OPEN TO THE PUBLIC
Every year, March is the month designated to colorectal cancer awareness. In the United States, colorectal cancer is the second leading cause of cancer deaths!
To put it a different way -- 1 out of every 25 people in the U.S. will be diagnosed with CRC in their lifetime – that means statistically some individuals reading this have been or will be diagnosed with colorectal cancer.
In 2020, we saw the iconic star of the Marvel Comics movie Black Panther (and numerous other movies), Chadwick Boseman, die of colon cancer at age 43. Other celebrities including Jay Monahan (husband of Katie Couric), Darryl Strawberry, Ronald Reagan, Vince Lombardi, Sharon Osbourne, Audrey Hepburn, and Ruth Bader Ginsburg have all been diagnosed with colon cancer (Source: WebMD).
Colorectal cancer can affect anyone and most are preventable – stay tuned to find out how!
What is colorectal cancer?
Colorectal cancer (CRC) is a type of cancer that develops in the colon or rectum (the last part of the colon). It is often preceded by a colon polyp that transforms into a cancer over time.
It is estimated that approximately 148,000 individuals will be diagnosed with colorectal cancer each year.
Who is more likely to develop colorectal cancer?
There are many risk factors that have been associated with colorectal cancer. The most notable risk factor is age as most individuals diagnosed with colorectal cancer are over age 50, although CRC is increasing in individuals
Can colorectal cancer be prevented?
YES! CRC is preventable in most individuals through screening. Since most colorectal cancers start as small pre-cancerous growths called polyps, there is time to detect and remove these precursor lesions before they turn into cancer. There are different ways to screen for CRC including stool-based tests and visual exams such as a colonoscopy.
Who should be screened for colorectal cancer?
The most recent recommendation by the American Cancer Society is that individuals considered at average-risk (most people) should have colorectal cancer screening starting at age 45. This is a recent change as previously CRC screening was recommended at age 50. If you have a family history of colorectal cancer, screening should be done at an earlier age.
Should I be screened if I don’t have any symptoms or family history of colorectal cancer?
YES! Most people with colon polyps or early colorectal cancer do not have any symptoms. Most colorectal cancers develop in individuals without a family history.
How can I be screened for colorectal cancer?
The decision to be screened for colorectal cancer is best discussed with your primary care physician. There are several tests that are available to consider for colorectal cancer and include:
What screening test is best for me?
The decision on which test is best for an individual depends on numerous factors including health history, family history, and patient preference (the most important factor for most!). In Virginia, only 70-80% of individuals over age 50 have had some form of colorectal cancer screening.
Ultimately, the best screening test is the one that gets done!
Here is a brief list of the advantages and disadvantages of the stool-based tests versus colonoscopy.
Does health insurance pay for colorectal cancer screening?
Most of the time YES! Colorectal cancer screening is a preventive service that many health plans cover, including Medicare and plans in the Health Insurance Marketplace. It is best to verify with your specific health insurance plan prior to choosing a screening test. NOTE: A colonoscopy to follow up on a screening test with a positive result, such as a positive stool-based test or prior colonoscopy with polyps, is considered to be a diagnostic exam and may not be covered or not covered as fully as a screening colonoscopy. Talk to your insurance provider about what your plan covers.
Where can I find out more information?
Also, here’s some relevant information on physical activity
and CRC – pertinent bullets highlighted below
Physical activity and colorectal cancer
Sports Med. 2004;34(4):239-52.
Physical activity has been shown to reduce risk of colon cancer. Some studies have shown site-specific associations while others have not. The inverse association between physical activity and colon cancer is consistent although only 7 of 13 studies that have collected both colon and rectal cancer data in the same manner report reduced risk for rectal cancer; four of these studies detected statistically significant inverse associations. The frequency, duration and intensity of activity are important components of a public health message to reduce risk of colon cancer through performance of physical activity. However, difficulties in estimating the exact amount of activity needed and frequency and intensity of activity result in only crude estimates of dose needed for a protective effect. Much of the literature suggest that more intense activity is needed to reduce colon cancer risk and that somewhere between 3.5 and 4 hours of vigorous activity per week may be needed to optimise protection. Several biological mechanisms have been proposed to explain the association between physical activity and colon cancer; many of these mechanisms also support the observation that intense activities are most protective. Biological mechanisms include: physical activity increasing gut motility; enhancing the immune system; decreasing insulin and insulin-like growth factor levels; decreasing obesity; enhancing free radical scavenger systems; and influencing prostaglandin levels. The evidence taken together provides strong support for lack of physical activity being causally related to colon cancer. It has been estimated that 12-14% of colon cancer could be attributed to lack of frequent involvement in vigorous physical activity.
Physical Activity and Risk of Colon and Rectal Cancers: The European Prospective Investigation into Cancer and Nutrition
DOI: 10.1158/1055-9965.EPI-06-0595 Published December 2006
There is convincing evidence that physical activity reduces colon cancer risk; however, the evidence for rectal cancer is unclear (1). Of the 58 studies conducted to date on colon, rectal, or colorectal cancer and physical activity (2-59), 46 studies have found a risk reduction for colon cancer among the most physically active as compared with the least active study subjects despite many different physical activity assessment methods used in these studies (3, 4, 6, 9-24, 26, 27, 31-37, 40, 42-44, 47-52, 54-61). The risk reduction observed ranged from 10% to >50%, with 27 studies (3, 6, 9, 12, 17, 19-24, 27, 31, 32, 34, 35, 37, 44, 45, 47-50, 52, 56, 58, 59) finding an average risk reduction of at least 40% for colon cancer. Very few studies have had detailed measurements of physical activity and ∼30 studies (2, 6, 8, 9, 12, 14-18, 20, 22, 24, 27, 31, 32, 34, 42, 44, 45, 51, 52, 55, 56, 58-60, 62-64) have been able to examine the risk by colon tumor subsite.
The exact biological mechanisms for the differential associations of physical activity with tumor subsites are not known. Previously hypothesized mechanisms for colon cancer include gastrointestinal transit time, immune function, prostaglandin levels, insulin-related pathways, gastrointestinal-pancreatic hormones, serum cholesterol, and bile acids (76, 77), only some of which may differ between the left or right colon. Physical activity, for example, accelerates movement of stool through the colon (78, 79), possibly providing less time for fecal carcinogens to contact colonic mucosa (80). Only the right colon is innervated by the vagus nerve, which induces peristalsis in response to physical activity. Hence, physical activity may affect motility more intensely in the right colon than in the left (81). The effect could be accentuated if foods that correlated with lower BMI (82, 83) and lower energy intake (84) are also those that traverse the colon more rapidly, such as fiber (80). Although plausible, the epidemiologic evidence for the association between gastrointestinal transit time and colon cancer risk has thus far been inconsistent (76).
In conclusion, this large prospective study conducted in a heterogeneous population of Europeans has found 20% to 25% risk reductions for colon cancer among the physically active population, which were particularly evident for right-sided colon tumors where reductions of 35% were observed. The inverse association of physical activity with right-sided colon cancer was very strong among the normal weight (BMI 25-