Colorectal cancer is formed either in the colon or the rectum. These cancers are also named as colon cancer or rectum cancer, depending on the particular place where it has started. Both colon and rectum cancer are often grouped together and named as colorectal cancer because they have many common features. Cancer begins when cells of the body in a particular organ grows beyond control. Every day cells in our body destroyed and replaced by new one with a perfect copy of the old cell to perform the same function. The problem arises when the new cell divides independently and set-asides the checks and balances mechanism prevailing in the body to control the normal cell growth. That particular cell itself can start multiplication in an uncontrolled manner, which is completely different from a normal cell. This type of cell can either be non-cancerous or malignant. This abnormal growth may be observed in any part of the body. If it is seen in colon or rectum it will be said colorectal cancer.
What is colorectal cancer and how it begins?
Colorectal cancer begins when the normal process of substitution of colon lining cell goes amiss. The consequence of the growth of the incorrect cells, polyps appear on the wall of the colon. If these polyps are malignant, these start to grow in two ways. First, the cancer cells can grow locally and even spread over the wall of the intestine and capture adjoining structure to make the mass called a primary tumor. This extension causes perforation or blockage of the colon or nearby structures. Second, over the time as cancer grows, it can spread by a process called metastasis.Cancer cells enter the bloodstream or lymphatic system and spread to a distant organ such as abdominal cavity, liver, lung etc.
What are the causes of colorectal cancer?
Factors that cause colorectal cancer are as follows:
What are the symptoms of colorectal cancer?
Symptoms of colorectal cancer are nonspecific and numerous. This may include weakness, fatigue, shortness of breath, diarrhea or constipation, narrow stools, change in bowel habit, bright blood in stool, abdominal pains and many more. Colorectal cancer develops for several years without showing any symptom.
What are treatments for colorectal cancer?
Surgery is the common option for the treatment of colorectal cancer. During surgery, the tumor along with a margin of the healthy intestine and adjoining lymph nodes are removed. To lower the risk recurrence of cancer, oncologists recommend adjuvant chemotherapy. There are options for the adjuvant chemotherapy drug to give it orally or direct into the veins decided by the oncologist. Occasionally, radiation therapy is also used as palliative treatment to relieve the pain from a recurrence of metastatic colorectal cancer. With latest advances in surgical techniques and chemotherapy, the cure rates of colorectal cancer are very encouraging.
Authored By Dr G Parthasarathy - Surgical Gastroenterologist, Hyderabad