What is Colon and Colon Cancer
Colon is the part of the body called the large intestine. It is present in the abdomen and connects to the small intestine at one end and rectum at the other. It can be divided into the caecum, ascending colon, transverse colon, descending colon and sigmoid colon. The sigmoid colon continues as the rectum.
The food that is eaten is digested in the stomach and intestine. All the nutrients are absorbed in the small intestine and the digested food that is not required passes into the colon. Water that is present in this digested food is absorbed in the colon and the remaining waste passes into the rectum where it is stored before being excreted.
Cancer that starts in the colon is called as colon cancer. By far the commonest type of colon cancer is an adenocarcinoma. This type of cancer starts in the innermost lining of the colon called the mucosal layer. Colon cancer can spread from the mucosal layer into other layers of the colon and then to the outside of the colon. This type of spread is called direct spread. It can also spread through the lymphatic channels into the lymph nodes around the colon and to other parts of the body. The cancer also spreads through the blood stream to other parts of the body such as liver and lungs.
According to Globocan data 2018, there were 27605 new colon cancers diagnosed in India in 2018, making up 2.4% of all cancers.
Risk Factors for colon cancer
Symptoms of Colon cancer
Colon Cancer can present with a variety of symptoms and these are listed below
Staging of Colon Cancer
The stage of a cancer is a term used to describe the size and location of the cancer in the body.
Knowing the stage of the cancer helps the doctors to decide on the most appropriate treatment. Colon cancer is staged based on the TNM staging system or the number system.
Staging with either system is based on the extent of the tumour in the colon, the spread of the cancer in the colon and into the lymph nodes and spread of cancer into other parts of the body.
TNM stands for tumour, node and metastases. T stands for tumour and in colon cancer represents depth of spread into the wall of the colon. N stands for nodes and spread of cancer into lymph nodes around the colon. M stands for metastases and spread of cancer to distant areas in the body.
Treatment of Colon Cancer
Surgical treatment of Colon Cancer
Treatment of Colon cancer involves use of surgery, chemotherapy and sometimes radiotherapy.
Chemotherapy for colon cancer
Chemotherapy is an important component of treatment for Colon cancer. Chemotherapy is given in a number of settings in this condition.