Silent Enemy: Colorectal Cancer Unveiled

Colorectal (Colon) cancer accounts for about10% of all cancers, making it the third most common type of cancer globally. It’s also the second leading cause of cancer-related death worldwide. 

According to theWorld Health Organisation report, there were over 1.9 million new colon cancer cases and over 93,000 deaths in 2020. The report also estimates that there will be about 3.2 million new colorectal cancer cases and 1.6 million deaths annually by 2040. In other words, we expect an increase of 63% in colon cancer cases and 73% in deaths. 

All these facts show how colorectal cancer is a serious health concern. So, in this article, we’ll discuss what causes colorectal cancer, what it entails, and what to do if you have it! 

How Does Colorectal Cancer Develop?

Colorectal cancer starts as tissue growth along the inner lining of the colon or rectum, calledpolyps.Most colon polyps are harmless, but over time, some can develop into colon cancer.

Thetype of polypsdetermines whether they become cancerous. The different types of polyps include:

• Adenomas(Adenomatous polyps): Also referred to as a precancerous condition, this type of polyps can change into cancer. These polyps develop on the mucous membrane lining of the colon.
• Inflammatory polypsand Hyperplastic polyps: These polyps develop as a result of a reaction to chronic colon inflammation. They are the most common type of polyps and carry a risk of growing into cancer. So, people with large hyperplastic polyps often require colon cancer screening alongside colonoscopy.
• Traditional Serrated Adenomas(TSA) andSessile Serrated Polyps(SSP): They are more likely to develop into colorectal cancer and are treated like adenomatous polyps.

Generally, polyps that are large and contain abnormal cells (i.e.dysplasia) are likely to lead to colorectal cancer. If the cancer cells grow into lymph nodes or blood vessels they may end up spreading to other parts of the body. 

Causes of Colorectal Cancer

Colorectal cancer can be the result ofmedical conditions or lifestyle choices.

1. Medical Conditions

• Many colon polyps: Having too manyserrated polyps or adenomas is found to increase the risk ofcolorectal cancer. 
• Inflammatory bowel disease: People suffering from conditions such as Crohn’s colitis and ulcerative colitis, which irritate the colon lining, are at a higher risk of developingcolorectal cancer. 
• Family history of Colorectal Cancer:If you hail from a family with a history ofcolorectal cancer, then you are at risk of developing colorectal cancer. You can also inherit conditions like familial adenomatous polyposis and Lynch syndrome that may develop intocolon cancer.
• Diabetes: If you have insulin resistance or suffer from diabetes, you are at risk of developing colorectal cancer.

2. Lifestyle Conditions

• Being Obese:Foods that have high fats and calories are likely to increase yourweight and put you at risk of developing colorectal cancer. Obese people have an18-32% risk of developing colorectal cancer compared to others.
• Smoking: Tobacco products and e-cigarettes will increase your chances of getting colorectal cancer.
• Physical Inactivity: If you do not exercise, you increase your chances of developing colon cancer.
• Alcohol Intake: Alcohol consumption increases the risk of colorectal cancer by at least1.2 to 2.5-fold.
• Low-fiber diet:Low fiber intake and increased processed and red meat intake are linked with rectal and colon cancers.

3. Other Causes of Colorectal Cancer

• Old Age: Colorectal cancer is prevalent in people aged50 years and above. Polyps are more likely when you grow older.
• Race:Black people have a higher chance of developing colorectal cancer.
• Radiation therapy: Theradiation therapy directed at the abdomen is likely to increase the chances of developing colorectal cancer.

What are the First Signs of Colon Cancer?

At the onset of colon cancer, you may not experience any signs and symptoms. Besides, your symptoms will likely be mistaken for other diseases. 

Below are the commonsigns and symptoms of colorectal cancer:

• Changes in appetite
• Rectal bleeding
• Abdominal pain and cramping
• Abnormal bowel habits like constipation, narrowing of stool, and diarrhea
• Bloated stomach
• Excessive vomiting
• Excessive fatigue and shortness of breath due to iron deficiency
• Sudden weight loss 
• Discomfort when sitting down

Diagnosis

Colorectal cancer does not reveal any signs and symptoms during its early stages. That is whyscreening tests come in handy to reveal any precancerous polyps that cause colorectal cancer.Additional tests are needed to diagnose this type of cancer.

1. Screening Tests

According to theU.S Preventive Service Task Force, adults aged between 45 years and 75 years should regularly undergo screening tests for colorectal (colon) cancer. Screening helps to identify precancerous polyps that can potentially cause colorectal cancer. 

Thescreening testsinclude:

• Colonoscopy is the most common colorectal screening test. It involves a long, thin, flexible tube being inserted into the rectum and the entire length of the colon, which searches for potential precancerous polyps and facilitates their removal. 
• Computed tomography (CT) Colonography (Virtual Colonoscopy): It entails using computers and X-rays to capture images of the rectum and colon for analysis to detect tumors, ulcers, and polyps.
• Flexible sigmoidoscopyis a procedure that requires a sigmoidoscope, a flexible, narrow tube fitted with a camera.  The device is inserted through the rectum and visualizes the left or descending colon.
• Fecal Immunochemical test (FIT) involves using antibodies to test stool samples for blood the naked eye cannot see. It should be done once a year.
• FIT-DNA test: This test combines the FIT with a test for detecting genetic mutations in the stool. It should be carried out once every three years.
• The guaiac-based Fecal Occult Blood test (gFOBT) relies on a plant-based chemical called Guaiac, which turns blue when exposed to blood.  It is used to detectinternal bleeding. The bleeding can indicate polyps or colon cancer.

2. Diagnosis Tests

The choice of tests for diagnosing colorectal cancer is dependent on a wide variety of factors including age, family, and medical history.

Below are some of thetestsused in diagnosing colorectal cancer: 

• Biopsy: It is a test that provides a definite diagnosis of colorectal cancer. The test involves examining a small tissue under a microscope to determine if the cells of the tissue are cancerous.
• Biomarker testing of the tumor: A sample of the tumor is tested for proteins and specific genes. The doctor will take a sample of the tissue in the area affected by colorectal cancer, then stain it or analyze it to check for microsatellite instability. It is used in the search for Lynch syndrome and in determining whether immunotherapy is a viable treatment option for cancer. 

How is Colon Cancer Treated? 

Colon cancer can be treated throughsurgery andadjuvant therapy. However, the most common treatment plan for colon cancer is surgery.

a) Procedures and Surgeriesfor Colon Cancer

• Radiofrequency ablation: The procedure entails using heat to destroy cancerous cells.
• Colon resection (Partial colectomy): The surgeon removes the tumor alongside some surrounding tissue and then reconnects the healthy sections of the colon using anastomosis.
• Polypectomy: The surgeon gets rid of the cancerous growths or polyps.
• Surgical resection with Colostomy: It is a type of surgery that entails removing the part of the colon with a tumor. A new opening known as a stoma is created to act as the new passage for gas and solid stool. That is because, after surgery, they cannot connect the sections of the healthy colon.

Surgery is the best option for the early stages of colon cancer when the tumor has not spread to other body parts. 

b) Adjuvant Therapies

Therapy as a treatment plan for colon cancer can be done before surgery or after. The different types of therapies for colon cancer include:

• Targeted Therapy: This type oftherapy is focused on the tissues, proteins, and genes that promote the growth and spread of colon cancer cells. It entails usingantibodies created in the lab that attach to cancer cells. This helps the immune system to find these cells and act against them. 
• Chemotherapy:Chemotherapy drugs destroy rapidly dividing cancer cells by interfering with their nuclear material. 

Can Lifestyle Changes Prevent Colorectal Cancer?

Lifestyle changes can reduce the risk of developing colorectal cancer. So, 

• Avoid Smoking: Stay away from any tobacco products. 
• Engage in Physical Activities: Exercise for at least 30 minutes daily. A medical practitioner can recommend a perfect training program for you. Exercising allows you to shed excessive weight, among many other benefits.
• Eat a Healthy Diet:The right diet for preventing colorectal cancer should contain vegetables fruits, and fiber. Avoid foods that are rich in fats and calories. Also, reduce your consumption of red meat and processed foods.
• Maintain Healthy Weight:Exercising and eating a healthy diet will enable you to maintain the right body weight. You can lose excessive weight by eating foods that have fewer calories. This will help you avoid the risk of developing obesity, which is a risk factor for colorectal cancer.
• Reduce Alcohol Consumption:You can quit drinking alcohol or reduce your alcohol intake.

Is a Plant-based Diet Good for Colorectal Cancer?

According to astudy by the National Institutes of Health, a plant-based diet of whole grains, legumes, nuts, and vegetables reduces the risk of developing colorectal cancer. 

Vegetables, whole grains, and fruits are rich in fiber, which helps minimize the risk of colorectal cancer. The good bacteria in the colon convert the fiber into short fatty acids which minimizes the chances of cells in the colon becoming cancerous. According to astudy, people who add whole grains to their diet are at a lower risk of suffering from colorectal cancer.

Switching to aMediterranean diet is a perfect way of having a plant-based diet. 

This diet consists of vegetables and fresh fruits, which minimize the risk of colorectal cancer by about 43%. According to the U.S. Department of Agriculture’s Dietary Guidelines Advisory Committee, the Mediterranean diet is a healthy eating approach that addresses nutrient needs while minimizing the risk of various chronic diseases, including cancers.

Conclusion

Colorectal cancer is characterized by uncontrolled growth of cells in the colon and rectum. The early stages of colorectal cancer may not reveal any signs or symptoms. So, screening and diagnostic testing are vital to pick up the presence of precancerous lesions. If these lesions are confirmed to be cancerous, then surgery and adjuvant therapy are used to treat them. 

Your lifestyle can also impact the likelihood of colorectal cancer. If you lead a sedentary lifestyle and consume a mainly processed diet, then you are at higher risk of having this type of cancer. 

To reduce the risk of colorectal cancer, it would be ideal to increase your physical activities, quit smoking, stop excessive consumption of alcohol, and stick to a plant-based diet that is rich in fiber.