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5 Things Doctors Want You to Know About Colon Cancer

Learn the important facts about colon cancer and symptoms to watch out for. 
FACT CHECKED BY Emilia Paluszek

Although there's been a lot of breakthroughs in cancer prevention and treatments, it's still the second leading cause of death in the United States and colon cancer is the fourth most common type for men and women, according to the Centers for Disease Control and Prevention. While a small percentage of cases are due to non-modifiable factors such as family history, the majority is thought to stem from lifestyle choices like smoking, lack of exercise and poor diet, the UTSouthwestern Medical Center says. "Colon cancer diagnoses (around 70 percent) are considered random or sporadic and non-hereditary, without a known etiology.

Risk factors for sporadic colon cancer include:

–Inflammatory bowel disease, ulcerative colitis, Crohn's disease

–Diets high in fat and/or low in fiber

–Smoking/tobacco use

–Physical inactivity and/or obesity

–Type 2 diabetes"

It's not uncommon to have colon cancer and not realize it because signs often don't appear until later stages. And with colon cancer on the rise in people under 50, colon cancer is an even more serious health issue. However, there is good news. "About 90 percent of colorectal cancers and deaths are thought to be preventable. In addition to regular colorectal cancer screenings, exercise and maintaining a healthy weight can reduce your risk of colorectal cancer," The University of California San Francisco states. 


What to Know About Colon Cancer

prostate cancer

Misagh Karimi, M.D., medical oncologist specializing in gastrointestinal cancers at City of Hope Orange County Lennar Foundation Cancer Center in Irvine, California, and director of clinical operations at City of Hope Newport Beach Fashion Island tells us, "Colon cancer is the third most commonly diagnosed cancer in the U.S. Most colorectal cancers start as growths called polyps in the smooth inner lining of the colon or rectum. More than most other cancers, colon cancer is affected by things you can control, like what you eat and how much you exercise. Eating a diet that includes plenty of vegetables, fruits and whole grains — and that is low in animal fat — has been linked with a lower risk of colon cancer. Other lifestyle changes like quitting smoking, drinking less and exercising regularly may help lower your risk as well. 

In addition, the majority of people with colorectal cancer, about 70 percent, do not have inherited conditions that signal higher risk. This means that, for most people, making healthy lifestyle choices and getting screened as their physician recommends are the most important things they can do to lower their risk of colorectal cancer. It's very important to undergo recommended screenings and it's not too early to think about them if you're in your 40s. The American Cancer Society recommends that people of average risk of colorectal cancer start regular screening at age 45. Follow-up colonoscopies should be done every 1-3 years, depending on the individual's risk and findings from the first test. Simply put, risk reduction and early detection are the keys to better outcomes."


Colon Cancer is Now Common in People Under 50

talk to doctor

Dr. Karimi says, "In recent years, we're seeing a significant shift in colon cancer trends. While cases are decreasing among individuals 65 and older, they've been increasing among the younger population in adults 50 years of age and younger. In fact, one in five colorectal cancer diagnoses are in people ages 20 to 54. Studies show that for people born in the 1990s, the risk of colorectal cancer is double that of people born in the 1950s and the death rate is also higher. This is likely due to diet and lack of exercise.

We know that exercise is a huge component in an individual's overall health, and we are seeing that more time exercising and less time sitting does impact the risk of colorectal cancer. Half of the patients diagnosed who are in the younger demographic are overweight. As a medical oncologist who sees patients every day, I advise my patients to eat nutritious foods and get daily exercise — even if it's just 10 minutes a day. Small changes make a big difference. The best way to stop cancer is to prevent it in the first place, and the sooner you make healthy choices, the greater the potential benefits."


Colon Cancer Misconceptions

Woman holding model of human intestines in front of body.

According to Dr. Karimi, "Many people think this is a disease that afflicts older men. However, not only does colorectal cancer affect younger people, it is also only slightly more common in men than women. Another misconception I hear is that people don't think they need to be screened because they don't have symptoms, but signs of colorectal cancer tend to appear when the cancer is in its later stages. 

Patients with colon cancer may not have any symptoms at all, or their symptoms may be the same as those of other gastrointestinal issues. Without symptoms, polyps containing cancer cells can remain in the colon wall for not just months, but for years. Once severe symptoms arise, the cancer has usually progressed to a more advanced stage. This is one of many reasons why people should know their family medical history and tell their physician if something feels wrong. If the symptoms might be caused by colon cancer, there are screening tests that can be done to find the cause."


Signs of Colon Cancer

Gastrologist. Doctor's office. Doctor gastroenterologist with probe to perform gastroscopy and colonoscopy

Dr. Karimi emphasizes, "Warning signs of colon cancer that people should never ignore and notify their doctor of include: 

–A change in bowel habits that lasts for an extended length of time (more than a few days), 

–Bleeding of the rectum

–Blood in the stool

–Abdominal pain


–Weakness or fatigue


–Unintended weight loss

–Nausea and vomiting

If you have been diagnosed with colon cancer, consult with a physician who specializes in this disease before starting treatment. A colorectal cancer specialist with knowledge of the latest advances in research and treatment can help you fully understand your options so you can make the best possible decisions."


Colon Cancer Can Spread Slowly and Screenings are Lifesaving

Doctor gastroenterologist with probe to perform gastroscopy and colonoscopy

Dr. Karimi explains, "We know that polyps containing cancer cells can stay lodged in the colon wall for months, even years, without causing bleeding, pain or other symptoms. Screening increases the chances of catching colon cancer at an early stage, before it has spread and when it is more likely to be cured. At City of Hope Orange County, we are committed to increasing the number of lifesaving screenings for colon cancer and we offer state-of-the-art diagnostic tools, including colonoscopies, stool DNA testing and genetic screening.

Thanks to screening and new therapies, the prognosis is very good for colon cancer when it is caught early. Colorectal cancer is one of the most curable cancers, yet research shows that tens of millions of people are skipping out on lifesaving screening due to fear of bowel preparation, fear of the test and fear of the results. Don't let anxiety about a colonoscopy keep you from getting screened – it is a painless exam done under sedation and usually takes less than 30 minutes. The research has proven that colon cancer screening saves lives."

Heather Newgen
Heather Newgen has two decades of experience reporting and writing about health, fitness, entertainment and travel. Heather currently freelances for several publications. Read more about Heather
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