Colon Cancer

What are the parts of the colon?

Why does colon cancer occur?

Colon cancer is among the more common cancers. Though the cause cannot be pinpointed to one factor there are many risk factors

• A few people have a hereditary risk of developing colon cancer. There are many hereditary conditions like familial adenomatous polyposis coli and lynch syndrome which increase risk of colon cancer.
• Having certain types of polyps in the large intestine increases the risk of colon cancer
• Smoking is known to increase the risk
• Consumption of diet poor in fibers and high amount of red meat is known to increase the risk.

What are the symptoms of colon cancer?

• Most people with colon cancer notice a change in their bowel habits which may alter between diarrhea and constipation.
• Few patients may notice blood in their stools
• Some patients may experience abdominal cramps and bloating
• Few patients may be asymptomatic. Sometimes colon cancer is detected during evaluation for anemia
• Few patients present with features of intestinal obstruction like abdominal distension and vomiting Patients may directly present with metastases in the liver and colon cancer may be detected later on evaluation.

How is colon cancer diagnosed?

Whenever any of the above mentioned symptoms are present a colonoscopy is done. During colonoscopy a lighted tube with camera is passed up the anal canal and the entire colon upto the caecum is visualized.

If any suspicious lesion is found it is biopsied. Following diagnosis other investigations like CT scan or PET CT is done

What are the treatments available for colon cancer?

The normally used treatments for colon cancer are

• Surgery
• Chemotherapy and targeted therapy
• Radiation is rarely used for colon cancer

What type of surgery is done for colon cancer?

Surgery is most important treatment for colon cancer which has not spread to far off organs Surgery involves removing not just the tumour but a segment of the colon with common blood supply. This procedure is known as radical hemicolectomy.

Based on which side the surgery is done, there can be right and left radical hemicolectomy When the sigmoid colon is affected, the procedure is similar and is known as radical sigmoid colectomy.

Sometimes if the ends of the bowel are not healthy to be joined or if the tumour is obstructed and cannot be removed, a loop of intestine proximal to the tumour will have to brought out to the abdominal wall. This is known as colostomy.

Can the surgery be done using key holes?

Both laparoscopic and robotic method are used frequently for surgical treatment of colon cancer when suitable. This helps reducing the pain, avoids wound complications and helps in early recovery

What are the risks associated with colon cancer surgery?

Colon cancer is generally safe when performed by experienced hands. However sometimes complications can occur. The main complication is anastomotic leakage where there is leakage of the intestinal contents from the new joint made. This may necessitate the patient to be taken back to the operating room. Apart from this the new joint may become narrow producing symptoms of intestinal obstruction.

What are the expected outcomes of colon cancer?

Chances of cure and long-term survival are good in early-stage colon cancer. Cure is achievable in certain cases even when the cancer has spread to the liver.

In metastatic cases which are not suitable chemotherapy is used to prolong life and reduce complications