Colorectal cancer is the 2nd leading cause of cancer-related deaths among men and women combined in the United States, but colonoscopy screening may reduce your risk of developing cancer by up to 90%.
Most colon cancers start as precancerous growths called polyps, specifically adenomatous polyps. It may take up to 10 years for a polyp to develop into colon cancer. Regular screening with a colonoscopy, with the detection and removal of these polyps, is the most powerful weapon to prevent colon cancer.
STATISTICS
In 2014, in the United States, approximately 137,000 adults were diagnosed with colorectal cancer. There were close to 50,000 deaths from this potentially preventable disease.
The lifetime risk of developing colon cancer is 5%.
Only 50-60% of people who should get screened do get screened
Death rates from colon cancer have fallen over the last 20 years, mainly as a result of colon cancer screening.
RISK FACTORS FOR COLORECTAL CANCER
Age: The risk of developing colon cancer increases with age. This disease may occur in young adults, but more than 90% of colon cancers occur in people over the age of 50. The average age at diagnosis is 72.
Gender: There is a slightly increased incidence in men. But this is a very common cancer in women, and the screening parameters are the same.
Race: There is an increased risk of developing colorectal cancer in African Americans, and some medical societies recommend earlier screening.
Family history of colon cancer or precancerous polyps: If a person has a first degree relative (parent, sibling, child) with a history of colon cancer, that doubles their risk of developing colon cancer themselves. And this risk increases if the family member was younger than 60 when diagnosed.
Inflammatory Bowel Disease: Ulcerative colitis and Crohn’s disease increase the risk of colorectal cancer.
Personal history of colon cancer or polyps: This increases a person’s risk of developing more polyps or colon cancer in the future.
Personal or family history of rare inherited conditions: Such as Familial Adenomatous Polyposis or Hereditary Non-Polyposis Colorectal Cancer (Lynch Syndrome).
Miscellaneous: There are other factors that increase the risk of colon cancer such as obesity, physical inactivity, smoking, Type 2 Diabetes, and a diet high in red meat and low in fruits and vegetables.
HOW TO PREVENT COLON CANCER
There is no proven way to prevent colon cancer, but there are steps you can take to lower the risk.
Diet: A diet high in fruits, vegetables and whole grains and low in red meat is helpful.
Vitamins: Some studies have shown that calcium and Vitamin D may be protective
Aspirin: Some patients with hereditary polyposis syndromes may benefit from taking aspirin or anti-inflammatory medications to prevent more polyps from forming. But these medicines can cause internal bleeding, so it is not routinely recommended for patients at average risk to take them.
Lifestyle modifications: There is certainly a benefit from exercise, weight loss, smoking cessation, and limiting alcohol consumption.
Regular screening: Most colon cancers can be prevented by regular colonoscopy screening with the removal of precancerous polyps.
TESTS USED FOR COLORECTAL CANCER SCREENING
Colonoscopy: This is the gold standard for colon cancer screening. After a patient is sedated, a flexible lighted tube with a miniature camera is inserted into the colon. The physician is then able to biopsy tissue and remove precancerous polyps.
CT Scan: Also known as a virtual colonoscopy. This can detect polyps and cancer but does not allow for biopsies or polyp removal.
Barium enema: Dye in inserted into the colon and X-rays are obtained. Like a CT scan, if a polyp is seen, a colonoscopy will be needed to remove the polyp.
Fecal occult blood test: Your doctor analyzes your stool for blood which may be an indicator of colon cancer or large polyps.
Stool DNA test: Stool is analyzed for changes in DNA which may occur with colon cancer or large polyps.
COLON CANCER SCREENING RECOMMENDATIONS
Screening begins at 50 years of age for both men and women at average risk (at 45 years of age for African Americans). The findings at the initial colonoscopy determine when the next colonoscopy will be needed.
Finding Timing of next colonoscopy
Normal 10 years
Hyperplastic polyp(s) 10 years
1-2 small adenomas 5-10 years
(precancerous polyp)
3 or more adenomas, large 3 years
adenomas (greater than 10mm),
or adenomas with certain features
seen on biopsy
Colon cancer 1 year and then every 3-5 years
An initial screening colonoscopy may need to be done earlier than 50 years of age in certain individuals.
Reason Timing of first colonoscopy
Family history of colon cancer or 40 years old, or 10 years younger than
adenomas in a first degree relative youngest case in the family – then every
(parent, child, sibling) before the age 5 years
of 60, or in 2 or more first degree
relatives at any age
Family history of colon cancer or 50 years old – then every 10 years if
adenomas in a first degree relative no polyps are found
60 years of age or older, or in 2
second degree relatives
Inflammatory Bowel Disease Begin 8 years after the diagnosis if the
(Ulcerative colitis or Crohn’s entire colon is involved. Begin 12-15
disease of the colon) years after the diagnosis if only the left
colon is involved – then every 1-2
years
Personal or family history of Discuss with physician
Familial Adenomatous Polyposis
Or Lynch Syndrome
SYMPTOMS OF COLORECTAL CANCER
The above screening guidelines apply to people with no symptoms. If you develop any worrisome symptoms, you may need a colonoscopy sooner to evaluate those symptoms. By being alert to the possible symptoms of colorectal cancer, it may be possible to detect the disease early and treat it successfully. You should alert your physician about any of the following symptoms:
- change in bowel habit, including narrower or thinner stool
- diarrhea, constipation, or the feeling of incomplete rectal evacuation
- rectal bleeding
- abdominal pain or bloating
- unexplained weight loss
- fatigue
- anemia
COST OF SCREENING
Colon cancer screening is covered by Medicare. Medicare will cover a colonoscopy every 10 years for average risk patients, and every 2 years for high risk patients.
For private insurances, coverage of colon cancer screening is required by the Affordable Care Act (ACA). But this does not necessarily apply to health plans that were in place before the ACA was passed in September of 2010
HELPFUL LINKS
Utah Cancer Action Network: www.ucan.cc/Cancer%20Education/Colon%20cancer.php
American Cancer Society: www.cancer.org/cancer/colonandrectumcancer/moreinformation/colonandrectumcancerearlydetection/index
Cancer.net: www.cancer.net/cancer-types/colorectal-cance
American College of Gastroenterology: http://gi.org/guideline/colorectal-cancer-screening/
