Montgomery Medicine No. 788

Colorectal Cancer Screening

Screening for colorectal cancer (CRC) has become increasingly common thanks to growing public awareness and campaigns like the CDC’s Screen for Life Action Campaign. Each year, over 150,000 new cases of CRC are diagnosed, and about 53,000 people die from the disease. This makes CRC the third deadliest cancer in men, after lung and prostate cancers, and in women, after lung and breast cancers. The good news is that when CRC is caught early, while still localized to the colon, 90 percent of patients survive for at least five years. Unfortunately, only 39 percent of cases are diagnosed at this early stage.

Over the past decade, the rates of new CRC cases and deaths have stabilized, likely due to improved screening practices and possibly other factors. However, a concerning trend has emerged: CRC is increasingly being diagnosed in younger individuals. Between 2012 and 2016, new cases of CRC in people under 50 rose by more than 2 percent annually. Actor Chadwick Boseman, for example, tragically passed away from CRC at just 42 years old.

Recognizing the warning signs of CRC is crucial. These include blood in the stool, persistent abdominal pain, changes in bowel habits (such as narrower stools), unexplained weight loss, and iron-deficiency anemia. However, CRC often presents without symptoms in its early stages. A memorable New York Times advertisement once highlighted this fact with the message: “You feel great; You have a healthy appetite; You’re only 50.” This served as a powerful reminder that feeling healthy doesn’t mean CRC isn’t a possibility.

Age is the most significant risk factor for CRC, with 93 percent of cases occurring after age 50. A family history of CRC or colon polyps increases the risk, but it’s important to note that 75 percent of cases occur in people without a family history. Other risk factors include inflammatory bowel diseases like Crohn’s disease and ulcerative colitis, lack of regular exercise, diets high in fat and low in fiber, smoking, obesity, and excessive alcohol consumption.

CRC typically begins as small clusters of abnormal cells in the colon’s lining. These cells may develop into polyps, which are finger-like growths inside the colon. While most polyps are not cancerous, adenomatous polyps have the potential to become cancerous over time. Hyperplastic polyps, on the other hand, do not carry this risk.

The primary goal of CRC screening is to identify abnormal cells before they turn cancerous or to detect cancer when it is still small and treatable. Several screening methods are available, and recommendations vary among professional groups. Tests that can detect adenomatous polyps and cancer include flexible sigmoidoscopy, colonoscopy, double-contrast barium enema, and virtual colonoscopy. Both flexible sigmoidoscopy and colonoscopy offer the added advantage of allowing physicians to biopsy and remove polyps or suspicious lesions during the procedure. Colonoscopy is considered the gold standard for CRC detection, but some patients are hesitant due to the prep and its invasive nature.

Less invasive screening options include high-sensitivity fecal occult blood testing (FOBT) and fecal immunochemical testing (FIT). FOBT requires dietary restrictions and multiple stool samples, which has made it less popular over time. FIT, which has largely replaced FOBT, is more convenient as it doesn’t require dietary restrictions and only needs a single stool sample. Additionally, FIT specifically detects human blood proteins, reducing the likelihood of false positives caused by dietary factors. However, if either test yields a positive result, a colonoscopy is typically recommended to locate the source of bleeding.

The newest screening tool, Cologuard®, combines FIT with a DNA test for cancer-specific markers. While promising, it has a higher false positive rate (13 percent) compared to FIT alone (5 percent). Despite these limitations, Cologuard® offers another option for those hesitant to undergo traditional screening methods.

If you’re over 45 or have other risk factors, it’s essential to discuss CRC screening options with your health care provider. The United States Preventive Services Task Force recommends CRC screening for individuals aged 50 to 75, giving it their highest “Grade A” rating. It also recommends starting screening at age 45, with a “Grade B” rating. Screening for those over 75 is generally not advised unless specific circumstances warrant it.

Thanks to the Affordable Care Act, insurance companies must cover recommended CRC screenings without requiring patients to pay co-pays or deductibles. However, if a procedure like a colonoscopy results in the removal of a polyp, patients may incur additional costs for the biopsy and pathology.

For more information, visit bit.ly/41s99Wg to access the latest Colorectal Cancer Facts & Figures.