Colon Cancer

Symptoms: changes in bowel habits, diarrhoea, constipation, blood in the stool, abdominal pain, unexplained weight loss, fatigue, low iron levels.

Risk Factors: Colon polyps, age, family history, and lifestyle changes.

Severity: Mild to Severe.

Gender affected: Both male and female populations can get affected but more common in men.

Which doctor to consult: A general physician, oncologist, gastroenterologist.

Overview: 

Colon cancer, also known as colorectal cancer, is a type of cancer that begins in the large intestine (colon). It’s the third most common cancer worldwide and the second leading cause of cancer-related deaths. Colon is the last and lowest segment of the digestive system where the body extracts salt and water from solid waste.

The common symptoms of colon cancer include changes in bowel habits, diarrhoea, constipation, blood in the stool, abdominal pain, unexplained weight loss, fatigue, low iron levels, etc. The major risk factor of colon cancer is colon polyps. The other risk factors include age, family history, and lifestyle changes.

Early signs and symptoms of cancer may not be present in colon polyps or early cancer. Regular colorectal cancer screening is crucial as a result. Colonoscopy (a procedure which show the whole colon), and biopsy (to identify the malignant tissue) are the screening procedures used to diagnose colon cancer.

The treatment of colon cancer mainly depends on the location, size, stage, and the extent to which the cancer has spread. It includes surgery, radiation therapy, immunotherapy and chemotherapy. Surgery is used to remove the tumour while colon cancer is still in its early stages. It can spread to other bodily parts, particularly the liver and lungs if treatment is delayed.

Types of Colon Cancer:

The term colon cancer primarily refers to colorectal adenocarcinomas, which are the most common type. However, there are several other types of colon cancer, each with unique characteristics and treatment approaches.

Adenocarcinomas: The vast majority of colon cancers are adenocarcinomas, which start in the cells lining the inside surface of the colon.

Carcinoid Tumors: These begin in hormone-producing cells within the intestines.

Gastrointestinal Stromal Tumors (GISTs): Though rare in the colon, GISTs can occur anywhere in the gastrointestinal tract.

Lymphomas: Typically starting in the lymph nodes, lymphomas can also originate in the colon.

Hereditary Colon Cancers: Between 5 to 10 percent of colon cancers are due to genetic mutations passed from parents to children, known as hereditary colon cancers.

Rare Types: Other less common types include leiomyosarcomas, melanomas, and neuroendocrine tumors.

Each type may require a different treatment strategy, so it’s important for a diagnosis to specify the type of colon cancer. For anyone seeking more detailed information or facing a diagnosis, consulting with healthcare professionals is essential. They can provide personalized information based on the individual’s medical history and the specific characteristics of their cancer.

Symptoms:

The symptoms of colon cancer can vary and may not always be noticeable, especially in the early stages. However, here are some common symptoms to be aware of:

• Changes in bowel habits: This can include diarrhoea, constipation, or a change in the consistency of your stool that lasts for more than a few days.

• Rectal bleeding or blood in the stool: This is a common symptom and can appear as bright red or very dark blood.

• Persistent abdominal discomfort: Such as cramps, gas, or pain.

• A feeling that your bowel doesn’t empty completely: This sensation may persist even after a bowel movement.

• Weakness or fatigue: This can be due to anaemia caused by a slow bleed in the colon, which is not always visible.

• Unexplained weight loss: Losing weight without trying can be a sign of colon cancer.

It’s important to note that these symptoms can also be caused by other, less serious conditions. If you experience any of these symptoms, it’s a good idea to consult a healthcare provider. They can help determine the cause and whether any further testing or treatment is needed. If you’re over 50 or have a family history of the disease, it’s especially important to discuss screening options with your doctor.

Causes:

Colon cancer, also known as colorectal cancer, is a type of cancer that begins in the large intestine (colon), which is the final part of the digestive tract. The main causes of colon cancer include:

Genetic Mutations: Most colon cancers are believed to start from noncancerous polyps in the colon. Over time, some of these polyps can acquire genetic mutations that may eventually lead to cancer. These mutations cause the cells to multiply uncontrollably, creating a tumor.

Inherited Gene Mutations: A small percentage of colon cancers are linked to inherited gene mutations. These hereditary syndromes include familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC), also known as Lynch syndrome. These conditions can be detected through genetic testing.

Lifestyle Factors: Several lifestyle factors have been linked to an increased risk of developing colon cancer, including:

• A diet high in red and processed meats
• Low fiber intake
• Obesity
• Sedentary lifestyle
• Smoking
• Excessive alcohol consumption

Age and Health Conditions: The risk of colon cancer increases with age, particularly after the age of 50. Other health conditions, such as chronic inflammatory diseases of the colon like Crohn’s disease or ulcerative colitis, can also increase the risk.

Ethnicity and Family History: African-Americans have a higher risk of colon cancer. Additionally, having a family history of colon cancer or polyps can increase an individual’s risk.

Environmental Factors: Exposure to certain environmental factors, such as radiation, may also contribute to the risk of developing colon cancer.

It’s important to note that many people with colon cancer experience no symptoms in the early stages, which is why screening is crucial for early detection. If you have concerns about colon cancer or are experiencing symptoms, it’s essential to consult a healthcare professional for proper diagnosis and treatment.

Remember, while the exact cause of colon cancer may not be known, understanding the risk factors can help in taking preventive measures and making informed decisions about your health.

Risk factors:

Understanding the risk factors for colon cancer can help in taking preventive measures. Here are the key risk factors:

• Age: The risk of colon cancer increases with age, especially after age 50.

• Family History: Having a first-degree relative (parent, sibling, or child) with colon cancer.

• Personal Health History: A personal history of colorectal cancer or polyps. A personal history of inflammatory intestinal conditions, such as ulcerative colitis or Crohn’s disease.

• Inherited Syndromes: Genetic syndromes passed through generations, such as familial adenomatous polyposis (FAP) or Lynch syndrome (hereditary nonpolyposis colorectal cancer, HNPCC).

• Diet:

  • A diet high in red meats and processed meats can increase the risk.

  • Low-fiber, high-fat diets have also been linked with a higher risk.

• Lifestyle Factors:

  • Physical inactivity.

  • Obesity.

  • Smoking.

  • Heavy alcohol use.

• Racial and Ethnic Background:

  • African Americans have a greater risk of colon cancer than other races.

  • Jews of Eastern European descent (Ashkenazi Jews) may have a higher rate of colon cancer.

• Type 2 Diabetes: People with diabetes or insulin resistance have an increased risk of colon cancer.

• Radiation Therapy: Radiation therapy directed at the abdomen to treat previous cancers.

It’s important to discuss these risk factors with a healthcare provider, especially if you believe you may be at risk. They can provide guidance on screening options and lifestyle changes that may help reduce the risk of colon cancer.

Complications:

Colon cancer can lead to several serious complications, especially if not detected and treated early. Here are some of the potential complications associated with colon cancer:

• Bowel Obstruction: Colon cancer can grow large enough to block the inside of the colon, leading to bowel obstruction. This can cause symptoms like severe abdominal pain, constipation, and bloating.

• Metastasis: Cancer cells can spread from the colon to other parts of the body, such as the liver or lungs. This process is known as metastasis and can significantly affect the treatment approach and prognosis.

• Anemia: Chronic blood loss from the cancer can lead to anemia, which can cause fatigue, shortness of breath, and other symptoms related to a decrease in red blood cells.

• Perforation: In some cases, the cancer can grow through the wall of the colon and create a hole, leading to a serious condition called perforation. This can cause the contents of the colon to spill into the abdominal cavity, leading to peritonitis, an inflammation of the lining of the abdominal cavity.

• Increased Risk of Infections: Colon cancer and its treatment can weaken the immune system, increasing the risk of infections.

• Secondary Cancers: Patients with colon cancer may have an increased risk of developing a second primary colorectal cancer.

It’s important to note that not everyone with colon cancer will experience these complications, and the risk can vary based on the stage of cancer, overall health, and treatment plan. Regular screenings and early detection are key to preventing complications and improving outcomes.

Prevention:

Preventing colon cancer involves a combination of lifestyle changes, regular screening, and being aware of your personal and family medical history. Here are some detailed strategies for colon cancer prevention:

• Screening: Regular screening is crucial as it can detect polyps before they become cancerous. It’s recommended to start screening for colorectal cancer at age 45 or older. Types of screening tests include colonoscopy, stool tests, and CT colonography. Discuss with your healthcare provider which test is suitable for you.

• Diet and Nutrition: Eating a diet high in vegetables, fruits, and whole grains, and low in red and processed meats may help lower the risk of colon cancer. Limiting red and processed meats, and eating more plant-based foods can decrease your risk.

• Physical Activity: Increasing physical activity can lower the risk of colorectal cancer. Aim for regular moderate to vigorous activity

• Weight Management: Being overweight or obese increases the risk, especially in men. Maintaining a healthy weight may help reduce the risk.

• Alcohol and Smoking: Limit alcohol consumption to no more than one drink per day for women and two for men. Quit smoking, as tobacco use is associated with an increased risk of colon cancer.

• Genetic Counseling: If you have a strong family history of colorectal polyps or cancer, consider genetic counselling to understand your risk and take appropriate preventive measures.

Remember, while you can’t control certain risk factors like age and family history, adopting healthy lifestyle choices can significantly reduce your risk of developing colon cancer. Always consult with your healthcare provider for personalized advice and recommendations.

When to visit a doctor:

It’s important to visit a general physician, oncologist or gastroenterologist for colon cancer concerns if you experience any of the following symptoms, especially if they persist:

• Changes in bowel habits, such as diarrhoea or constipation, that last more than a few days

• Rectal bleeding or blood in your stool

• Persistent abdominal discomfort, such as cramps, gas, or pain

• A feeling that your bowel doesn’t empty completely

• Weakness or fatigue

• Unexplained weight loss

Additionally, if you have a family history of colon cancer or other risk factors, discussing screening options with your healthcare provider is crucial. Regular screening is recommended starting at age 45 for those at average risk. If you’re experiencing any of the symptoms mentioned or have concerns about your risk of colon cancer, don’t hesitate to schedule an appointment with your doctor. 

Diagnosis:

The diagnosis of colon cancer typically involves a series of steps and tests to confirm the presence of cancer cells in the colon. Here’s a detailed overview of the diagnostic process:

Initial Evaluation:

• Medical History and Physical Exam: Your doctor will start by asking about your symptoms, family history, and personal health history. A physical exam may include a digital rectal exam (DRE).

Diagnostic Tests:

• Colonoscopy: The most comprehensive test for diagnosing colon cancer. A long, flexible tube with a camera is used to examine the entire colon and rectum.

• Biopsy: During a colonoscopy, if suspicious areas are found, a biopsy is performed to remove tissue samples for analysis under a microscope.

Imaging Tests:

• CT or CAT Scan: Provides detailed cross-sectional images of the body to detect any abnormalities or spread of cancer.

• MRI: Offers detailed images and is particularly useful for seeing soft tissues and organs.

• Ultrasound: May be used to look at the liver if metastasis is suspected.

Blood Tests:

• Complete Blood Count (CBC): To check for anemia which can be caused by bleeding from the tumor.

• Liver Enzymes: To assess liver function, which can be affected by the spread of cancer cells.

• Carcinoembryonic Antigen (CEA) Test: Measures the level of CEA in the blood, which may be elevated in people with colon cancer.

Staging:

After diagnosis, staging tests determine the extent of cancer in the body. Staging helps guide treatment decisions and includes additional imaging tests like PET scans. The following stages of colon cancer development occur gradually:

• Stage 0 (cancer in situ): The colon's inner lining is the only place where the cancer cells are found.

• Stage I: The colon's or rectum's muscular layer is attacked by the cancer cells.

• Stage II A: The tumor begins to spread into the colon's or rectum's outermost layers.

• Stage II B: The tumor begins to spread into the colon's or rectum's innermost layers.

• Stage II C: The tumor begins to encroach into neighbouring tissues.

• Stage III A: The tumor begins to develop into the intestinal muscle layers and invades one to three surrounding lymph nodes.

• Stage III B: The tumor begins to spread to nearby organs, lymph nodes, and the intestinal wall.

• Stage III C: Four or more lymph nodes have been affected by the malignancy.

• Stage IV A: The cancer has progressed to a remote area of the body, like the liver or lungs.

• Stage IV B: The cancer has progressed to multiple remote organs.

• Stage IV C: The abdominal cavity lining has been affected by the malignancy.

All people between the ages of 45 and 75 are advised to get colon cancer screening tests. People over 75 or those with greater risk profiles should speak with their doctor about screening.

Stool based test:

These tests look for any indications of colon cancer in the stool. Because they may be done at home by patients, they are simpler than colonoscopies. However, if stool-based testing yield good results, a colonoscopy is advised. This comprises:

• Fecal immunochemical test (FIT): This test uses antibodies to find blood that may be concealed in the feces. Utilizing a kit that your healthcare practitioner provides, the stool is collected at home.

• Guaiac-based fecal occult blood test (gFOBT): This test looks for blood in the stool by utilizing guaiac, a chemical. A home kit is used to gather the sample, which is subsequently tested in a laboratory. Certain medicines and diets have an impact on the outcome of gFOBT tests. Therefore, anyone taking this test should avoid

1. NSAIDs, such as aspirin and ibuprofen, seven days before testing because of their propensity to cause bleeding.

2. Three to seven days before to the test, avoid consuming vitamin C—either from citrus fruits or supplements—as this may interfere with the chemical utilized.

3. Red meat because it may produce erroneous positive findings.

Molecular Testing of the Tumor:

• Genetic Tests: Can identify specific mutations in the cancer cells that may affect the prognosis and treatment.

It’s important to note that not all tests may be necessary for every individual. The choice of diagnostic tests depends on the symptoms, medical history, and results of earlier medical tests. Remember, if you suspect you have symptoms of colon cancer, please consult a healthcare professional for an accurate diagnosis and appropriate treatment plan.

 Treatment:

The treatment of colon cancer typically involves a combination of approaches tailored to the individual’s specific condition, including the stage of cancer, location, and overall health. Here’s a detailed overview of the treatment options:

Surgery:

• Colonoscopy: To remove small localized cancers or polyps during the early stages

• Partial Colectomy: Surgical removal of part of the colon that contains cancer, along with a margin of normal tissue on either side of the cancer.

• Laparoscopy: Minimally invasive surgery to remove polyps that cannot be removed during a colonoscopy.

• Bowel Resection with Colostomy: For cancers that cannot be reconnected, a colostomy may be necessary.

Chemotherapy:

Used to destroy cancer cells, often after surgery to eliminate any remaining cancer cells and reduce the risk of recurrence.

Medications like 5-Fluorouracil, Capecitabine, Irinotecan, and Oxaliplatin are commonly used.

Radiation Therapy:

Uses high-energy beams, such as X-rays, to destroy cancer cells. It’s often used in conjunction with chemotherapy before or after surgery.

Targeted Drug Therapy:

Targets specific abnormalities within cancer cells. Drugs like Bevacizumab and Ramucirumab are examples of targeted therapies.

Immunotherapy:

Utilizes the body’s immune system to fight cancer. Drugs like Nivolumab and Pembrolizumab may be used for cancers that respond to these treatments.

Supportive Care:

Includes pain management, nutritional support, and other therapies to help manage symptoms and side effects of cancer treatment.

Dietary Considerations:

A low-fat, high-fiber diet with plenty of fruits and vegetables is recommended. Antioxidants found in foods like kidney beans and berries may also be beneficial.

Health Warning:

If you or someone you know is exhibiting symptoms of colon cancer, seek medical attention immediately.

It’s important to discuss all treatment options, including potential side effects and the likelihood of curing the cancer or providing relief from symptoms, with your healthcare provider.