Colorectal cancer (CRC) — cancer that starts in the colon or the
rectum — is the fourth most common cancer diagnosed in men and women
in the United States, and the second leading cause of cancer death.
“Despite its high incidence, if found early, CRC is one of the most
preventable, treatable and beatable forms of cancer,” BCH gastroenterologist
Dennis Ahnen, MD, AGAF, FACG, said during a free health lecture held in Boulder earlier this month.
CRC often begins with benign or non-cancerous polyps, which are flat or
knob-like growths on the lining of the large intestine. While some polyps
remain benign, others develop into cancer over time.
“It can take 10 to 15 years for precancerous polyps to develop into
CRC. Through screening, we can find these polyps and remove them before
they have a chance to turn into a potentially lethal cancer,” Dr.
Ahnen said. “Screening can also find the cancer in its early stages,
when it’s the most curable.”
The Best Screening is the One That Gets Done
According to Dr. Ahnen, for most men and women, screening for CRC should
begin at age 45 or 50 and continue until age 75. If you have a first degree
relative — parent, brother, sister or children — who has had
colon cancer, talk to your provider about getting screened at age 40 or
10 years before the age that your family member was diagnosed with colon
cancer, whichever is earlier.
There is more than one way to get screened for colon cancer, from at-home
stool blood tests, stool blood plus DNA tests, flexible sigmoidoscopy,
CT colonography and colonoscopy screening.
“The advantage of a colonoscopy screening is that it can both find
and remove polyps—all in a single test. Its prep can be difficult,
but the preps are getting better,” Dr. Ahnen said.
Talk to your doctor about the pros and cons of the different types of screening.
Each has advantages and disadvantages.
“However, the best test is the one that gets done well," Dr.
Pay Attention to Your Risk Factors
Dr. Ahnen explained that both men and women have the same lifetime risk
of colon cancer, which is about 5 percent. Although no one knows the exact
cause of the cancer, you should pay attention to these identifiable risk factors:
Age over 50: Colon cancer becomes more common as people age. In fact, more than 90
percent of those with colon cancer are diagnosed after age 50.
Diet and lifestyle: Diets high in red or processed meat can increase your risk, as well as
diets low in fruits, vegetables and fiber. Physical inactivity, obesity,
cigarette smoking and heavy alcohol use have also been linked to higher
risk of colon cancer.
Family history of polyps: If you or a family member has a history of polyps, it may put you at
a higher risk.
Family history of colon cancer: When a first degree relative of yours has had colon cancer, you are more
likely to develop this disease.
Tell Your Relatives: Family History Can Elevate Risk
Dr. Ahnen stated that roughly 10 percent of the population has a family
history of colon cancer. This group has a higher than average risk for
developing the disease.
He explained further: "Your colon cancer risk is related to the number
of close relatives you have with colon cancer and whether any of them
had colon cancer at a young age (less than 50 years). If you have a first
degree relative (FDR), meaning a parent, sibling or child with colon cancer,
your risk is about two-fold higher than the general population. If you
have one FDR with colon cancer under the age of 50, or two FDRs with the
cancer regardless of age, your risk is increased by about three-to-four
fold. Finally, if you have more than two first degree relatives with colon
cancer, your risk goes up eight fold compared to the general population.”
Dr. Ahnen concluded with a call to action, saying, "Reach out! If
you know you have relatives with colon cancer, tell your medical provider
about your cancer family history and tell your other relatives to get
screened and get informed!"
Dennis Ahnen, MD, FACG, has more than 40 years experience in successfully screening for and treating
gastrointestinal diseases. Appointments are available by calling Gastroenterology
of the Rockies at 303-604-5000.
Click here to view PowerPoint slides from Dr. Ahnen’s lecture on "Averting
the Preventable Killer - Colon Cancer."