In India, colorectal cancer, which first appears in the colon or the rectum, is the sixth most prevalent cancer to cause mortality. It generally affects older persons and happens when colonic cells become uncontrolled (above 45 years). The polyps that originate inside the colon are typically the precursors to this type of cancer. Over time, these polyps develop into cancerous cells. A tumour forms when the DNA of the colon's healthy cells mutates and the cells build up together. These cancer cells expand over time, invading neighbouring healthy tissue and wreaking havoc.

Although there is no known cause of colorectal cancer, those without a family history of the disease account for the majority of cases. However, one in three individuals with the illness also has a parent, brother, or kid who has experienced colorectal cancer.

This increases the risk for those who have had colorectal cancer in the past. The causes of the increased risk are not always evident, although the risk is higher if more than one parent, sibling, or child is affected by cancer or if their relative had cancer when they were younger than 50. You should talk to your doctor and ask about the necessity to begin screening before the age of 45 if you also have family members with adenomatous polyps or a history of them. If you have had colorectal cancer, you should tell your close family so they can begin screening

Colorectal cancer presents several symptoms and risk factors which can help in identifying it early. These include

Symptoms

Constant changes in bowel habits diarrhoea or constipation and modifications in stool

Blood or rectal bleeding stool

Persistent discomfort in the abdomen such as cramps, gas or pain

Fatigue or weight loss

The symptoms of Colorectal cancer vary from patient to patient in terms of size, and location in the large intestine. Several people with colon cancer do not experience any symptoms in the early stages of the disease.

Risk Factors

Old age - While colon cancer can be diagnosed at any age but it is mostly found in people above the age of 50 years. There is no specific cause behind the diagnosis as the number is also increasing among young people.

Personal History - If you have already had colon cancer or non-cancerous polyps then you are at a greater risk of getting colon cancer in future.

Inflammatory intestinal conditions - It includes diseases like Crohn's disease and ulcerative colitis that can increase your risk of colon cancer.

Inherited Syndromes - A very small percentage of colon cancers are caused due to inherited syndromes like Familial Adenomatous Polyposis (FAP), and Lynch syndrome, which is also known as Hereditary Nonpolyposis Colorectal Cancer (HNPCC).

Family History - The risk of Colorectal cancer increases if you have a blood relative who has had the disease. If more than one family member has colon cancer then the risk is even greater.

Sedentary Lifestyle - People who are inactive or adopt a high-fat or low-fibre diet are at an increased risk of colon cancer. Alcohol consumption and heavy smoking put you at higher risk. Following a healthy lifestyle and getting regular physical activity can reduce your risk.

Type 2 Diabetes - Patients with type 2 diabetes (non-insulin-dependent) have an increased risk of colorectal cancer.

Obesity - People who are obese are at increased risk and have less favourable outcomes compared to people with normal weight.

Radiation therapy - This therapy when directed towards the abdomen to treat previous cancers increases the risk of colon cancer

How can you prevent yourself from colon cancer?

There are several precautionary measures that you can adopt to prevent yourself from colon cancer -

Screening - Colon cancer screening through traditional colonoscopy every 10 years after the age of 45 is recommended before any signs or symptoms may develop. Doctors also include several other tests that include -

Colonoscopy - It is a type of screening where a colonoscope is used to gain images of the colon and rectum. This method is considered the "gold standard" in colon cancer screening because of its accuracy and the ability of your doctor to remove the growths at the same time.

Virtual/CT colonoscopy - In this method the doctors use computed tomography (CT) scans once the colon is slightly inflated to provide clearer images

Flexible sigmoidoscopy - This uses a light and camera lens or a sigmoidoscope to view the colon

Fecal occult blood test (FOBT) - This screening method uses a light and camera lens or a sigmoidoscope to examine the colon. With this test, the doctors can find microscopic traces of blood that may not be visible during a normal bowel movement at home.

DNA stool test - This helps in analyzing a stool sample for any genetic changes that can indicate colorectal cancer.

Lifestyle changes - Moderating your alcohol consumption, curbing smoking, maintaining a healthy weight and regular exercise are some preventive measures through which you can reduce your risk of colon cancer.

(Dr. Vijay Agarwal, Lead & Sr. Consultant - Medical Oncology & Haematology)