What Are The Causes Of Colorectal Cancer?

Colon And Rectal Cancers In Singapore

Colorectal cancer comprises cancers of the colon and of the rectum. It is one of the ten most frequently occurring cancers for men and women for the period 2015-2019 according to the Singapore Cancer Registry Annual Report. In addition, it is a leading cause of death in cancer patients. Although there is uncertainty about what causes colorectal cancer, medical science knows how it develops and becomes evident in the body.

Colorectal Cancer Causes

Colorectal cancer develops when irregular cell growth occurs in the colon or rectum. These two are the resting points of the digestive system.

The colon is a part of the large intestine connecting to the anus. The large intestine measures about 5ft and provides ample room for cellular modification and growth. A majority of colon and rectum cancers originate in the mucus-producing cells.

Cells typically develop, divide, and die in a systematic manner. However, cells that continue to grow and divide unchecked and do not die at the expected time in their life cycle become a cancerous.

The term “polyp” refers to an abnormal growth that occurs within the colon. The majority of polyps are benign, but a small percentage of them are cancerous. Those with noncancerous polyps inside the dietary tracts can have a higher risk of developing colon cancer. These polyps can further increase and grow on the walls of the large intestine. Later, it can form malignant tumours and spread to other surrounding organs through lymph systems and blood.

Metastasis is the process by which cancer cells spread from their original site of origin into healthy tissues all over the body. As a result, the illness becomes more severe and less curable.

Risk Factors For Colorectal Cancer

Despite uncertainty about the precise reasons behind colon cancer, many experts agree that certain risk factors and those with a family history have a higher chance of developing this disease. For example, people over 50 are at a higher risk, according to the Singapore Cancer Society.

Similarly, changes in DNA caused by uncontrolled cell growth can lead to colon or rectal cancer. Colon cancers caused by certain hereditary disorders account for 5–10 percent of all cases.

Colorectal polyps that are large, numerous, or include irregular but non-malignant cells increase a person’s risk of colon cancer. Patients who have had colorectal cancer in the past are also at a greater risk of developing the disease again.

Colorectal cancer is more likely to occur in people with a genetic predisposition. Polyposis syndromes such as familial adenomatous and Lynch syndromes are among them (FAP). In addition, researchers are investigating if additional gene variants, such as BRCA1 and BRCA2 mutations related to breast cancer, may also enhance the potential risk of colon cancer.

Obesity is associated with an increased risk of colon cancer, especially for men. However, people can avoid excess weight gain and lower the risk of colon cancer by adopting an active lifestyle and exercise routine.

Medical conditions like Crohn’s disease or ulcerative colitis may also contribute to cancerous cell growth. People with a history (more than 10 years) of any of these diseases are prone to colon cancer. Around ten years following the onset of the first symptoms, people with one of these disorders would often undergo periodic examinations to detect any signs of colon cancer at an early stage. Doctors can recommend colonoscopy to find polyps in the colon before sending the sample for biopsy, which looks for noncancerous and cancerous cell growth.

Heavy smoking or drinking habits increase cancer risk, including colorectal cancer.

Knowing about the possible symptoms and regular screening can help detect colon cancer early and provide timely medical attention.