Understanding colorectal cancer: symptoms, risks and prevention

Just days ago, the family of singer and songwriter Danny K’s wife, Lisa Koppel revealed that she had passed away. 

Danny K, real name Daniel Koppel, later took to social media to reveal the cause of Lisa’s death. 

“Lisa was diagnosed with colon cancer in November 2023. From that moment, she fought with extraordinary strength and determination. Together with our family, we searched for hope in South Africa and around the world, pursuing every treatment and every opportunity available to us. Tragically, despite everything, we could not save her,” he shared on Instagram. 

What is colorectal cancer?

Colorectal or colon cancer develops in the colon or rectum and can take years to progress from abnormal cells to cancer. While many people have no symptoms in the early stages, recognising potential warning signs and understanding risk factors can help support early detection and prevention.

Colorectal cancer, also known as bowel cancer, begins when the normal process of replacing cells lining the colon and rectum goes awry.

Errors during cell division can sometimes escape the body’s normal mechanisms for correcting them. The abnormal cells may then multiply without the usual controls on growth, forming growths known as polyps.

Many polyps are precancerous and develop slowly over several years without spreading. As they grow, further genetic changes can cause the cells to become increasingly abnormal.

When a precancerous polyp invades deeper layers of the large intestine, it becomes cancerous. In most cases, this is a slow process that takes at least eight to 10 years to progress from the earliest abnormal cells to established cancer.

Symptoms of colorectal cancer

Some people with colorectal cancer have no symptoms in the early stages. When symptoms do occur, they can vary depending on the size and location of the cancer.

Possible signs include:

• Changes in bowel habits, including diarrhoea, constipation or changes in stool consistency.

• Rectal bleeding or blood in the stool.

• Persistent abdominal discomfort, including cramps, gas or pain.

• A feeling that the bowel has not emptied completely.

• Weakness or fatigue.

• Unexplained weight loss.

Who is at greater risk?

The risk of colorectal cancer increases with age, with most cases occurring in people aged 50 and older.

Other risk factors include previous radiation therapy for cervical cancer, a personal history of colorectal cancer or polyps, and chronic inflammatory bowel diseases such as ulcerative colitis and Crohn’s disease.

People with a family history of colorectal cancer or polyps may also face an increased risk, particularly when a first-degree relative developed the condition before the age of 60.

Inherited conditions such as familial adenomatous polyposis and Lynch syndrome are also associated with increased risk.

Lifestyle factors

Several lifestyle factors may contribute to the risk of developing colorectal cancer. These include physical inactivity, being overweight or obese, a low intake of fruit and vegetables, and diets that are low in fibre and high in fat and sugar.

High consumption of red and processed meat, alcohol and tobacco are also associated with increased risk.

Processed meats, including sausages, luncheon meats, ham and biltong, can increase the risk of colorectal cancer. Cooking meat at very high temperatures, such as through frying, broiling or grilling, can also create chemicals associated with increased cancer risk.

Reducing the risk

Lifestyle changes may help lower the risk of colorectal cancer.

A diet rich in fibre, particularly from fruit, vegetables and whole grains, is associated with a lower risk. Eating more fruit and vegetables may also be beneficial.

The source material also highlights fish rich in Omega-3 and calcium-rich diets as potentially protective, while limiting red and processed meat is recommended.

Avoiding alcohol and tobacco can further reduce risk. Regular physical activity and maintaining a healthy body weight are also important, as physical inactivity and obesity are associated with a higher risk of colorectal cancer.

Screening and early detection

People with familial risk factors may require screening before the age of 50 or more frequent testing.

Genetic testing may help identify people with suspected inherited colorectal cancer syndromes who could benefit from closer monitoring. Colonoscopy is more commonly used when screening people considered to be at high risk.

A faecal occult blood test can detect microscopic blood in stool. Blood in the stool may be associated with a growth, inflammation or bleeding in the digestive system.

Understanding personal risk factors and discussing appropriate screening with a healthcare provider can help with the early detection of colorectal cancer.

IOL