Updates in Colorectal Cancer Screening and Early Detection

Introduction

Colorectal cancer originates in the colon or rectum and is commonly referred to as either colon cancer or rectal cancer, depending on its point of origin. These two types of cancer are often grouped due to their shared characteristics. The majority of colorectal cancers start as growths in the inner lining of the colon or rectum, known as polyps. Over time, some polyps may evolve into cancer, though not all polyps are cancerous. Colorectal cancer is categorized based on the type of polyp present. Regular screening for colorectal cancer is crucial for early detection and effective management, ultimately preventing its progression and spread.

What Is the Importance of Early Detection of Colorectal Cancer?

Early detection of colorectal cancer is important for providing patient care. It improves treatment success, enhances survival rates, minimizes treatment complexity, reduces costs, preserves organ function, and contributes to an overall quality of life. Also, early intervention prevents disease progression and supports the effectiveness of screening programs over the long term.

What Are the Current Screening Guidelines for Colorectal Cancer?

The current screening guidelines for colorectal cancer recommend various procedures to detect and prevent the disease, particularly in its early stages when symptoms are minimal.

• Colonoscopy: It is advised to start at the age of 50 and should be repeated every ten years, though the frequency may vary based on individual risk factors and overall health.

• Flexible Sigmoidoscopy: A procedure similar to a colonoscopy but examining only the lower part of the colon, is recommended every five years and is often combined with stool testing.

• Stool-Based Test: It includes the fecal immunochemical test (FIT) or high-sensitivity guaiac-based fecal occult blood test (gFOBT), which is conducted annually and is an alternative to colonoscopy or sigmoidoscopy.

• Genetic Testing: Suggested for individuals with a family history of colorectal cancer or certain genetic conditions, with screening methods tailored based on genetic risk factors.

• Risk Assessment Evaluation: It evaluates factors such as family history, personal history of colorectal polyps or cancer, and certain hereditary conditions that could lead to colorectal cancer.

What Are the Advancements in Screening Technologies for Colorectal Cancer?

Research and studies have been dedicated to finding ways to prevent, detect, and treat colorectal cancer at its earliest stages. Screening plays an important role in reducing the risk of colorectal cancer by identifying precancerous lesions or polyps before they transform into cancer. The new advancements in screening tests include:

Virtual Colonoscopy (CT Colonography):

• CT (computed tomography) colonography, or screening CT colonography, is a non-invasive procedure for detecting cancer in the large intestine.

• This method uses CT scans to generate numerous cross-sectional images, creating a comprehensive view of the colon and rectum.

• Virtual colonoscopy is employed for screening colon cancer, particularly in individuals aged at least 45 or those with suggested health risks.

• Not requiring sedation, the procedure promises patient comfort and is completed in a shorter time than conventional colonoscopy.

• It demonstrates safety advantages over colonoscopy, with lower rates of colon perforation and mortality.

• The technique provides superior visibility of the colon, eliminating blind spots and enabling precise localization of colon lesions.

• Compared to fiber-optic colonoscopy, CT colonography proves more accurate and can also detect clinically important extracolonic abnormalities.

• Limitations include the potential for false-negative results due to the presence of retained fluid, which may obscure lesions.

• The retained stool and nodular folds could be mistaken for polyps, leading to potential false-positive diagnoses.

• A CT colonography does not allow for biopsy or removal of identified polyps, where it can carried out in a traditional colonoscopy.

Multitarget Stool DNA Test:

• The multitarget fecal immunochemical test (FIT) and stool DNA test are home-based screening methods for cancer.

• These tests detect mutation changes and identify blood in stool samples.

• Conveniently, the procedures can be performed at home.

• They specifically identify mutations related to colorectal cancer and the presence of human hemoglobin in the stool.

• The tests are 92 percent sensitive for colorectal cancer detection.

• One positive aspect is that they require only a stool sample, with no need for a special diet or colon preparation.

• The procedures are less sensitive than colonoscopy for detecting precancerous polyps.

• Confirmatory tests may be necessary; false positives occur in 14 percent of cases.

• The tests should be repeated every three years.

• A prescription from a healthcare professional is required to obtain the kit for at-home sample collection.

• The collected sample is sent to the testing company for analysis.

• Results are typically received after about three weeks.

• Positive results may prompt the need for a colonoscopy, while negative results may recommend repeating the test every three years for ongoing colorectal cancer screening.

Enhanced Endoscopic Techniques:

• It improves the visualization of the gastrointestinal tract, ensuring greater accuracy and precision.

• Utilizing high-definition and narrow-band imaging, this approach enhances the detection of colorectal polyps and abnormalities during endoscopic procedures.

• The technique provides a detailed and accurate view, facilitating the proper diagnosis and identification of potential lesions.

• Improved visualization contributes to more effective healthcare interventions, enhancing patient outcomes.

Blood-Based Biomarker Testing:

• Blood-based biomarker testing represents an innovative diagnostic approach for colorectal cancer involving the identification of specific blood biomarkers associated with the disease.

• This non-invasive procedure enables the detection of cancer biomarkers, offering a more convenient and patient-friendly alternative for colorectal cancer screening.

• By analyzing these blood biomarkers, healthcare professionals can efficiently detect the presence of colorectal cancer, allowing for early intervention and improved patient outcomes.

• Blood-based biomarker testing enhances the efficiency of colorectal cancer screening, providing valuable insights without the need for more invasive procedures.

Artificial Intelligence (AI) Integration:

• Artificial intelligence (AI) integration plays a significant role in detecting colorectal cancer through advanced screening methods.

• AI algorithms are employed to analyze radiological and endoscopic findings, offering a faster and more accurate interpretation of results.

• This integration enhances the efficiency of the diagnostic process, aiding in the proper and timely diagnosis of colorectal cancer.

• By using the power of AI, healthcare professionals can make informed decisions, leading to early intervention and more effective treatment strategies.

Capsule Endoscopy:

• Capsule endoscopy offers a non-invasive method for visualizing the GI tract, involving the ingestion of a small capsule equipped with a camera.

• This capsule travels through the digestive system, capturing detailed images of the GI tract and providing a comprehensive view for healthcare professionals.

• Compared to traditional endoscopic methods, capsule endoscopy offers better and more detailed results.

• This patient-friendly alternative reduces discomfort and provides critical diagnostic information, enhancing the overall experience for individuals undergoing the procedure.

Conclusion

Colorectal cancer has become prevalent in the population, influenced by various predisposing factors that impact overall quality of life. Popularizing the significance of early and regular screening for diagnosing the disease in its initial stages allows for the initiation of treatment. Screening methods have been advanced to minimize errors and enhance the ability to detect the presence of polyps or cancerous cells in the early stages.