38. Screening for Colorectal Cancer: A Key to Prevention and Early Intervention
March is National Colon Cancer Screening Month: Have you done your colon screening yet?
Chadwick Boseman, or T'Challa, as he will forever be recognized, is the Black Panther, and he starred in the last movie, undoubtedly leaving a lasting impression on us. Just as adversaries were besieging the Black Panther king, there was a more insidious threat from within: colon cancer. Despite being diagnosed with colon cancer, Mr. Boseman continued his acting career and gained appreciation worldwide. His sudden passing from colon cancer has created a ripple effect in Hollywood and across the globe. Chadwick Boseman was 43. It is estimated that less than 10% of new colon cancers affect people younger than 50.
Colon cancer, or cancer of the large intestine, is one of the deadliest cancers and is preventable. In my quest that prevention is better than cure, this is one of the easier cancers to diagnose and treat. No one should die of Colorectal cancer due to the rapid screening techniques and new modalities. Still, Colon cancer is the third leading cause of cancer for both men and women, with an estimated fifty-two thousand dying each year. It is most common in African Americans and least common in Asian Americans. The incidence of colorectal cancer (specifically adenocarcinoma) in adults aged 40 to 49 years has increased by almost 15% from 2000-2002 to 2014-2016. Also, currently, only 75% of adults get screened.
What is Colorectal cancer?
Colorectal cancer is a form of cancer that affects the colon or large intestine. While colon cancer tends to affect older adults, it's important to remember that it can occur at any age. Colon cancer develops when colon cells experience DNA alterations that prompt them to multiply rapidly. This type of cancer usually begins as small clumps of cells known as polyps that can develop in the colon. This results in an overabundance of cells, creating a tumor capable of invading and damaging healthy tissue. Although most polyps aren't cancerous, some might turn into colon cancer over time, and the tricky part is that they often don't show any symptoms at all. That's why regular screening tests are strongly recommended. These tests help catch any polyps early on, allowing for their removal, which significantly helps in preventing colon cancer.
What are the risk factors…
Still, the factors are not known entirely. However, the list below can give a glimpse of the risk factors associated with colon cancer.
Advanced Age
African American Ethnicity high predominance
Previous Colon Cancer
Inflammatory bowel disease (Crohn's and Ulcerative colitis)
Lynch Syndrome and Familial Polyposis syndrome
Family medical history
Western Diet high in meats and low in fibre
Obesity
Tobacco use
Excessive Alcohol Consumption
Prior hx of Radiation treatment exposure What are the protective factors against colon cancer?
Studies have shown that baby aspirin and metformin are beneficial in reducing polyps, thereby decreasing the incidence of colorectal cancers.
Aspirin
Metformin
Probiotics
Physical Activity
Limiting alcohol
No Smoking Timeline of Colon Cancer Development
Colorectal cancer (CRC) typically develops over several years, progressing slowly from normal cells to cancerous tumors. As mentioned above, the process follows a well-established adenoma-carcinoma sequence. Most individuals are born and grow into early adulthood without any defects. By the ages of 20 to 40, some mutations can occur, leading to APC or Polyposis. During the ages of 30 to 50, adenomas can begin to form in the colon, and polyps typically develop slowly during this period.
Furthermore, adenomas can evolve into carcinomas over time. The most common period of development of colon polyps and progression into carcinoma is 50 to 75 years. This progression is known as the adenoma-carcinoma sequence, where benign adenomatous polyps in the colon gradually accumulate genetic mutations and transform into malignant colorectal cancer. This process usually takes up to 10 years, making early detection possible. Not all adenomas become cancerous, but factors such as polyp size (>1 cm), high-grade dysplasia, and villous histology increase the risk of malignant transformation. Since Colorectal Cancer takes 10-15 years to develop, early screening (starting at age 45 or earlier for average-risk individuals) is crucial for prevention and early detection. And maybe earlier if there is a strong family history of Colon cancer in the immediate family.
Prevention
As the diagram shows, prevention is essential and can be completely effective if the disease is caught early. Polyps take time to develop, anywhere from 10 to 20 years. Therefore, it is very important to determine the ideal age to undergo screening to determine whether polyps are present.
Prevention strategies for colorectal cancer (CRC) focus on reducing risk factors, early detection, and improving survival outcomes. Primary prevention includes avoiding smoking, excessive alcohol, and obesity while promoting physical activity, a healthy diet, and maintaining gut health. Secondary prevention involves early detection through colonoscopies, sigmoidoscopies, and stool-based tests to identify and remove precancerous polyps. Tertiary prevention emphasizes lifestyle changes post-diagnosis, such as quitting smoking, limiting alcohol, and staying active.
Screening for Colon Cancer
Colorectal cancer (CRC) screening is crucial for the early detection and prevention of the disease, significantly enhancing survival rates. It is recommended that screening begin at age 45 for individuals at average risk. Screening methods. include colonoscopy, the gold standard, and stool-based tests such as the Fecal Occult Blood Test (FOBT), the Fecal Immunochemical Test (FIT), and Cologuard, designed to find abnormal DNA in stool samples. A colonoscopy is advised every ten years, while FIT and FOBT are conducted annually, with Cologuard recommended every three years. Routine screening plays a vital role in detecting precancerous polyps that can be removed before cancer advances, thus preventing CRC. Although no testing method is perfect, early detection significantly improves patient outcomes, highlighting the importance of screening in reducing CRC-related morbidity and mortality.
In summary, as cancer rates skyrocket, especially among younger populations, it is crucial to remain vigilant. All individuals over 45 should undergo stool tests such as Cologuard or a colonoscopy. This will ensure that the colon is screened for cancer and that it can be prevented. Colon cancer is one of the diseases that can develop slowly, making it essential to take action. It's Colon Cancer Screening Month. Let's pledge to talk to your doctor and undergo colon screening. Please speak to your friends and family about screening, especially those aged 45 and above. We encourage you to discuss with your physician which screening method is good for you. Our commitment is to promote health, prevent disease, and achieve optimal health and longevity.
Talk to your doctor if you are between the ages of 45 and 75 or older about getting screened for colon cancer.
Suman Manchireddy MD FACP
Internal Medicine,
Leesburg, VA.
Email: Care@ReliantMD.com
Disclaimer: This is for purely informational and educational purposes only. Seek medical advice before starting any testing or treatment regimen. The data presented here has been extensively researched and condensed for a broader audience, and it should be viewed for educational purposes only. The blogger or blog has no affiliation with any pharmaceutical company.
Referrals:
CDC
USPS Task Force
https://www.mdpi.com/2072-6694/14/7/1732
Long-term effect of aspirin on colorectal cancer incidence and mortality: 20-year follow-up of five randomised trials
https://jamanetwork.com/journals/jama/fullarticle/2585984?resultClick=24
Thank you, Dr. Manchireddy. I understand that a blood test has been recently developed that could also assist in monitoring/diagnosis of colon cancer. Is that on the horizon as an additional tool, and if so, when might it be widely available?