Colorectal Cancer: Updates in Screening

As of recent years, the American Cancer Society has reported that the rate of colorectal cancer among individuals younger than 50 has been increasing by 2% annually. We now see 1 in 5 cases of colorectal cancer in people between the ages of 20 and 54. It is the second deadliest cancer in the United States and third most common cancer found in women and men combined.

Even though colorectal cancer is one of the deadliest of cancers, it is also one of the most preventable. There is a huge stigma associated with the disease, body parts it affects and procedures used to diagnose it. Many individuals are embarrassed and ashamed to discuss their concerns and symptoms even during office visits to their doctor. While it may be uncomfortable, we need to normalize this dialogue in order to prevent a delay in diagnosis and treatment. 

The exact cause of colorectal cancer is unknown.  But, there are risk factors that may increase a person’s likelihood of getting the disease.  Modifiable risk factors include obesity, physical inactivity, tobacco use, diet rich in red, as well as processed, meats, and alcohol use.  Additional risk factors include; age above 50, being African American, being of Ashkenazi Jewish descent, having a family history of colorectal cancer, a personal history of Crohn’s disease or ulcerative colitis for greater than eight years, as well as being diagnosed with inherited genetic syndromes such as familial adenomatous polyposis and lynch syndrome.

Colorectal cancer often has no symptoms and is diagnosed during routine screening. However, a small portion of those affected can experience a few of the following symptoms:  a change in bowel habits (constipation or diarrhea), narrow shaped stools, bloody bowel movements, lower abdominal or pelvic pain, fatigue, nausea or vomiting and unexplained weight loss.

It is important to note that some common health problems can also cause the above-mentioned symptoms such as hemorrhoids causing rectal bleeding, which does not cause cancer. Therefore, it is extremely imperative to mention any symptoms you may be having to your primary care doctor in order to ensure proper workup and treatment.

Screening is the process of identifying cancer in individuals who have no symptoms. The likelihood of surviving colorectal cancer is largely dependent on when it is detected. If diagnosed in the earlier stages, approximately 90% of individuals survive for five years or longer. But, if it is detected later, in more advanced stages, the five-year survival rate across all races is as low as 14%. Thus, it is extremely important to follow recommended screening guidelines performed in a timely manner. For those at an average-risk for developing colorectal cancer, it was previously recommended to start screening at the age of 50. But, recently guidelines set forth by the United States Preventive Services Task Force recommend starting at the age of 45.      

Current screening modalities can be divided into two main groups: stool-based tests and visual examinations. Stool-based tests check feces for signs of cancer. These tests are less invasive, can be performed in the comfort of your home without needing any bowel prep, but need to be done more often. The fecal immunochemical test (FIT) checks for blood hidden in stool from the lower GI tract and does not require any drug or dietary restrictions prior to testing. The guaiac-based fecal occult blood test (gFOBT) works differently than FIT and searches for hidden blood in stool through a chemical reaction. Therefore, some foods (i.e. red meats, Vitamin C) and medications (i.e. aspirin, ibuprofen) may interfere with the results of this test and will need to be held prior to testing. Both the FIT and gFOBT need to be performed yearly. Lastly, a stool DNA test, known as Cologuard, looks for abnormal sections of DNA from cancer cells as well as hidden blood. This test should be done every 3 years and does not require any dietary or medication restrictions prior to testing. If any of the three stool tests mentioned above are abnormal, they must be followed up by a colonoscopy.

Under the next category of screening modalities are visual examinations, which include colonoscopy, CT colonography (also known as virtual colonoscopy), and flexible sigmoidoscopy. All three of these exams can be performed less frequently than stool testing, but require bowel preparation prior to the test. During a colonoscopy, while under sedation, a doctor uses a flexible scope to look through the entire length of the colon and rectum to search for any suspicious masses and take biopsies, if necessary. If the examination is normal, a follow-up colonoscopy is recommended ten years later. A CT colonography uses an advanced CT scan to create 3D images of the colon and rectum. It is less invasive than a colonoscopy and does not require any sedation; however, still requires bowel prep prior. If there are any concerning areas noted, a colonoscopy will still be needed to remove the worrisome masses and to thoroughly investigate the area.  A flexible sigmoidoscopy is similar to a colonoscopy, but it only examines the rectum and about half of the colon due to the scope being approximately 2 feet long.  It is not widely recommended as a screening tool in the United States as it does not view the entire colon.      

As you can see, there are a few screening modalities besides just a colonoscopy. It is important to discuss with your primary care physician which method would be the best for you.

For more information for you or your loved ones, please contact your primary care physician. Dr. Ruby Jhaj is currently accepting patients and may be reached at
760-995-2099.