Duncan Hamilton, DO, is a general surgeon specializing in numerous areas of surgery, including colonoscopies and upper endoscopies.
Dr. Hamilton is committed to providing excellent surgical care to patients in the region.
Both Hamilton and trusted resources offer the following recommendations to guide your care.
5 Things to Know About Colorectal Cancer
Colorectal Cancer (CRC), including cancers of the colon and rectum, is one of the most common cancers impacting both men and women. So common that the World Health Organization recognizes the disease as the third most common cancer and the second leading cause of cancer deaths worldwide, only after lung cancer. The estimated risk for developing CRC in your lifetime is 1 in 24 for men and 1 in 26 for women. While the risk of developing CRC increases with age, several risk factors, including diet, tobacco use, and family history, could contribute to developing the disease before the age of 50.
CRC is on the rise for younger adults, including those who are generally healthy. The American Cancer Society (ACS) shares that 1 in 5 people diagnosed with CRC are now under 55, and the number of younger people being diagnosed has been on the rise since the 1990s. Keeping this in mind, it’s never too early to be informed about CRC.
Continue reading to learn more about the symptoms, risk factors, screening options, and prevention of CRC.
1. What is Colorectal Cancer?
Colorectal Cancer occurs as a growth in the colon or rectum, both of which make up the large intestine, part of the gastrointestinal system. These growths are known as polyps. Polyps can be quite common, and many are benign and noncancerous.
However, some of these polyps can become cancerous over time, particularly villous adenomas, which are the least common but also the most likely to develop into cancer.
The cancer begins in the innermost layer of the colon wall and can grow into blood vessels and lymph nodes. The most common type of CRC is adenocarcinoma, characterized as a glandular cell cancer.
2. Risk Factors + Prevention
While anyone can develop CRC, several risk factors can heighten your risk of developing the disease at some point in your life.
Age
Your risk increases as you age; However, CRC is on the rise for those under 50, and the exact reason is still unknown.
Personal or Family History
If you have a personal history of inflammatory bowel disease (including Crohn’s Disease and Ulcerative Colitis), colorectal polyps or CRC, or have previously received radiation to the abdomen or pelvis area, your screening for CRC may need to be earlier and/or more frequent. Additionally, those who have undergone a cholecystectomy (gallbladder removal) have been found to have an increased risk, according to the American Cancer Society.
As far as a family history, if you have a first-degree relative (parent, sibling, or child) who has had CRC, especially if they were diagnosed before the age of 50, or if you had more than one first-degree relative be diagnosed, your risk of developing CRC is heightened. So much so that 1 in 3 diagnosed with CRC has a family history of the disease.
Being informed about your family’s history of CRC or adenomas is important. You should let your family medicine provider know about any close relatives with these conditions, as they can determine personalized screening guidelines.
Racial or Ethnic Background and Sex at Birth
American Indian, Alaska Native, Ashkenazi Jews, and African American men and women are at the highest risk of developing CRC. Additionally, men of any ethnic or racial background have a higher fatality risk from CRC than women. Individuals should be aware of the genetic risks for CRC and monitor the symptoms they experience, if any.
Smoking and Alcohol Use
As is the case in many other cancers and health conditions, smoking and alcohol use lead to a heightened risk of developing CRC at some point in your life. In a study detailed in the American Journal of Epidemiology, those who smoke were identified as having a 39% higher risk for men and a 20% higher risk for women for developing CRC. Smoking is a commonly known contributor to lung cancer, but its negative impacts stretch across a multitude of conditions—CRC included.
For alcohol consumption, the American Cancer Society details an elevated risk for even light to moderate intake. If you do not already drink, do not start. However, the guidelines indicate women should have no more than one drink per day and men no more than two drinks per day.
In a study detailed in the Journal of Clinical Oncology studying the impact of alcohol and CRC diagnosis before the age of 50, 26% of men and 47% of women were at an increased risk for developing early onset CRC (before age 50) for moderate or heavy drinkers. Therefore, limiting or eliminating alcohol from your diet may lower your risk.
Obesity & Diet
Nearly 40% of adults in the United States are obese. The American Cancer Society indicates that the risk of developing CRC for those with excess body weight or obesity is heightened compared to those at a healthy weight. The risk for developing CRC or another cancer is influenced by excess weight, increasing inflammation in the body, impacting hormones, and the speed at which cells can spread. The full impact of obesity on cancer risk is still being researched; however, it is understood through current research that the risk is increased.
When it comes to the standard American diet, many of us heavily consume processed foods and red meats, such as hot dogs, beef, and pork, which raise our CRC risk. A meta-analysis study citing tens of studies, addressing the links between red and/or processed meats and CRC, found a 20-30% increased risk.
When these meats are cooked at a high temperature, such as grilling or frying, heterocyclic amines (HCA) and polycyclic hydrocarbons (PAH) are created. Research from the National Cancer Institute suggests that HCAs and PAHs can alter DNA and possibly increase your risk for cancer.
Red meats do contain protein, iron, and a few other nutrients, but the best foods to eat to nourish your body to receive these same nutrients include dark leafy greens, fish or seafood, and poultry. Consuming a healthy, balanced diet including protein, fruits, vegetables, and whole grains ensures the body receives what it needs to thrive.
While the occasional hamburger on the 4th of July or a hot dog at a baseball game will not shoot your risk of developing CRC through the roof overnight, long-term, excessive consumption of red and processed meats increases your risk.
Type 2 Diabetes
For those with Type 2 Diabetes, individuals are at an increased risk of developing CRC than those who don’t. This increased risk, as detailed by Harvard Medical School, is 47% higher compared to those without the condition. Comorbidities between diabetes and CRC were first discovered in the late 1990s, and since then, researchers have been committed to understanding the connection. The risk only increases for those with both Type 2 diabetes and smoke. Managing your A1C, following a healthy diet, and receiving regular screenings are crucial.
While some of these risk factors are genetic and unchangeable, many others can be reduced or eliminated through lifestyle changes.
3. Symptoms
In the early stages of colorectal cancer, the individual may not have any symptoms, but as the condition progresses, several troubling symptoms can occur. Being informed about the symptoms of colorectal cancer can help you be aware of what to look for.
Some of the symptoms include a change in normal bowel habits (including size, shape, and frequency), diarrhea or constipation that does not go away, discomfort or pain during bowel movements, abdominal pain or cramping, a change in appetite, blood in the stool, weight loss without trying, and more. Experiencing these symptoms does not necessarily mean you have colorectal cancer, but if you experience these changes for more than two weeks, schedule an appointment with your family medicine provider as soon as possible.
As is the case in some other cancers, those with colorectal cancer may experience no initial symptoms; that’s why regular screenings are crucial to the early detection of the disease.
4. Screenings
The American Cancer Society recommends that screenings for those at average risk of developing colorectal cancer begin at age 45. This screening age has fairly recently lowered from 50, as diagnoses are trending younger.
Screenings should then continue through age 75, but from 76 to 85, screenings are based on personal preference, life expectancy, and overall health.
For those with a family or personal history of colorectal cancer or a personal history of inflammatory bowel disease, these recommendations may be different, and it’s important to discuss your risk and screening options with your family medicine provider.
“Early detection is key to diagnosing, monitoring, and treating colorectal cancer, said Duncan Hamilton, DO, a general surgeon at Decatur County Memorial Hospital. “Routine screenings like colonoscopies allow us to discover polyps and evaluate for signs of colorectal cancer or other bowel concerns.”
Screening options for colorectal cancer are varied, as are the screening frequencies. For a standard colonoscopy, screenings are recommended every 10 years for those at average risk. On the other hand, stool-based tests, such as Cologuard, are recommended every 3 years following a negative result.
Weighing the pros and cons of both screening types, it’s important to consider the differences between the two screening types. Colonoscopies are traditionally considered the “gold standard” for colorectal cancer detection. The doctor can examine and remove most polyps. For those with the higher risk factors detailed above, a colonoscopy is the standard.
However, for those at average risk, Cologuard may be a more convenient or comfortable option, as the prep required for a standard colonoscopy is not necessary in these tests.
Speak with your family medicine provider to determine which screening type is best for you.
5. Scheduling a Screening
Call 812-222-DOCS to schedule an appointment with your family medicine provider.
Decatur County Memorial Hospital is proud to have a team of highly qualified general surgeons who can complete colonoscopies on-site in our surgery unit.
The information provided in this health insights article is intended for general informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your qualified health provider with any questions you may have regarding a medical condition. Don’t disregard professional medical advice or delay in seeking it because of something you have read on this article.
Additional References:
- American Cancer Society. (n.d.-a). Colorectal cancer guideline: How often to have screening tests. American Cancer Society. https://www.cancer.org/cancer/types/colon-rectal-cancer/detection-diagnosis-staging/acs-recommendations.html
- American Cancer Society. (n.d.). Colorectal cancer risk factors: Hereditary colorectal risk factors. Colorectal Cancer Risk Factors. https://www.cancer.org/cancer/types/colon-rectal-cancer/causes-risks-prevention/risk-factors.html
- American Cancer Society. (n.d.). Excess body weight and cancer risk. Excess Body Weight and Cancer Risk. https://www.cancer.org/cancer/risk-prevention/diet-physical-activity/body-weight-and-cancer-risk.html
- American Cancer Society. (n.d.-b). Colorectal cancer prevention: How to prevent colorectal cancer. American Cancer Society. https://www.cancer.org/cancer/types/colon-rectal-cancer/causes-risks-prevention/prevention.html
- American Cancer Society. (n.d.-b). Colorectal cancer screening tests: Sigmoidoscopy & Colonoscopy. American Cancer Society. https://www.cancer.org/cancer/types/colon-rectal-cancer/detection-diagnosis-staging/screening-tests-used.html
- Aykan N. F. (2015). Red Meat and Colorectal Cancer. Oncology reviews, 9(1), 288. https://doi.org/10.4081/oncol.2015.288
- Centers for Disease Control and Prevention. (n.d.-a). Screening for colorectal cancer. Centers for Disease Control and Prevention. https://www.cdc.gov/colorectal-cancer/screening/index.html
- City of Hope. (n.d.). Cologuard vs. colonoscopy: How to decide and test accuracy. https://www.cancercenter.com/community/blog/2024/01/cologuard-vs-colonoscopy
- Edwards, E. (2023, May 9). The link between diabetes and colorectal cancer: Exploring the evidence. Colon Cancer Foundation. https://coloncancerfoundation.org/the-link-between-diabetes-and-colorectal-cancer-exploring-the-evidence/
- Godman, H. (2024, March 1). Colon cancer risks higher in people with diabetes. Harvard Health. https://www.health.harvard.edu/diseases-and-conditions/colon-cancer-risks-higher-in-people-with-diabetes
- Gram, I. T., Park, S. Y., Wilkens, L. R., Haiman, C. A., & Le Marchand, L. (2020). Smoking- Related Risks of Colorectal Cancer by Anatomical Subsite and Sex. American Journal of Epidemiology, 189(6), 543–553. https://doi.org/10.1093/aje/kwaa005
- Jin, E. H., Han, K., Min Shin, C., Ho Lee, D., Joo Kang, S., Hyun Lim, J., & Jin Choi, Y. (2023, June 14). Sex and Tumor-Site Differences in the Association of Alcohol Intake with the Risk of Early-Onset Colorectal Cancer. ASCO Publications. https://ascopubs.org/doi/full/10.1200/JCO.22.01895
- Lynch, P. (2023, August 1). Alcohol: Destroying your liver and colon, increasing your risk of early CRC. Colon Cancer Foundation. https://coloncancerfoundation.org/alcohol-destroying-your-liver-and-colon-increasing-your-risk-of-early-crc/
- Menon G, Cagir B. Colon Cancer. [Updated 2025 Feb 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470380/
- Staff, C. (2025, September 23). Colorectal cancer rates are skyrocketing in young adults-is your lifestyle putting you at risk? . Cancer Research Institute. https://www.cancerresearch.org/blog/colorectal-cancer-awareness-month#_ftn2
- Thomme, G. V. (2024, April 8). Why is red meat bad for you?. MD Anderson Cancer Center. https://www.mdanderson.org/cancerwise/is-red-meat-bad-for-you.h00-159696756.html
- What is colorectal cancer?: How does colorectal cancer start?. How Does Colorectal Cancer Start? | American Cancer Society. (n.d.). https://www.cancer.org/cancer/types/colon-rectal-cancer/about/what-is-colorectal-cancer.html