend certain drugs to take, called targeted drug therapy. Immunotherapy is another treatment choice, which uses antibodies to attack the cancer cells.

Recovery from colorectal adenocarcinoma

After treatment, your doctor will help you cope with the side effects and have healthy habits.

The most important goal is to keep the colorectal adenocarcinoma from coming back. Have regular checkups with your doctor and follow their instructions for taking care of yourself. Keep an eye out for the symptoms of colon cancer too.

In addition, remove the risk factors that you have control over like smoking, drinking and eating habits.

Find a colorectal cancer specialist nearby

Mercy Health locations that can treat you