Colorectal cancer (CRC) is common cancer worldwide. In 2015, 771,000 people died due to colorectal cancer globally, making this disease the fourth most common cause of cancer-related death worldwide after lung, liver and stomach cancer. Colorectal cancer is the third most commonly diagnosed cancer in men and the second in women.
Although the number of cases of colorectal cancer is far less than the west, the incidence is rising as it is the fifth leading cause of cancer-related deaths in the country. Being aware of colorectal cancer can not only help in the early diagnosis and timely treatment but can also help to prevent it. Dr. Ajay Kumar, Chairman – Fortis Escorts Liver and Digestive Diseases Institute elaborates on the causes and risk factors of this killer disease.
What Is Colorectal Cancer?
Colorectal cancer begins as a tumor or abnormal tissue growth on the inner lining of the rectum or colon. This abnormal growth, which is clinically termed a polyp, can eventually become cancerous and form a tumor on the wall of the rectum or colon. Around 95% of the cancers that begin in the colorectal region are classified as adenocarcinomas (a type of cancer which arise from the glands). These type of cancers begin in the mucus-making glands which line the colon and rectum.
Colorectal cancers are known as slow-developing cancers are it might take many years for the formation of an adenoma (polyp) and its development into cancer. This is the reason that if adenomatous polyps are picked up early and removed under medical guidance, then colon cancer can be prevented.
What Are The Main Causes And Risk Factors For Colorectal Cancer?
There are certain factors which might increase your risk of colon cancer. These include:
Genes: Any mutation in the genetic material of the cells that line the colon can cause colon cancer. These genetic changes are inherited from family members, which increases the risk significantly. This is why if you have a family history of colorectal cancer, it is advised to get screened for cancer. The most common form of hereditary colon cancer is ‘Hereditary non-polyposis colorectal cancer syndrome’ and ‘familial adenomatous polyposis.’
Alcohol and smoking: Excessive consumption of alcohol and tobacco can also lead to the ingestion of carcinogenic material which in turn can cause colorectal cancer. A 2011 research study has revealed that as compared to occasional drinkers, people who consume at least 4 drinks per day are at a 52% increased risk for developing this disease. Tobacco smoke has been associated with a twofold to threefold increase in the risk of developing colorectal adenoma and significantly increases the incidence and mortality due to colorectal cancer.
Diet: A sedentary lifestyle which involves little or no exercise along with a diet which is low in fibers, high in red meat, processed meat and calories contribute to the formation of malignant or cancerous polyps.
Age: Studies have reported that the risk of developing colorectal cancer increases with age. Women above the age of 40 years and men above the age of 50 years are more prone to colorectal cancers.
Diseases: There are certain conditions that can increase the risk of colorectal cancer such as high blood levels of insulin and some gastrointestinal diseases. Research suggests that about 1% of all colorectal cancer cases are due to the chronic inflammation associated with ulcerative colitis. Crohn’s disease, which is marked by intestinal inflammation, has also been shown to increase the risk of colorectal cancer.
While there is no way to prevent the occurrence of cancer, the risk associated with it can be lowered by maintaining the weight on the lower side, engaging in physical activity every day and ensuring adequate intake of Vitamin D and calcium. Also, consume more fresh fruits and vegetables instead of foods which are high in calories and limit the intake of red meat, processed meat, alcohol, and tobacco.
(The article is reviewed by Dr. Lalit Kanodia, General Physician)
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