Why Is Colorectal Cancer So Common?
Colorectal cancer is an umbrella term used to describe a group of cancers that affect the large intestine, which includes the colon and rectum. In many cases, colorectal cancer develops after small clumps of cells (polyps) form in the lining of the colon. Polyps are common and usually harmless, but over time these initially benign cells may undergo abnormal DNA changes that cause them to gradually become cancerous, a process that generally takes place over the course of many years. The atypical cells can then amass and form tumors in the large intestine.
Currently, colorectal cancer is the third-most-common malignancy diagnosed in the United States. It is also one of the most preventable types of cancer. Although precancerous polyps do not usually produce symptoms, they can often be detected and removed during a routine screening test, such as a colonoscopy, long before they become cancerous. To capitalize on this important window of opportunity for early detection, the U.S. Preventive Services Task Force (USPSTF) recommends colorectal cancer screenings for adults aged 50 to 75. Given the growing evidence that the incidence of colorectal cancer among older adults is on the decline, this recommendation appears to be appropriate and effective.
On the other hand, the incidence of colorectal cancer among people younger than 50 is on the rise. This trend is especially troubling given the fact that the risk of colorectal cancer is known to increase with age. What’s more, today’s young people are less likely than their older counterparts to smoke or excessively consume alcoholic beverages, both of which are well-established risk factors for colorectal cancer. So, what is going on?
Know when to get screened for colon cancer
The U.S. Preventive Services Task Force (USPSTF) recommends that all adults ages 45 to 75 receive regular colorectal cancer screenings. Those at increased risk of colon cancer should receive screenings earlier than age 45. This includes individuals that:
- Have a first degree relation to someone diagnosed with colorectal cancer. For these individuals it is recommended that screening begin at an age 10 years prior to the relative's age when they were diagnosed. For example, if your father was diagnosed at age 50 with colorectal cancer, you should begin screenings at age 40.
- Have inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis
- Have been diagnosed with familial adenomatous polyposis (FAP) or Lynch syndrome
If you are at increased risk, speak to your doctor about when you should begin colon cancer screenings and which test is the right option for you.
Possible reasons for the growing prevalence among young people
Heredity is believed to play only a minor role in the development of colorectal cancer, as most cases are diagnosed in people who have neither a family history nor a known genetic predisposition. Instead, given that the increase in colorectal cancer among young adults has occurred within a relatively short time frame, researchers believe it is being driven by environmental factors, most likely a combination of lifestyle and exposure trends that have emerged over the last few decades, such as:
Dietary changes
Mounting evidence suggests that an unhealthy diet—which is high in processed meats and fats and low in fruits and vegetables—can increase the risk of early-onset colorectal cancer. As compared to previous generations, today’s young people tend to eat less fiber and more processed foods. Plus, some popular meat-heavy diet fads involve eating patterns that can promote the development of colorectal cancer, and the short-term weight loss benefits can create a dangerous distraction from the long-term health risks.
Obesity
Another common byproduct of an unhealthy diet is obesity. In young populations, the obesity rate is on the rise. The precise relationship between obesity and colorectal cancer is not yet fully understood within the general medical community, but excess body fat could fuel the development of cancer in several ways. For instance, pockets of fat that accumulate near a tumor could provide the cancerous cells with a convenient source of the energy they need to grow. Obesity can also cause hormonal changes, such as increased amounts of insulin and estrogen, both of which can accelerate the rate of cellular division. Finally, fatty tissue naturally secretes pro-inflammatory cytokines, which can further spur tumor growth.
Increased sugar intake
Glucose is the body’s most readily available source of energy. Fructose—a component of the high-fructose corn syrup found in sodas, candies and other unhealthy sweets—serves as a catalyst for glucose metabolism. Unlike glucose, however, fructose is not essential for the growth and survival of healthy cells. In excess, fructose may actually feed benign polyps, causing them to grow and proliferate more rapidly, thereby increasing the likelihood of new mutations that can lead to the development of colorectal cancer.
Awareness is key
In addition to being regularly screened for colorectal cancer, it is important for everyone—especially young people—to be aware of its symptoms, such as frequent gas, cramps, bloating, unintended weight loss, bloody stools, rectal bleeding and changes in bowel habits. Any signs that might point to colorectal cancer should not automatically be attributed to hemorrhoids or otherwise written off as normal. Instead, they should be promptly evaluated by a health care professional. For individuals who are interested in having their symptoms checked or reducing their overall risk of colorectal cancer, Moffitt Cancer Center offers both unparalleled expertise and individualized attention.
Moffitt is a high-volume cancer center, and the specialists in our renowned Gastrointestinal Oncology Program treat hundreds of patients for colorectal cancer each year. This is significant because, until recently, colorectal cancer was still relatively uncommon among young people, and therefore few oncologists have had opportunities to acquire refined experience firsthand.
Moffitt is committed to providing our patients with the answers they need, addressing their uncertainties and helping them make fully informed treatment decisions to ensure the best possible outcomes and quality of life. If you’d like to learn more about colorectal cancer or have questions about screening, contact Moffitt Cancer Center using our convenient new patient registration form or calling 1-888-663-3488 to request a consultation with a specialist.
The Right Diagnosis. Right Away.
If you've received an abnormal test result that could indicate cancer, request an appointment with our Gastrointestinal Oncology team today. Moffitt's diagnostic experts will perform the tests needed to diagnose or rule out cancer so you can know for sure.
Moffitt has the highest quality imaging technology and uses the least invasive testing procedures to give you accurate results.
If you are experiencing symptoms that might indicate colorectal cancer, please talk to your primary care physician to discuss your risks and testing options.