Bowel Cancer

Bowel cancer, also known as colorectal cancer, is a type of cancer that affects the large intestine (colon) or rectum. It occurs when abnormal cells in the lining of the bowel grow and multiply uncontrollably, forming a tumor.

Types of Bowel Cancer

There are several types of bowel cancer, including:

• Adenocarcinoma: This is the most common type of bowel cancer, accounting for about 95% of cases. It develops from the glandular cells in the lining of the bowel.
• Squamous cell carcinoma: This type of cancer develops from the squamous cells in the lining of the bowel and is more common in the rectum.
• Carcinoid tumors: These are rare, slow-growing tumors that develop from the hormone-producing cells in the bowel.
• Lymphoma: This is a type of cancer that affects the immune system and can occur in the bowel.

Symptoms of Bowel Cancer

The symptoms of bowel cancer can vary depending on the location and size of the tumor. Common symptoms include:

• Blood in the stool or black, tarry stools
• Changes in bowel habits, such as constipation or diarrhea
• Abdominal pain or discomfort
• Weakness or fatigue
• Loss of weight or loss of appetite
• Narrowing of the stool

Causes and Risk Factors of Bowel Cancer

The exact cause of bowel cancer is not known, but there are several risk factors that can increase a person's chance of developing the disease. These include:

• Age: The risk of bowel cancer increases with age, with most cases occurring in people over 50.
• Family history: Having a family history of bowel cancer or other cancers can increase a person's risk.
• Diet: A diet high in red and processed meat and low in fiber can increase the risk of bowel cancer.
• Obesity: Being overweight or obese can increase the risk of bowel cancer.
• Smoking: Smoking can increase the risk of bowel cancer, as well as other cancers.
• Previous radiation therapy: Having previous radiation therapy to the abdomen can increase the risk of bowel cancer.

Diagnosis of Bowel Cancer

Bowel cancer is typically diagnosed using a combination of tests and procedures, including:

• Colonoscopy: A flexible tube with a camera on the end is used to examine the inside of the bowel.
• CT scan: A computerized tomography (CT) scan uses X-rays and computers to create detailed images of the bowel.
• MRI scan: A magnetic resonance imaging (MRI) scan uses magnets and radio waves to create detailed images of the bowel.
• Blood tests: Blood tests can be used to check for signs of cancer, such as anemia or elevated liver enzymes.
• Stool tests: Stool tests can be used to check for blood in the stool or other signs of cancer.

Treatments for Bowel Cancer

The treatment for bowel cancer depends on the stage and location of the tumor, as well as the overall health of the patient. Common treatments include:

• Surgery: Surgery is often used to remove the tumor and surrounding tissue.
• Chemotherapy: Chemotherapy uses medications to kill cancer cells and can be given before or after surgery.
• Radiation therapy: Radiation therapy uses high-energy rays to kill cancer cells and can be given before or after surgery.
• Targeted therapy: Targeted therapy uses medications that specifically target cancer cells and can be used in combination with other treatments.
• Immunotherapy: Immunotherapy uses medications that stimulate the immune system to attack cancer cells and can be used in combination with other treatments.

Stages of Bowel Cancer

Bowel cancer is typically staged using the TNM system, which takes into account the size and location of the tumor (T), the spread of the cancer to nearby lymph nodes (N), and the presence of distant metastasis (M). The stages of bowel cancer are:

• Stage 0: The cancer is limited to the lining of the bowel.
• Stage I: The cancer has grown into the muscle layer of the bowel but has not spread to nearby lymph nodes or distant sites.
• Stage II: The cancer has grown through the muscle layer and into the outer layer of the bowel, but has not spread to nearby lymph nodes or distant sites.
• Stage III: The cancer has spread to nearby lymph nodes but not to distant sites.
• Stage IV: The cancer has spread to distant sites, such as the liver or lungs.

Prognosis of Bowel Cancer

The prognosis for bowel cancer depends on the stage and location of the tumor, as well as the overall health of the patient. Generally, the earlier the cancer is diagnosed and treated, the better the prognosis. The 5-year survival rate for people with bowel cancer is:

• 90% for those with stage I cancer
• 70-80% for those with stage II cancer
• 50-60% for those with stage III cancer
• 10-20% for those with stage IV cancer

Prevention of Bowel Cancer

While there is no sure way to prevent bowel cancer, there are several steps that can be taken to reduce the risk. These include:

• Eating a healthy diet high in fiber and low in red and processed meat
• Getting regular exercise
• Maintaining a healthy weight
• Not smoking
• Limiting alcohol consumption
• Getting screened regularly for bowel cancer, starting at age 50