overview
Colorectal cancer is a type of cancer that affects the colon (large intestine) or rectum. It is one of the most common types of cancer worldwide. This may cause serious harm or death.
The risk of colorectal cancer increases with age. Most cases occur in people over the age of 50.
Common symptoms include diarrhea, constipation, blood in the stool, abdominal pain, unexplained weight loss, fatigue, and low iron levels.
Many people have no symptoms in the early stages of the disease.
The risk of colorectal cancer can be reduced by eating a healthy diet, staying physically active, not smoking, and limiting alcohol. Regular examinations are important for early detection.
Colon cancer is the second leading cause of cancer-related death worldwide. It is estimated that in 2020, there were more than 1.9 million new cases of colorectal cancer and more than 930,000 deaths from colorectal cancer worldwide. Significant geographic variation in incidence and mortality rates was observed. Incidence rates were highest in Europe, Australia, and New Zealand, and mortality rates were highest in Eastern Europe. By 2040, the burden of colorectal cancer is expected to increase to 3.2 million new cases (63% increase) and 1.6 million new cases (73% increase) per year.
Colorectal cancer incidence is decreasing in high-income countries, primarily as a result of effective screening programs. The prognosis for colorectal cancer depends on the stage at the time of diagnosis. Early cancer has a higher survival rate than advanced cancer. Timely diagnosis, appropriate treatment, and regular follow-up care are important to improve survival and quality of life.
Risk factor
Factors that can increase your risk of developing colorectal cancer include:
- Age: The risk of developing colorectal cancer increases with age, with most cases occurring in people over 50.
- Family history: A family history of colorectal cancer or certain genetic diseases, such as Lynch syndrome or familial adenomatous polyposis (FAP), may increase your risk.
- Personal history: People who have previously had colorectal cancer or certain types of polyps are at increased risk.and
- Lifestyle factors: Unhealthy lifestyle choices such as a diet high in processed meat and low in fruits and vegetables, sedentary behavior, obesity, smoking, and excessive alcohol consumption can increase your risk.
symptoms
Colorectal cancer often has no symptoms in its early stages. Regular examinations are important to detect the disease early and begin treatment.
Common symptoms include:
- Changes in bowel habits, such as diarrhea, constipation, or narrowing of the stool
- Blood in the stool (rectal bleeding), either bright red or dark tarry
- Abdominal pain, pain, and bloating that won’t go away
- Unexplained weight loss that occurs suddenly and without effort
- Feeling constantly tired and lacking in energy, even though you are getting enough rest
- Iron-deficiency anemia due to chronic bleeding, causing fatigue, weakness, and pallor.
prevention
Lifestyle changes and regular check-ups can help prevent colorectal cancer.
Lifestyle changes that can help prevent colorectal cancer include:
- Eat a healthy diet rich in fruits and vegetables
- don’t smoke
- maintain an active lifestyle
- limit alcohol intake
- Avoid exposure to environmental risk factors.
Anyone who suspects they have colorectal cancer should talk to their health care provider right away.
Regular screening for colorectal cancer (secondary prevention) is the best way to detect colorectal cancer early.
In the early stages, treatment has a good chance of curing the disease.
Studies have shown that screening can reduce both the incidence and mortality of colorectal cancer by detecting it early and removing precancerous growths.
Stool-based testing is a non-invasive screening method used to detect the presence of colorectal cancer or precancerous polyps in the stool. A common type of stool-based test is the fecal occult blood test (FOBT). FOBT detects hidden blood in the stool, which can be an indicator of colorectal cancer or polyps. This involves collecting a small stool sample and sending it to a laboratory for analysis. If blood or abnormal findings are detected in the stool, further diagnostic procedures, such as a colonoscopy, are usually recommended to confirm the presence of colorectal cancer or polyps.
Stool-based tests are convenient, non-invasive, and effective in detecting colorectal cancer early and identifying precancerous polyps.
People with a family history of colorectal cancer or certain genetic conditions may benefit from genetic counseling and genetic testing to assess risk and determine appropriate screening methods.
diagnosis
Diagnosis of colorectal cancer includes a physical examination, imaging tests (such as abdominal ultrasound, computed tomography scans, and magnetic resonance imaging), and examination of the inside of the colon using colonoscopy or sigmoidoscopy. Laboratory tests, tissue sample collection for histopathology (biopsy), and molecular testing can identify specific genetic mutations and biomarkers to guide optimal treatment options.
treatment and care
Treatment of colorectal cancer is based on the type and stage of the cancer and the patient’s medical history. Early detection of colorectal cancer can lead to better treatment and outcomes.
Treatments include:
- surgery
- Radiotherapy (radiation)
- chemical treatment
- targeted therapy
- Immunotherapy.
Surgery is often used in the early stages of cancer if the tumor has not spread to other areas of the body. Chemotherapy and radiation therapy can help shrink the tumor.
Physicians from multiple specialties often work together to provide treatment and care for patients with colorectal cancer.
Supportive care is important for patients with colorectal cancer. It aims to manage symptoms, reduce pain and provide emotional support. Helps improve the quality of life for colorectal cancer patients and their families.
stages of care
a) Early stage disease. The main treatment for early colorectal cancer (i.e., when the tumor is confined to the intestine or local lymph nodes and has not spread to distant organs) is surgical removal of the tumor and nearby lymph nodes. The specific surgical procedure depends on the location of the tumor. This may include a colectomy (removal of part of the colon) or a proctectomy (removal of the rectum). In some cases, a temporary or permanent colostomy or ileostomy may be necessary to create an opening for waste removal. Adjuvant therapy refers to additional treatment given after surgery to reduce the risk that the cancer will come back. For early colorectal cancer, adjuvant chemotherapy may be recommended to kill any remaining cancer cells that cannot be seen or removed during surgery. Adjuvant chemotherapy is usually recommended for patients at high risk of recurrence, such as those with lymph node metastases or certain tumor characteristics. In some cases, chemotherapy may be given before surgery to shrink the tumor (preoperative chemotherapy). For tumors in the last part of the intestine (rectum), radiation therapy may increase the chance of reducing tumor size.
After treatment, regular follow-up visits and monitoring are essential to watch for signs of recurrence or new cancer. Surveillance may include physical exams, blood tests, and imaging tests (such as CT scans) to detect possible recurrence at an early stage.
a) Advanced disease. Systemic therapy is the main treatment approach for metastatic colorectal cancer that aims to treat cancer cells throughout the body. Chemotherapy is often used as first-line treatment for metastatic colorectal cancer. Combination chemotherapy is commonly used to kill cancer cells or slow their growth. Targeted therapy may be used in combination with chemotherapy for patients with certain genetic mutations, such as KRAS mutations or BRAF mutations. Immunotherapy drugs may be considered for patients whose tumors exhibit certain genetic markers such as microsatellite high instability (MSI-H) and mismatch repair deficiency (dMMR).
In some cases, surgery may be recommended for metastatic colorectal cancer to remove a tumor that is causing symptoms or blocking the intestine. Local treatments such as radiofrequency ablation, cryoablation, or radiation therapy may be used to treat specific areas of metastases, such as liver metastases. Radiation therapy may be used to control the disease and manage symptoms such as pain and bleeding.
clinical trial
Clinical trials provide patients with access to new or experimental treatments. Participation in clinical trials helps advance medical knowledge and may provide new treatment options.
WHO response
WHO is actively working to implement strategies to address the global burden of colorectal cancer and reduce its impact. WHO’s approach includes raising awareness, cancer prevention and control, early detection and screening, strengthening health systems, capacity building, research and surveillance, and cooperation and partnerships. These comprehensive efforts will reduce the burden of colorectal cancer by promoting prevention, early detection, and equitable access to quality care, and improving overall cancer control globally. I will contribute to that.