Five things you need to know about colorectal cancer

Colorectal cancer is the fourth most common cancer in the U.S., with more than 136,000 new patients diagnosed last year. But thanks to increased awareness about screenings, the death rate from colorectal cancer has been dropping for more than 20 years.

“For the most part, colorectal cancer is a curable and preventable disease,” said Jeffrey Meyerhardt, MD, MPH, clinical director of the Dana-Farber Gastrointestinal Cancer Treatment Center. “It is a cancer for which we have very good data that shows screening prevents disease and saves lives.”

With March marking Colorectal Cancer Awareness Month, here are the answers to some key questions about the disease:

1. What are the risk factors for colorectal cancer?

Age and gender can increase the chance of developing colorectal cancer. Other risk factors include:

A family history of colon or rectal cancer

A personal history of cancer in the colon, rectum, ovary, endometrium, or breast

A history of polyps (small pieces of bulging tissue) in the colon or rectum

A history of ulcerative colitis or Crohn’s disease

Certain hereditary conditions

Obesity

Sedentary lifestyle

Certain dietary factors, including high intake of red and processed meat

2. How do doctors screen for colerectal cancer?

Aside from a physical exam to check general signs of health, other screening options include a fecal occult blood test, a double contrast barium enema (lower GI series), a sigmoidoscopy, a colonoscopy or a virtual colonoscopy.

3. How often should you be screened?

For most patients, screening is recommended to start at age 50. However, if you have a family history or other risk factors for colorectal cancer, you should discuss with your doctor whether you should start screening earlier.

The frequency of the screening will depend on which test was used to screen, what was found, and your risk factors for colorectal cancer. It is important to know that these screening guidelines refer to patients with no concerning signs or symptoms. If you have blood in your stool, for example, you should consult with your doctor. 

4. What are the symptoms of colorectal cancer?

One of the most common signs of colorectal cancer is a change in bowel habits or blood in the stool. Others include:

Diarrhea, constipation, or feeling that the bowel does not empty completely

Stools that are narrower than usual

Frequent gas pains, bloating, fullness, or cramps

Weight loss for no known reason

Persistent tiredness

Vomiting

5. How is colorectal cancer treated?

Surgery to remove the cancer is the most common treatment for all stages of colorectal cancer. There are several different types of surgery that can be performed depending on the cancer stage and location. If surgery is not sufficient, a doctor may also decide to use chemotherapy and/or radiation therapy.

There are also several targeted therapy options for colorectal cancer, including treatment with monoclonal antibodies.