Understanding Colon Cancer: Causes, Symptoms, Diagnosis, and Prevention

Colon cancer is a leading cancer type globally, often developing in the colon or rectum. The World Health Organisation (WHO) reports that colon cancer is the third most frequently diagnosed cancer across the globe, with over 1.9 million new cases recorded in 2020. Although colon cancer can be severe, early diagnosis and lifestyle changes can lower the risk.

What Is Colon Cancer?

Colon cancer, or colorectal cancer, is a form of cancer that forms in the colon (large intestine) or rectum, which are parts of the digestive system). The disease often begins as small, noncancerous growths (polyps) that appear on the inner lining of the colon or rectum. While most polyps remain harmless, some may undergo genetic changes over time, leading to uncontrolled cell growth and cancerous tumours.

What Causes Colon Cancer?

The primary causes of colon cancer are genetic mutations, which cause uncontrolled cell growth in the colon or rectum. These mutations can be-

1. Inherited: Genetic conditions like Lynch syndrome and Familial Adenomatous Polyposis (FAP) increase the likelihood of cancer.

2. Acquired: DNA damage due to inflammation, environmental factors, and lifestyle choices can trigger mutations in colon cells.

Once mutations occur, affected cells divide uncontrollably, forming tumours. Over time, these tumours can invade nearby tissues and spread (metastasize) to other body parts.

What Are the Risk Factors for Colon Cancer? 

Some conditions and lifestyle choices can increase the risk of colon problems. These include:

1. The risk of colon cancer rises after age 50, though cases among younger individuals are becoming more common.
2. A family history of colon cancer or inherited genetic conditions greatly increases the likelihood of developing the disease.
3. Chronic inflammation from conditions like ulcerative colitis and Crohn’s disease can lead to long-term damage to colon cells

What Are the Symptoms of Colon Cancer?

In the early stages, there may not be any noticeable signs of colon cancer. However, as the disease progresses, the following signs may appear:

1. Persistent diarrhoea, constipation, or narrow stools lasting several weeks. Some may also feel like they haven’t fully emptied their bowels.
2. Bright red or dark-coloured blood in the stool, which may indicate bleeding in the colon and should not be ignored.
3. Ongoing cramping, bloating, or lower abdominal pain that requires medical evaluation.
4. Unexplained weight loss, which can signal colon-related health concerns.
5. Persistent fatigue, often due to anaemia from internal bleeding.

How Is Colon Cancer Diagnosed?

Since there may not be any initial signs of colon problems, it can be difficult for doctors to detect them early. However, if someone exhibits symptoms of colon cancer, the following tests are usually recommended:

1. Colonoscopy: A small, flexible, camera-equipped tube is inserted into the rectum to scrutinise the colon for polyps or tumours. Polyps are removed and tested for cancer, if detected.

2. Faecal Occult Blood Test (FOBT) / Faecal Immunochemical Test (FIT): These stool-based tests help detect hidden blood, which may indicate colon cancer or other abnormalities.

3. Stool DNA Test: This test analyses stool samples for genetic markers that may signal cancerous or precancerous changes in the colon.

4. CT Colonography (Virtual Colonoscopy): A non-invasive imaging test that generates 3D images of the colon to identify abnormalities without requiring a traditional colonoscopy.

5. Biopsy: If suspicious growths are found during screening, a small tissue sample is analysed under a microscope to understand if cancer cells are present.

How Can Colon Cancer Be Prevented?

Some risk factors, like genetics, are unavoidable, but lifestyle adjustments can help lessen the risk of colon cancer. These include:

1. Eating a variety of fibre-rich foods and limiting red and processed meats. Adding probiotics can also support gut health.
2. Engaging in at least 30 minutes of moderate exercise on most days to promote overall well-being.
3. Limiting alcohol consumption and quitting smoking can minimise exposure to harmful substances in the body.
4. Maintaining a healthy weight, since excess body fat increases the risk of colon cancer.
5. Undergoing routine screenings starting at age 50 or earlier for those at higher risk. A colonoscopy every 10 years is the gold standard, with stool-based tests as alternatives.

Understanding colon cancer, how to prevent it through lifestyle changes, and regular screenings can significantly lower the risk and improve overall health. Schedule a cancer gene panel for colon with Dr Lal PathLabs, following a medical consultation.

FAQs 

1. What is Stage 4 colon cancer?

In Stage 4, the colon cancer has spread (metastasized) beyond the colon to other distant organs like the liver, lungs, or other tissues. Colon treatment focuses on managing symptoms and slowing disease progression.

2. What are the symptoms of colon problems in females?

Bloating, constipation, diarrhoea, abdominal pain, blood in stool, fatigue, and unexplained weight loss may indicate symptoms of colon problems in females.

3. At what age should colon cancer screenings start?

Routine colon cancer screenings should begin at age 50 for average-risk individuals. However, those with a family history or other risk factors should start earlier, as advised by a doctor.