Sponsored by: Main Line Health System
Thousands of cancer cases yearly could be prevented by using a test that already exists, but would you believe that more than 40 percent of at-risk people haven’t received it? Dr. John H. Marks discusses how to prevent colorectal cancer, and why some are reluctant to be tested.
Marks is Chief of Colorectal Surgery for Lankenau Medical Center, part of the Main Line Health System near Philadelphia, Pennsylvania. He directs a colorectal surgical research team and a fellowship in Minimally Invasive Colorectal Surgery and Advanced Rectal Cancer Management, one of only four in the United States.
It’s estimated that 137,000 men and women will be diagnosed with colorectal cancer (CRC) this year, while another 50,000 will die from it. In fact, CRC is the second leading cause of cancer deaths of U.S. men and women. The disease claimed more than 694,000 lives worldwide in 2012, according to the World Health Organization.
But did you know that with proper screening, colorectal cancer can be completely prevented?
That’s right. Marks said that’s because colorectal cancer is one of the most preventable cancers and a simple, but impactful, test can keep you CRC-free, and even save your life.
In honor of National Colorectal Cancer Awareness Month, we sat down in March with Dr. Marks to talk about this disease.
For the past decade there has been a sustained effort to increase public awareness around the benefits of colorectal screening and increased access to treatment.
And yet only 59 percent of people aged 50 or older, for whom screening is recommended, reported having been screened consistent with the current guidelines, according to the National Health Interview Survey.
From your experience, what factors keep so many people from participating in screening?
The reality is, for most people, talking about their colon is an embarrassing topic and I think there is a certain amount of dread about prepping for a colonoscopy. The real take-away here is that taking early action can prevent most colon and rectal cancers from ever happening.
When it comes to screening, is colonoscopy still considered the gold standard test or are less invasive screening tests just as effective?
Colonoscopy is still the gold standard screening test because it has the added advantage of being diagnostic and therapeutic with a single exam. If a polyp is discovered during the exam, it can be immediately removed, preventing it from becoming cancerous. As with any procedure, there is always a small amount of inherent risk, but this is far outweighed by the potential benefits.
There are other CRC tests available to patients that are considered somewhat less invasive, and while they can also be less reliable, they’re great to just get your toe in the water. Those found to have a polyp or suspected cancer during the other types of screening examination are then referred for colonoscopy.
With that said, choosing one of these other recommended screenings is better than no screening at all. Screening is such a powerful tool in combating CRC.
If a precancerous polyp is found during the screening exam, the patient is cured before they even develop a cancer. If cancer is found at an early stage during the screening exam, while small and before it has spread, it is more easily treated. It’s estimated 9 out of 10 people whose colon cancer is discovered early will be still alive five years later.
When should CRC screening start?
For most asymptomatic people, it's recommended to start between the ages of 45 and 50. However, some people should start screening much earlier.
For instance, people who have a strong family history of colorectal cancer should begin screening as early as their mid-20s, pending conversations with their doctor. People who have been diagnosed with other cancer types, including breast, ovarian, testicular or lymphoma, or those who have a personal history of inflammatory bowel disease are at higher risk for CRC and may be advised by their doctor to begin screening earlier.
The same is true for African-American men and women and people of Ashkenazi-Jewish descent. It is recommended that they begin screening at age 45 because those racial groups get CRC at a disproportionally higher rate than other groups.
On the other end of the spectrum, general colonoscopy guidelines are not recommended for asymptomatic people older than 75. However, with the population living longer and enjoying good health into their 80s and even 90s, patients should discuss individual screening recommendations with their physician.
What are the symptoms of CRC?
Early colorectal cancers may not cause any symptoms. This is why screening is so important. It should be noted that the screening guidelines are for asymptomatic patients. Those experiencing symptoms should undergo colonoscopy regardless of age.
Generally speaking, a change in bowel habits, such as diarrhea, constipation or narrowing of the stool, which lasts for more than a few days, is worth discussing with your doctor. Rectal bleeding, blood in the stool which may cause the stool to look dark, cramping or abdominal pain, unexplained weakness and fatigue, or unintended weight loss are also common symptoms.
Anyone who is experiencing any of these symptoms or a combination of symptoms should see their doctor as soon as possible.
What should people know about maintaining good colon health?
Maintaining good colon health is the same as maintaining good health in general.
Certain lifestyle factors — smoking, alcohol use, eating diets rich in red meat or processed meat and not eating enough fruits, vegetables and whole grains, having a Body Mass Index (BMI) over 25 (the generally accepted level for obesity), and not getting enough exercise — can raise a person’s risk of getting colorectal cancer.
These lifestyle factors are pretty consistent with other diseases too, such as heart disease and type 2 diabetes.
Hands down, the most powerful thing a person can do to prevent colon cancer is to get screened. But having more conversations about CRC will help too. We need to alleviate the embarrassment factor for people so we can prevent this disease and save lives.
Interview. Dr. John H. Marks. 3 Mar. 2015
World Health Organization. Cancer Fact Sheet.
Colorectal Cancer Facts. Fight Colorectal Cancer. Accessed online at:
Reviewed March 6, 2015
by Michele Blacksberg RN
Edited by Jody Smith