Colon Cancer

Overview

Colon cancer is a type of cancer that affects the colon or rectum. It can develop slowly and may not show symptoms in the early stages. Common types include adenocarcinoma and carcinoid tumours. Risk factors of this disease include age, family history, and lifestyle. Prompt diagnosis and timely treatment of these conditions minimise the complications. The risk of colon cancer can be prevented by incorporating healthy habits in daily life and opting for early screening.

What is Colon Cancer?

Colon cancer, or colorectal cancer, is the growth of abnormal cells that are found in the colon, the body's longest part of the largest intestine. The division of cells forms as a polyp (often non-cancerous) in the initial stages, which gradually becomes cancerous and spreads to vital organs, including the liver and lungs. One may not experience any symptoms in the early stages, however, they must get screened early for early detection.

Types of Colon Cancer

The different types of colon cancer are listed below:

Adenocarcinoma

These are cancerous cells that are found in the inner surface of the colon or the glands that produce mucus in the colon and rectum. The cancerous cells may grow slowly and turn aggressive, spreading to other body parts. It is the most common colorectal cancer type, and symptoms include blood in stool, abdominal pain, change in bowel habits and weight loss.

Carcinoid Tumours

This is a slow-growing neuroendocrine tumours that can develop in the gastrointestinal tract or the lungs. They may result in excess hormone production, leading to symptoms like diarrhoea, flushing, wheezing, and heart palpitations.

Gastrointestinal Stromal Tumours

It is a type of cancer that starts in the cells of the gastrointestinal tract. These cancerous cells are more commonly found in the small intestine and stomach lining. Individuals may experience a mass in the abdomen, feeling full quickly when eating and abdominal discomfort.

Lymphoma

Here, cancerous cells grow and multiply in the lymph nodes in the colon. This type of colon cancer results in the immune system attacking its healthy cells, which then grow into malignant cells. The cancer may spread across the spleen, tonsils, bone marrow and thymus.

Symptoms of Colon Cancer

One may not experience the symptoms of colon cancer in the early stages. However, they commonly include blood in the stool, changes in stool colour, constipation, diarrhoea, bleeding from the rectum, abdominal pain, excessive fatigue, unexplained weight loss, narrowed stool and the feeling that the bowel is not empty.

Causes of Colon Cancer

The exact causes of colon cancer are unknown. However, researchers suggest that it can be either inherited or acquired. Genetic conditions, including familial adenomatous polyposis (FAP), cystic fibrosis, lynch syndrome, or Gardner's syndrome, may cause abnormal cells to grow in the colony lining, forming polyps. While polyps are usually benign, with time they can become cancerous if left untreated.

Risk Factors of Colon Cancer

Risk factors, including age, family history of the disease or other genetic conditions, ethnicity, and lifestyle choices such as smoking, alcohol intake, obesity, unhealthy diet and being physically inactive increase the risk of developing cancer.

Diagnosis of Colon Cancer

Colon cancer diagnosis and tests include complete blood count (CBC), biopsy, comprehensive metabolic panel (CMP), colonoscopy, faecal immunochemical test (FIT), X-rays, ultrasound, CT scan, faecal DNA test and flexible sigmoidoscopy. Other tests may also include an MRI scan, virtual colonoscopy, carcinoembryonic antigen (CEA) assay, and PET scan.

The following are the different stages of colon cancer:

• Stage 0: Abnormal cells that occur in the inner colon lining only, and also known as carcinoma in situ
• Stage 1: Malignant cells penetrate the mucosa of the colony and grow into the muscle layer
• Stage 2: Cancerous cells spread to the colony walls or nearby tissues, without affecting the lymph nodes
• Stage 3: The cancer moves to the lymph nodes only
• Stage 4: Cancer spreads to other organs including the lungs or livers

Treatment for Colon Cancer

Colon cancer treatment and medications depend on its stage, location, and the overall health of the patient. Usually, a professional may recommend minimally invasive surgeries to remove small colon cancer, which includes polypectomy, laparoscopic surgery and endoscopic mucosal resection.

Advanced stage colon cancer may require surgery options including lymph node removal and partial colectomy. Other treatment plans include radiation therapy, chemotherapy, targeted therapy, ablation therapy and immunotherapy.

Prevention of Colon Cancer

There is no guarantee for prevention of colon cancer. However, getting early screening can help to understand if abnormal cells are turning into cancer. Besides one should maintain an ideal weight in proportion to their height, remain physically active, avoid smoking and limit alcohol intake to control the risk factors of colon cancer. People should also consume a healthy diet which is rich in vitamin D, magnesium, calcium, lean proteins and fibre to minimise the chances of occurrence of this condition.

Myths and Facts Related to Colon Cancer

Learn about the myths and facts about colon cancer through the following points:

Myth 1: Colon Cancer affects only older people
Fact: While colon cancer is more common in older people over 50, it can occur at any age. In your individuals, it can start as polyps, non-cancerous cells, which can, over time, turn into colon cancer.

Myth 2: One can see early symptoms if they have colon cancer
Fact: Many individuals often do not experience any symptoms in the early stages, which makes it necessary for them to get regularly screened for early detection.

Myth 3: Colonoscopy is the only way to detect colon cancer
Fact: Colonoscopies are the fold standard. However, other screening methods such as stool tests (FIT, FOBT) and CT scans also help detect colon cancer early.

Myth 4: Eating healthy and exercising reduces the risk of developing colon cancer
Fact: Leading a healthy lifestyle reduces the risk but does not eliminate it. One can develop colon cancer because of factors such as genetics and age.