Colon Cancer – What do you need to know?

What Is Colon Cancer?

Colon cancer, also known as colorectal cancer, is one of the most common forms of cancer. It originates in the colon or rectum, often as a growth called a polyp. Over time, these polyps can become cancerous, making it crucial to detect and treat them early. This cancer can be highly aggressive, spreading to other parts of the body if not diagnosed and treated in its early stages. Colorectal cancer (CRC) is the third most common cause of death for both men and women. It is most frequently diagnosed among persons aged 65 to 74, and approximately 10.5% of new colorectal cancer cases occur in people under 50.

Colon Cancer Risk Factors

The exact cause of colon cancer is not fully understood, but certain risk factors can increase your likelihood of developing the disease. They are discussed below:

Non-modifiable risk factors of colon cancer:

These are the risk factors you do not have control over. They are factors that you are born with, and you cannot do anything to modify them to decrease the risk.

• Age: The rate of CRC increases with age, and nearly 94% of new cases of CRC occur in adults 45 years or older.
• Ethnicity: Studies have shown that the rates of colorectal cancer incidence are higher in certain ethnic groups such as black, American Indian, and Alaskan natives. The reason for this higher incidence is unclear; these adults are at increased risk of developing CRC.
• Family History: A person with a family history of colorectal cancer is at higher risk. Sadly, you do not need to have known inherited syndromes like lynch or familial adenomatous polyposis to have the heightened risk.
• Inherited gene mutations: Rare genetic mutations, such as APC, MUTYH, or DNA mismatch repair gene mutations, can increase the risk of colon cancer.

Modifiable risk factors of colon cancer:

These are risk factors that you can modify through behavioral, medical, or environmental interventions. Some of the modifiable risk factors of colorectal carcinoma are:

• Diet: A diet high in red and processed meats, as well as low in fiber, fruits, and vegetables, is associated with an increased risk of colon cancer.
• Obesity: It has been found that excess body weight, particularly around the waist, is linked to an increased risk of colon cancer. Regular exercise and weight management can help lower this risk.
• Physical Inactivity: A sedentary lifestyle has been shown to contribute to a higher risk of colon cancer.
• Alcohol Consumption: Heavy alcohol consumption is associated with an elevated risk of colon cancer. It’s advisable to consume alcohol in moderation or abstain from it.
• Smoking: Smoking is a common risk factor for numerous cancers, including colon cancer.
• Inflammatory Bowel Disease (IBD): Conditions like Crohn’s disease and ulcerative colitis have increased the risk of colon cancer.

Colon Cancer Symptoms

Colorectal cancer may not present with symptoms in its early stage and can reach a point where it might be difficult to cure. It is essential to keep note of the symptoms that can help to detect these cancers in their early stage.

1. Changes in Bowel Habits:

• Unexplained Constipation: If you’ve noticed persistent and unexplained changes in your bowel movements, such as constipation, that won’t resolve with dietary changes or laxatives, it could be a sign of colorectal cancer.
• Chronic Diarrhea: On the flip side, persistent diarrhea can also be a red flag, especially if it lasts several weeks or occurs with other symptoms.
• Alterations in Stool Consistency: Keep an eye on your stool consistency. Thin or pencil-like stools, sometimes compared to “pencil-thin” in appearance, may indicate a blockage or tumor in the colon.

2. Blood in the Stool:

• Visible Blood: Perhaps one of the most unmistakable signs, seeing bright red blood in your stool or on toilet paper can be alarming and warrants immediate attention.
• Dark or Tarry Stools: Blood that’s been digested may turn your stool dark or black. This can be a sign of bleeding higher up in the digestive tract.

3. Abdominal Discomfort: Colorectal cancer can cause cramps or aches in your lower abdomen that don’t seem to go away, even with over-the-counter remedies.

4. Unexplained Weight Loss: If you’re shedding pounds without trying, it could be due to changes in your digestive system caused by cancer.

5. Iron-Deficiency Anemia: This occurs when your body doesn’t have enough iron, often due to chronic bleeding in the colon. Symptoms may include weakness, paleness, and shortness of breath.

6. Feeling of Incomplete Evacuation: You may feel the need to have a bowel movement but can’t empty your bowels. This can be one of the signs of colon cancer.

CRC( colorectal Cancer) Screening

Colorectal cancer, when caught early, is highly treatable and often curable. Screening for colorectal cancer is a proactive step that can make all the difference in the world.

Q. Who should be screened?

Screening guidelines typically recommend that individuals at average risk for colorectal cancer begin screening at age 45. However, the age at which screening should begin may vary based on individual risk factors, family history, and genetics. Those with a family history of colorectal cancer or certain genetic syndromes may need to start screening earlier.

Colon Cancer Screening Guidelines

Screening methods

• Fecal Occult Blood Test (FOBT): This non-invasive test checks for hidden blood in the stool, possibly indicating colorectal cancer.
• Fecal Immunochemical Test (FIT): It is a similar test to FOBT, and FIT specifically detects blood from the lower digestive tract.
• Colonoscopy: This is considered the gold standard for colorectal cancer screening. It involves thoroughly examining the entire colon and rectum using a long, flexible tube with a camera. Polyps can be removed during the procedure.
• Sigmoidoscopy: This procedure examines the lower part of the colon. It is similar to colonoscopy; however, the part it examines is limited to the sigmoid colon.

Screening frequency

• The frequency of screening depends on the method used and individual risk factors.
• For most people at average risk, colonoscopy is typically recommended every 10 years.
• Stool-based tests like FOBT and FIT may be done annually.

Colon Cancer Diagnosis

Your doctor might employ various ways to detect and diagnose the presence of the carcinoma. Here is the list of tests that your doctor might suggest:

1. Blood tests: Blood tests play a crucial role in the detection and monitoring of various medical conditions that you have, including colorectal cancer. It is important to remember that blood markers are not diagnostic on their own and are used as a part of a comprehensive assessment. The test includes:

• Tumor marker: Carcinoembryonic antigen (CEA) is the most widely recognized blood marker for colorectal cancer. CEA is primarily used for monitoring disease progression, treatment response, and detecting disease recurrence. However, elevated CEA levels may indicate the presence of other cancers, including lung, breast, and pancreatic cancer, and it can also be elevated in non-cancerous conditions, such as inflammation or smoking.
• Genetic and Molecular Markers: Advances in molecular biology have led to the identification of genetic and molecular markers, such as mutations in genes like KRAS, NRAS, and BRAF. These markers help predict treatment responses to targeted therapies and immunotherapies in colorectal cancer patients.
• Complete Blood Count (CBC): These routine blood tests can provide information about overall health, including detecting anemia and deranged liver and kidney function, which can be affected by colorectal cancer or its treatment.

2. Colonoscopy and biopsy: colonoscopy is a procedure that utilizes a flexible tube with a camera that offers real-time visualization of the colon and rectum, enabling the detection of precancerous polyps and tumors. If your doctor detects abnormalities, biopsy samples can be obtained during the procedure, allowing for a definitive diagnosis by examining the tissue under a microscope. These crucial steps confirm the presence of colorectal cancer, determine its type stage, and guide treatment decisions.

3. Imaging: Various imaging techniques are employed in the context of colorectal cancer. Computed Tomography (CT) scans provide detailed cross-sectional images of the abdomen and pelvis, making them useful for staging and monitoring response to treatment. Magnetic Resonance Imaging (MRI) offers high-resolution images of the pelvis, aiding in assessing the local extent of the tumor and lymph node status. Positron Emission Tomography (PET) scans detect distant metastases and assess the metabolic activity of lesions, enhancing staging accuracy when combined with CT or MRI. Ultrasound is utilized for assessing rectal tumors, providing real-time imaging during certain procedures. Not everyone requires all the tests; your doctor will suggest the right test for you.

Colon Cancer Treatment

There are various treatment options available for colorectal cancer, and they depend on numerous factors, including the location of the tumor, tumor stage, overall health, and many more.

Here is the list of treatment options available:

1. Surgery: Surgery is the most common treatment for colon cancer at all stages, which involves removing the tumor during an operation. The nature of the cancer determines the type of surgery. It can be local excision for a limited tumor or extensive resection for a cancer that has spread.

• Local excision: If the cancer is discovered relatively early, your doctor can remove it without penetrating the abdominal wall. Instead, the surgeon could insert a tube with a cutting instrument into the rectum and colon to remove the malignancy.
• Resection of the colon with anastomosis: If the malignancy is more advanced, your doctor will perform a partial colectomy. The physician could then carry out anastomosis which is sewing the healthy parts of the colon together.
• Resection of the colon with colostomy: A hole is created outside the body to allow waste to flow through if the doctor cannot stitch the two ends of the colon back together.

2. Radiofrequency ablation: Radiofrequency ablation (RFA) is a minimally invasive medical procedure gaining prominence in treating colorectal carcinoma, particularly for certain cases of liver metastases originating from colorectal cancer. It employs high-frequency electrical currents to generate heat, effectively “cooking” and destroying cancerous tissue. RFA can be used alone or with other treatment modalities, such as surgical resection, chemotherapy, or targeted therapies.

3. Chemotherapy: Chemotherapy is a systemic treatment strategy commonly employed in colorectal carcinoma. It utilizes drugs to target and destroy cancer cells throughout the body, making it particularly useful for advanced-stage colorectal cancer or when cancer has spread to other organs. Chemotherapy may be administered before surgery to reduce the size of tumors, post-surgery to eliminate any remaining cancer cells, or in combination with other therapies such as radiation or targeted therapies. Common chemotherapy drugs for colorectal carcinoma include 5-fluorouracil (5-FU), oxaliplatin, and irinotecan. Although chemotherapy can effectively slow cancer growth and extend survival, it may also produce side effects, such as fatigue, nausea, and lowered blood cell counts, which medical professionals closely monitor and manage.

4. Radiation therapy: High-energy X-rays or other forms of radiation are used in radiation therapy, which helps to kill or stop cancer cells’ growth. External radiation therapy uses a device outside the body to direct radiation at the cancerous region. Internal radiation therapy uses catheters, seeds, wires, or needles with radioactive materials sealed inside that are inserted into or close to the malignancy.

5. Targeted therapy: Targeted therapy is a form of medical care that isolates and destroys particular cancer cells using medicines or other substances. Compared to chemotherapy and radiation therapy, targeted therapies often don’t kill healthy cells as much.

6. Immunotherapy: Immunotherapy is a cancer treatment that activates the patient’s immune system. The body’s natural defenses against cancer are boosted, directed, or restored using substances produced by the body or in a lab. Biologic therapy is a kind of treatment for cancer.

Tips To Prevent Colon Cancer

• Consume a fiber-rich diet
• Limit consumption of alcohol
• Quit smoking
• Maintain a healthy body weight
• Get regular colorectal screening

Questions For Your Doctor

1. What stage is my colon cancer, and what does that mean for my treatment options?
2. What are the potential side effects of colon cancer treatment?
3. How do you monitor for post-treatment colon cancer recurrence?
4. How will my treatment impact my long-term health and quality of life?
5. How often will I need to come in for check-ups and testing during and after treatment?
6. Will I be able to work during my treatment and recovery?
7. Can the treatment affect my daily life?
8. Does the cancer get inherited by my children?

References

1. https://www.cdc.gov/cancer/colorectal/basic_info/prevention.
2. https://www.cancer.org/cancer/colon-rectal-cancer/causes-risks-prevention/risk-factors.html