Your Comprehensive Guide to Colon Cancer

Everything you need to know about the third most common cancer in the U.S., including risk factors for the disease and colon cancer prevention, according to experts.

Exactly How to Prevent Colon Cancer
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Nearly a year ago in August 2020, Chadwick Boseman passed away due to complications from colon cancer, sending a veritable shock wave through many households. Suddenly, seemingly everyone wanted to know more about the actor's condition or, more specifically, colon cancer: a disease that's often not on the radar of younger adults. (Boseman was 39 years old when diagnosed, and died just four years later.) While colon cancer does most frequently occur in people older than 50, rates of the disease in younger adults have skyrocketed during recent years. And get this: Those born around 1990 have twice the risk for colon cancer compared to those born around 1950, according to the American Cancer Society. The verdict's still out on the specific reason(s) for this boom, but lifestyle factors (e.g. diet) and environmental exposures (e.g. food additives) might be to blame.

Know, though, that colon cancer is fairly "preventable with the proper education and screening," says Valery Muenyi, M.D., a gastroenterologist and hepatologist at Digestive Disease Consultants in Jacksonville, Florida. Learn more about the common type of cancer as experts break down everything you need to know about the disease, including signs, symptoms, and how to prevent colon cancer.

What Is Colon Cancer and Its Symptoms?

Also known as colorectal cancer, colon cancer is a disease in which cells in the lining of the colon or rectum grow and multiply uncontrollably, according to the Centers for Disease Control and Prevention. (Slept through biology 101? A quick refresher: The colon and rectum are parts of the large intestine that play crucial roles in digestion, nutrient absorption, fluid reabsorption, and elimination of waste. Food — or soon-to-be waste — moves from the small intestine to the large intestine, where it first passes through the colon and then into the rectum. Think of the rectum as the last stop on the train before waste is expelled out of your tush.)

Though not true in all cases of the condition, colon cancer often develops from small, abnormal growths known as polyps that form in the colon or rectum. These potentially precancerous polyps, however, can be easily detected and removed via screening tests (e.g. colonoscopy) before they turn into cancer. Whether brought on by such growths or a slew of other causes (more on these below), colon cancer can easily go undetected — at least initially. That's because the disease doesn't necessarily cause symptoms right away and when it does, they can be very similar to those caused by other problems (e.g. IBD, IBS, hemorrhoids), according to the American Cancer Society.

So, what do the common colon cancer symptoms include? Abnormal changes in stool frequency or consistency, bloody stools, chronic bloating, abdominal pain, cramping, nausea, vomiting, unintentional and rapid weight loss, rectal bleeding, or anemia. Patients might also experience low energy, fatigue, and urgency to poop but not feeling relieved after doing so, according to the American Cancer Society. Just because you might suffer from, say, bloating, cramping, and bloody stools, however, does not mean you necessarily have colon cancer. Again, because many colon cancer symptoms overlap with those of other digestive diseases, so it's best to consult a doctor to determine what exactly is going on in your gut. (It's also just another reason why regular colonoscopies and other screenings are so important.)

Colon Cancer Risk Factors

Colorectal cancer affects people of all genders, ethnicities, and races, but there are some factors that can up your chances of developing the disease, such as gender. The guidelines for colon cancer screening are the same across genders, but men are a bit more likely to deal with the condition than women, according to the American Cancer Society. Another potential piece of the puzzle? Age. ICYMI above, colon cancer most frequently occurs in people older than 50, but that doesn't mean younger folks can't get it. In fact, rates of the disease amongst younger adults are on the rise and, according to the latest findings from the American Cancer Society, 12 percent of new colorectal cancer cases diagnosed in 2020 were in people younger than 50 — a sharp increase from previous decades. (See also: Why More Young People Are Getting Colorectal Cancer)

The specific reason(s) for the increased number of cases in younger adults are still unknown. That said, "we [do] know that a number of controllable lifestyle habits are associated with an increased risk of colorectal cancer," says Arnab Ray, M.D., F.A.C.G., section head of General Gastroenterology and Hepatology and director of the GI Fellowship Program at Ochsner Medical Center. For example, eating diets low in fiber and high in red and processed meat has been linked to increased colorectal cancer. Lack of regular physical activity can also boost your chances of developing colon cancer, according to the CDC.

Researchers are also looking at certain environmental exposures, such as increased use of antibiotics, food additives, and emulsifiers (think: preservatives) — all of which Dr. Ray says he's concerned about because they "are disrupting gut microbiota in ways we are only beginning to understand." While more research is still necessary, the thinking is that taking too many antibiotics or eating lots of preservatives/additives can negatively affect the beneficial bacteria in your microbiome. And this can up your chances of intestinal inflammation — something that research and the National Institutes of Health suggest is linked to an increased risk of colon cancer.

Speaking of which, chronic health conditions such as inflammatory bowel disease — e.g. Crohn's disease, ulcerativecolitis — can boost your chances of developing the illness. And the same is true for a family history of colon cancer and polyps, according to the CDC.

And need not forget about race and ethnicity — both of which can significantly impact your odds for colon cancer, especially for communities of color. In fact, African Americans are about 20 percent more likely to get colorectal cancer and 40 percent more likely to die from it than most other groups, according to the American Cancer Society. The reasons for this are complex but stem from systematic racism, which can affect a person's ability to access adequate and culturally competent health care.

Black, Indigenous, people of color have "the most difficult time getting basic health care," says Valery Muenyi, M.D., gastroenterologist and hepatologist at Digestive Disease Consultants in Jacksonville, Florida. "Those lucky enough to have access wait several months to see a physician, who sometimes, as studies have shown, can downplay symptoms and have biases about the patient." There's also a centuries-long lack of trust between BIPOC and the health care system, she adds. And this negative relationship can also act as a barrier to preventative health care. (

People of Ashkenazi Jewish heritage (Jews of Eastern European or Russian ancestry) have a higher risk of developing colorectal cancer due to genetic mutations, according to research from John Hopkins Medicine.

Guidelines for Colon Cancer Screening

Regular screening is crucial for the successful prevention and treatment of colorectal cancer. "The earlier you catch colon cancer, the better chance you have of beating it and surviving," says Dr. Ray. "The longer you wait, the more time it has to spread and become incurable."

In general, the U.S. Preventative Services Task Force recommends that screening begins at age 45 and then continues at regular intervals (e.g. every five years) depending on your results. That being said, you may need to be tested earlier than age 45 — or more often than others — if you or a close relative have had colorectal polyps or cancer, you have IBD or other medical conditions that can potentially increase your risk of developing the disease, according to the CDC.

By now you likely know that colon cancer screening often involves a colonoscopy, a test in which a doctor inserts a long, flexible tube up your butt to check your rectum and colon for polyps. But this isn't the only exam for colon cancer prevention. There are also stool-based screenings, which require you to collect small samples of number two at home and mail them to a lab to be checked for cancer markers; flexible sigmoidoscopy, a procedure that's similar to a colonoscopy in that it uses a tube to explore your rectum but it only looks at the lower third portion of the colon (vs. the whole organ); and CT colonography or a virtual colonoscopy that uses X-rays to produce images of the entire colon.

With so many options on the "market," determining which colon cancer screening to undergo can seem overwhelming. But that's where your doctor — specifically, a GI or a general practitioner who can recommend a GI for testing — comes in. There's no one best test, according to the CDC, so talk to your practitioner about the pros and cons of each one depending on your preferences, health conditions, and resources available.

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