Background on Colorectal Screening
American Society for Gastrointestinal Endoscopy (ASGE)
Colorectal Cancer Screening
Facts About Colorectal Cancer
Colorectal cancer (CRC), often referred to as colon cancer, develops in the colon
or the rectum (known as the large bowel or large intestine). The colon and rectum are parts of the digestive system, which is also
called the gastrointestinal (GI) tract. The digestive system processes food for energy and eliminates solid waste. CRC usually
develops slowly over many years. Most colorectal cancer begins as a noncancerous (benign) adenoma or polyp (abnormal growth) that
develops on the lining of the colon or rectum. Polyps can be removed to significantly reduce cancer risk. Colonoscopy plays an
important role in colorectal cancer prevention because precancerous polyps can be detected and removed during the same exam when they
CRC is the third-leading cause of death from cancer in the
United States for men and women. It is the third most commonly diagnosed cancer in the United States (excluding skin cancers).
More than 140,000 people in the United States are diagnosed
with colorectal cancer each year, and over 50,000 die because of it annually.
The majority of CRC can be prevented with proper screening,
early detection and removal of adenomatous polyps. Screening helps prevent CRC by finding precancerous polyps so they can be removed
before they turn into cancer.
Only about 50 percent of adults who should have colonoscopies
comply with recommended guidelines. More than 60 percent of Americans aged 50 or older, approximately 42 million people, have not
utilized any screening method for CRC.
Exercise and eating healthy foods such as vegetables and
fruits can help decrease the risk of colorectal cancer.
As of November 2010, there is no federal law requiring all
insurers to cover the cost of preventative CRC screenings. However, the recent enactment of the Affordable Care Act requires coverage
of CRC screenings for certain populations depending on individual’s insurance plan. So far only 30 states have passed laws requiring
coverage for screening of CRC-a cancer causing 50,000 deaths per year. In contrast, 50 states have passed legislation requiring
coverage of screening for breast cancer-a cancer causing 40,000 deaths per year. Additional efforts to improve colorectal cancer
screening are needed. Medicare covers colonoscopy once every ten years for those 65 and over at average risk.
The incidence of CRC and the death rate from the disease has
dropped for the past 15 years. Scientists believe that the decrease is probably because polyps are being found and removed by
colonoscopy before becoming cancer. Also, CRC is being found earlier when it is easier to cure, and treatments for cancer once it has
occurred have improved. There are approximately one million CRC survivors in the United States, and that number is growing.
The five-year survival rate for people with CRC discovered
early is greater than 90 percent. But only 39 percent of CRCs are found at that early stage. Five-year survival rapidly declines when
the cancer has spread to nearby organs or lymph nodes.
Individuals who have a family member (parent, brother or
sister, or child) with colorectal cancer or polyps are at increased risk for developing the disease themselves and may need to undergo
more aggressive screening starting at a younger age. Individuals who have more than one family member with colorectal cancer or with
other types of cancers may be at even higher risk.
Symptoms of CRC
Certain symptoms might indicate this cancer:
blood in the stool
narrower than normal stools
unexplained abdominal pain
unexplained change in bowel habits
If you experience any of these symptoms, talk with your physician. CRC can
also occur without symptoms, family history, or any predisposing conditions such as inflammatory bowel disease. When a patient is
being evaluated for symptoms, this is NOT considered screening but diagnostic evaluation. The term screening is reserved for healthy,
SCREENING RECOMMENDATIONS FOR
THOSE AT AVERAGE RISK:
Beginning at age 50, both men and women at average risk for developing CRC should
have a colonoscopy every 10 years. The risk of developing CRC increases with age, with more than 90 percent of cases occurring in
persons aged 50 or older.
Men and women should begin screening earlier and more often if they have any
of the following CRC risk factors: a family history of CRC or polyps, a known family history of inherited CRC syndromes, a personal
history of CRC, or a personal history of chronic inflammatory bowel disease (ulcerative colitis or Crohn's Disease).
People with risk factors for CRC or family history of CRC should talk with a
gastroenterologist about screening at an earlier age and find out how often they need to be screened. Read ASGE’s colorectal cancer
There are several screening methods which have different abilities to detect
or prevent CRC: stool blood test known as Fecal Occult Blood Test (FOBT) or Fecal Immunochemical Test (FIT), flexible sigmoidoscopy,
colonoscopy, CT colonography, barium enema with air contrast, and stool DNA testing. Tests which mainly detect cancer include FOBT and
stool DNA. Tests which mainly detect polyps or cancer include colonoscopy, flexible sigmoidoscopy, CT colonography and barium enema.
Colonoscopy is considered the gold standard of colorectal cancer screening methods for its ability to view the entire colon and both
detect and remove polyps during the same procedure.
Patients should speak with their physician about the screening method that is
best for them. To learn more about CRC prevention and available screening options, log on to ASGE’s colorectal cancer awareness Web
DIET AND LIFESTYLE:
There are no foods that directly cause colorectal cancer. However, studies of
different populations have identified associations that may affect your risk of developing colorectal cancer. Smoking clearly
increases the risk of colorectal cancer and other cancers. Studies have shown a slight increased risk of developing colorectal cancer
among individuals with higher red meat or non-dairy (meat-associated) fat intake. Studies have also shown that getting an adequate
amount of calcium and vitamin D in the diet or from supplements can reduce the risk of polyps and cancer. Use of aspirin and NSAIDs
(such as celecoxib and sulindac) has been proven to decrease the risk of colorectal polyps. There may be a decreased risk of
colorectal cancer in patients taking aspirin. However, the use of these agents is reserved for individuals at high risk for colorectal
polyps and cancer.
Ongoing studies evaluating the role of vitamins and other natural products
are underway to examine their role in colorectal cancer prevention. Few studies, though, have been able to show that modifying
lifestyle reduces the risk of colorectal polyps or cancer. Nonetheless, lifestyle modifications such as reducing dietary fat,
increasing fruits and vegetables, ensuring adequate vitamin and micro-nutrient intake, and exercise, may improve general health.
Regardless of your dietary and lifestyle habits, screening for colorectal
polyps is the key in preventing colorectal cancer.
WHAT AFRICAN-AMERICANS SHOULD KNOW
Although all men and women are at risk for CRC, some people are at higher risk for
the disease because of age, lifestyle or personal and family medical history. According to studies, African-Americans are at a higher
risk for the disease than other populations. Starting at age 50, everyone should begin routine screening tests. Research shows that
African-Americans are being diagnosed at a younger average age than other people. Therefore, some experts suggest that
African-Americans should begin their screening at age 45.
The incidence of CRC is higher among African-Americans than
any other population group in the United States.
Death rates from CRC are higher among African-Americans than
any other population group in the United States.
There is evidence that African-Americans are less likely than
Caucasians to get screening tests for CRC.
African-Americans are less likely than Caucasians to have
colorectal polyps detected at a time when they can easily be removed.
African-Americans are more likely to be diagnosed with CRC in
advanced stages when there are fewer treatment options available. They are less likely to live five or more years after being
diagnosed with CRC than other populations.
There may be genetic factors that contribute to the higher
incidence of CRC among some African-Americans.
African-American women have the same chance of getting CRC as
men, and are more likely to die of CRC than are women of any other ethnic or racial group.
African-American patients are more likely to have polyps
deeper in the colon (on the right side of the colon).
WHAT HISPANICS SHOULD KNOW ABOUT CRC:
Hispanic Americans are less likely to get screened for the
disease than either Caucasians or African-Americans.
For more information about colorectal cancer prevention or to find a
qualified doctor in your area, visit ASGE's colorectal cancer awareness Web site at
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