Colorectal Cancer Screening: a New Study Questions the Effectiveness of Colonoscopies But Specialists Reinforce its Importance

Nevertheless, several experts say that as good as this study was, it has important limitations, and these results shouldn't deter people from getting colonoscopies.

Dr. Jennifer Watters, an attending surgeon at St. Charles Health System in Oregon, shared a breathtaking personal experience with SurvivorNet.

“My aunt was diagnosed with colon cancer in her late 40s and died less than a decade later after multiple operations and adjuvant therapy. Because of her I had my first colonoscopy at age 40. At that time I had a 1 cm pre-cancerous polyp. On every subsequent colonoscopy I've had pre-cancerous polyps, removed again. I walk out of that procedure feeling like I am on top of the world, a new lease on life having kicked cancer to the curb before it even got started.”

NordICC Study: What’s all the fuss about?

The study collected data from around 84,000 adult patients in Poland, Norway, and Sweden. Researchers randomly selected about 28,000 adults to undergo colonoscopies and compared colon cancer diagnoses and deaths with a randomly selected control group of about 56,000 people who didn't get these screenings.

Over a median follow-up period of 10 years, there were 259 cases of colon cancer detected in the group invited to get colonoscopies and 622 cases in the control group. At 10 years, the group invited to get colonoscopies had an 18% lower risk of colon cancer and a 10% lower risk of death from these tumors than the group that didn't get screened.

These results come as a shock since many other studies had shown getting a colonoscopy reduced the odds of dying of colon cancer by 70%.

Colorectal cancer surgeon Dr. Heather Yeo explains why it’s important that everyone follow colon cancer screening guidelines. 

Results need careful interpretation

The Society of American Gastrointestinal Endoscopic Surgeons (SAGES) represents more than 6,000 surgeons and endoscopists who care for patients with GI diseases, including colon cancer. Just after the study was released and several provocative headlines and commentaries were published, SAGES released a note hoping to clarify the results of the NordICC study.

“SAGES affirms the value of colonoscopy in the prevention, identification, and treatment of colorectal cancer based on the preponderance of evidence. We urge the public to follow the guidelines for screening to prevent colon cancer. We also advocate for the insurance industry to maintain coverage for screening colonoscopy to ensure equitable access to care and maintain the standard for public health.”

According to the society, the results must be interpreted with caution considering the significant design limitations of the study.  Among patients who received an invitation to undergo screening, only 42% complied with the study protocol and underwent colonoscopy. That significantly diluted the impact of screening colonoscopy on reducing colorectal cancer incidence and cancer-related mortality.

SAGES declared that the lower-than-expected benefits, especially as it relates to reducing cancer-related mortality, should not impact national recommendations regarding colorectal cancer screening.  They reinforce that colonoscopy remains the most effective screening test to identify and reduce the incidence of colorectal cancer.

The American College of Surgeons (ACS) also commented on European study. They firmly endorsed the value of colonoscopy screening guidelines and practice as performed in the United States and reiterated the importance of screenings to prevent and detect cancer early.

“It is clear that patient outcomes are vastly improved when cancer is detected early," said ACS Executive Director & CEO, Patricia L. Turner, MD, MBA, FACS. "The value and importance of colonoscopies in preventing and detecting colorectal cancer cannot be overstated, and current U.S. guidelines are based on decades of research in the United States showing that routine screenings with colonoscopy can save lives."

About the American College of Surgeons

ACS is a scientific and educational organization of surgeons that was founded in 1913 to raise the standards of surgical practice and improve the quality of care for all surgical patients. The College is dedicated to the ethical and competent practice of surgery. Its achievements have significantly influenced the course of scientific surgery in America and have established it as an important advocate for all surgical patients. The College has more than 84,000 members and is the largest organization of surgeons in the world

Colorectal Cancer Screening

A screening test is used to look for a disease when a person doesn't have symptoms (when a person has symptoms, diagnostic tests are used to find out the cause of the symptoms).

The Centers for Disease Control and Prevention (CDC) and the U.S. Preventive Services Task Force recommend that adults age 45 to 75 be screened for colorectal cancer. Patients with other risk factors such as family history may benefit from earlier screening. Colonoscopy for screening in average risk patients was approved by CMS for Medicare beneficiaries in 2000 and is almost universally covered by most private insurance carriers.

Alternatives to Colonoscopies

Colonoscopy is the gold standard when it comes to detecting and preventing colorectal cancer, especially for those with a family history of colon cancer or a history of inflammatory bowel disease. But while it's the best preventive method, many people hesitate to have a colonoscopy often fearing the test preparation or the invasiveness of the procedure.

There are colon cancer screening tests available:

• Fecal occult blood test: fecal occult blood test involves analyzing a stool sample (poop), for blood. Occult blood means that you can’t see it with the naked eye. Occult blood in the stool may indicate colon cancer or polyps in the colon or rectum though not all cancers or polyps bleed. One of the most performed tests is the guaiac-based fecal occult blood test (gFOBT). It uses the chemical guaiac to detect blood in the stool and it has to be done once a year.
• Fecal immunochemical test (FIT): it uses antibodies to detect blood in the stool and it’s also done once a year.
• Stool DNA test: this test checks for blood and specific DNA in a stool sample, which could indicate the presence of colon cancer.
• Virtual colonoscopy (CT colonography): virtual colonoscopy is a special X-ray examination of the colon using low dose computed tomography. The procedure does not require sedation. However, as with colonoscopy, a person will need to use medications or an enema to clear the colon beforehand. During the procedure, a healthcare professional will inflate the colon with air to provide a better view.

You and your doctor should decide on the method of screening based on a discussion of the benefits of each technique, its possible complications, costs, availability and individual's preference.

Colorectal cancer

Colon cancer is a type of cancer that affects your large intestine (colon) or the end of your intestine (rectum). Your doctor might call this type of cancer colorectal cancer. It’s is one of the most common cancers worldwide. In the United States, 147,000 individuals received a diagnosis of the disease in 2020, and 53,200 died from it.

• Most patients with colorectal cancer are older than 50 years of age at diagnosis.
• Men have a higher risk than do women.

Most colorectal cancers develop from benign polyps (abnormal lumps) through a series of genetic changes that take 10 – 15 years. Polyps are very common: about half of individuals 50 years of age and older have polyps.

Detection and removal of colorectal polyps by colonoscopy hinders progression to colorectal cancer. Because only individuals who get a disease can die from it, the reduction of colorectal cancer incidence by adenoma detection and removal through screening leads to reduced mortality associated with colorectal cancer. In addition, screening may detect cancers at an early stage and thereby reduce mortality.

In order to better understand the disease, SurvivorNet has put together a list of colon-cancer-related terms to help you or a loved one should a diagnosis arise. Furthermore, we know that the diagnosis of a cancer can be overwhelming. So we created a specific page with several questions you should ask your doctor.

Questions to Ask Your Doctor

• Do I need to get a screening test for colorectal cancer?
• What screening test(s) do you recommend for me? Why?
• How do I prepare?
• Do I need to change my diet or my usual medication before taking the test?
• Will it be uncomfortable or painful?

Learn more about SurvivorNet's rigorous medical review process.

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