Colorectal cancer is a disease that specifically affects the colon or rectum. These organs are part of the large intestine. This type of cancer develops from an abnormal growth of cells that form a tumor. Early screening and detection significantly increase the chances of successful treatment. Therefore, a better understanding of this disease for everyone is essential.

Causes and Risk Factors for Colorectal Cancer

Colorectal cancer often results from a combination of genetic and environmental factors. Although the exact cause is most often not identifiable, several elements increase the risk of developing this disease.

Genetic and Hereditary Factors

• Family History: The risk increases if close relatives (parents, siblings, children) have had colorectal cancer or adenomatous polyps.
• Genetic Syndromes: Certain hereditary genetic mutations significantly increase the risk. Lynch syndrome and familial adenomatous polyposis (FAP) are the most common examples. These syndromes cause the development of many polyps that can evolve into cancers.

Lifestyle Factors

• Diet: A diet rich in red and processed meats, and low in fiber, is associated with an increased risk.
• Sedentary Lifestyle: Lack of physical activity also contributes to the risk.
• Obesity: Overweight and obesity increase the risk of many diseases, including colorectal cancer.
• Smoking and Alcohol: Smoking and excessive alcohol consumption damage cells and increase the risk of cancer.

Pre-existing Medical Conditions

• Inflammatory Bowel Diseases: Untreated Crohn’s disease or ulcerative colitis increase the risk of colorectal cancer. Regular monitoring is necessary for affected individuals.
• Intestinal Polyps: Most colorectal cancers begin as benign growths called polyps. Some types, especially adenomas, can become cancerous over time. Their screening and removal prevent cancer development.

Symptoms and Signs of Colorectal Cancer

The symptoms of colorectal cancer vary depending on the tumor’s location and stage. They can also be subtle or absent in the early stages. This emphasizes the importance of regular screening.

Early and Persistent Signs

• Changes in Bowel Habits: Persistent changes such as diarrhea, constipation, or alternating between the two. Sometimes stools are thinner than usual.
• Rectal Bleeding or Blood in Stools: The presence of bright red or very dark blood in the stools requires immediate medical consultation.
• Abdominal Pain or Cramps: Persistent pain, excessive gas, bloating, or discomfort in the abdomen.

Advanced Symptoms

• Unexplained Weight Loss: Rapid and unexplained weight loss accompanies more advanced stages of the disease.
• Fatigue and Weakness: Chronic blood loss can lead to anemia, causing general fatigue and weakness.
• Feeling of Incomplete Bowel Emptying: Also known as tenesmus, this sensation is a possible sign, especially if the tumor is located in the rectum.

It is important to note that these symptoms are not specific to colorectal cancer; other less serious conditions also cause them. However, their persistence always warrants medical advice.

Diagnosis of Colorectal Cancer: How is it Detected?

Accurate and rapid diagnosis is crucial for effective colorectal cancer treatment. Doctors use several methods to identify the disease and determine its stage.

Screening and Initial Examinations

• Fecal Immunochemical Test (FIT): This simple home-based test looks for traces of blood not visible to the naked eye. Widespread screening programs often use this test to identify at-risk individuals.
• Colonoscopy: If the FIT is positive or in the presence of symptoms, colonoscopy is the reference examination. The doctor inserts a thin, flexible tube equipped with a camera to visualize the inside of the colon and rectum. They remove polyps or perform biopsies if necessary.
• Flexible Sigmoidoscopy or Rectoscopy: These examinations, similar to colonoscopy, only explore the lower part of the colon (rectum and sigmoid).

Additional Examinations

• Blood Tests: Chemical blood tests measure tumor markers, such as carcinoembryonic antigen (CEA), for disease monitoring or evaluating treatment effectiveness.
• Medical Imaging: CT scans, MRIs, or PET scans evaluate the extent of the cancer, look for metastases, and guide treatment decisions.

The combination of these examinations helps doctors make an accurate diagnosis and develop a treatment strategy adapted to each patient.

Treatments and Management of Colorectal Cancer

The management of colorectal cancer depends on many factors such as the stage of the disease, the tumor’s location, and the patient’s general condition. A multidisciplinary approach is often preferred.

Common Therapeutic Options

• Surgery: The removal of the tumor and part of the colon or rectum is the primary treatment method for colorectal cancers. Surgeons remove nearby lymph nodes to analyze their possible involvement.
• Chemotherapy: Anticancer drugs target tumor cells. Chemotherapy can precede surgery (neoadjuvant chemotherapy) to reduce tumor size, or follow it (adjuvant chemotherapy) to eliminate remaining cells and prevent recurrence. Doctors also use it for metastatic cancers.
• Radiation Therapy: The use of high-energy rays destroys cancer cells. Radiation therapy is more often applied for rectal cancers, before or after surgery.
• Targeted Therapies: These drugs act on specific characteristics of cancer cells, blocking their growth or spread. They are often used in combination with chemotherapy for advanced cancers.
• Immunotherapy: This approach boosts the patient’s immune system to recognize and fight cancer cells. Immunotherapy is particularly effective for certain types of colorectal cancers with specific genetic alterations.

Personalized Treatment

The medical team always customizes the treatment plan. It takes into account the specificities of the cancer and the patient’s preferences. Psychological and nutritional support often complement treatments to improve quality of life.

Recent Scientific Advances in Colorectal Cancer

Research on colorectal cancer is constantly progressing, offering new perspectives in diagnosis and treatment. Recent advances focus particularly on non-invasive screening and improving treatment personalization.

• Liquid Biopsies: Recent studies explore the use of liquid biopsies for disease monitoring. They allow the detection of circulating tumor DNA in the blood. They detect recurrences earlier and evaluate treatment effectiveness in a less invasive way.
• Artificial Intelligence in Histopathology: Artificial intelligence (AI) helps in the analysis of histological slides. It identifies biomarkers and tumor characteristics with increasing accuracy. This technology improves the diagnosis and classification of colorectal cancers, guiding more targeted treatments.
• Immunotherapy Combinations: Researchers are exploring new combinations of immunotherapies and targeted therapies. Preliminary results show increased efficacy for specific subtypes of colorectal cancer, including those resistant to conventional treatments. These approaches aim to overcome resistance mechanisms and improve antitumor immune response.

These promising developments, although often still in the research or clinical trial phase, highlight the scientific community’s continuous commitment to revolutionize colorectal cancer management.

Colorectal Cancer Prevention: Is It Possible to Reduce the Risk?

Yes, it is possible to reduce the risk of colorectal cancer. Several preventive measures, mainly related to lifestyle and screening, can limit the likelihood of developing this disease.

Lifestyle Measures

• Balanced Diet: Consume more fruits, vegetables, and whole grains. Limit the consumption of red and processed meats. Dietary fiber plays an important protective role.
• Regular Physical Activity: Incorporate at least 30 minutes of moderate activity most days of the week. This helps maintain a healthy weight and reduces inflammation.
• Maintain a Healthy Weight: Obesity is a recognized risk factor. Achieving or maintaining a healthy weight decreases the risks.
• Limit Tobacco and Alcohol: Avoid smoking and moderate your alcohol consumption to significantly reduce your risk of colorectal cancer.

Importance of Screening

• Organized Screening: Regular screening is essential, especially from age 50. Colorectal cancer screening programs detect polyps or cancers at an early stage, often before symptoms appear.
• Surveillance Colonoscopy: For individuals at increased risk (family history, inflammatory bowel diseases), regular colonoscopy surveillance can detect and remove polyps before they become malignant.

Adopting these healthy lifestyle habits and participating in screening programs effectively reduces the risk of developing colorectal cancer and improves the prognosis in case of detection.

Living with Colorectal Cancer

Living with colorectal cancer, during and after treatment, represents a major challenge. Support, side effect management, and regular follow-up are essential to maintain a good quality of life.

Side Effect Management

• Pain: Medications and relaxation techniques help control pain related to cancer or its treatments.
• Fatigue: Fatigue is common. Adjust your schedule and seek professional help to better manage it.
• Digestive Problems: Surgery and chemotherapy can alter intestinal transit. A team of nutritionists and gastroenterologists implements dietary measures to manage it.
• Ostomy: Some people require a temporary or permanent ostomy. Support from an ostomy nurse helps to adapt to this new situation.

Support and Resources

• Psychological Support: Talking to a psychologist or joining a support group helps manage anxiety, depression, or stress.
• Family and Social Support: Support from loved ones is often indispensable. Do not hesitate to ask for their help or turn to patient associations.
• Professional Reintegration: Measures exist to support reintegration into professional life, if desired and possible.

Long-term Follow-up

• Regular Consultations: Regular follow-up visits are essential to monitor for any recurrence or the appearance of new problems.
• Imaging Examinations: Scans or other imaging examinations allow monitoring of the disease’s evolution.
• Hygiene and Lifestyle: Maintaining a balanced diet and regular physical activity contributes to overall well-being and reduces the risk of recurrence.

Frequently Asked Questions (FAQ)

Q.1. What is a colorectal polyp?

A colorectal polyp is an outgrowth of tissue that forms on the inner wall of the colon or rectum. Most polyps are benign, but some, called adenomas, can evolve into cancer over time. Doctors remove them during a colonoscopy to prevent cancer development.

Q.2. Is colorectal cancer hereditary?

Colorectal cancer can have a hereditary component. Approximately 5% to 10% of cases involve specific genetic syndromes, such as Lynch syndrome or familial adenomatous polyposis. A family history of the disease also increases the risk. Talk to your doctor for a personalized risk assessment.

Q.3. At what age should I start colorectal cancer screening?

Colorectal cancer screening generally starts from age 50 for the general population and is recommended every two years. If risk factors exist (family history, inflammatory bowel diseases), your doctor may recommend earlier or more frequent screening.

Q.4. What are the main avoidable risk factors?

The main avoidable risk factors are smoking, excessive alcohol consumption, a diet rich in red and processed meats and low in fiber, lack of physical activity, and obesity. Adopting a healthy lifestyle significantly reduces the risk.

Q.5. What foods should I prioritize to prevent colorectal cancer?

Prioritize a fiber-rich diet: fruits, vegetables, legumes, whole grains. Limit red meats, processed meats, and ultra-processed foods. A healthy and varied diet contributes to the prevention of many cancers.

Additional Resources

• Mayo Clinic

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