Colon cancer is the one of the topmost common cancers in Singapore. Your best chances of a cure and increased survival is making the diagnosis at the earliest stage possible. Here we will discuss some of the common surgical treatment strategies.
Endoscopic approach
Colonoscopy is the gold standard in terms of detecting and diagnosing early colon cancers. Unlike a non-invasive scan such as a CT or MRI scan, a colonoscopy allows the doctor the assess the exact location of the tumour and take biopsy samples for a definitive histology. In addition, your doctor can mark the location of the tumour for improved identification during subsequent laparoscopic surgery.
- Polypectomy: a polyp is a tumour growth within the colon that can transform into a cancer over time. Removing the polyps as they first appear is one of the aims of the colonoscopy. As it is not a surgery in the conventional sense, the patient recovers and returns to usual activities soon after the procedure is over. The risks of a polypectomy include bleeding and colonic perforation.
- Endoscopic resection: this is a more complex procedure that involves removing a tumour that is typically a large polyp or an early stage cancer. Not every cancer is suitable for an endoscopic resection and the risks for bleeding and perforation are higher than a polypectomy.
Major colon and rectal surgery
Depending on the location of the tumour, the types of surgery that can be performed are:
- Right hemicolectomy
- Left hemicolectomy
- Subtotal colectomy
- Low anterior resection
- Abdomino-perineal resection
It is important that your surgeon removes all thelymph nodes draining the tumour as this will have a bearing on the staging and prognosis of the cancer.
Each surgery can be done in two different approaches. You and your surgeon will decide which approach is right for you.
- Open surgery: a long incision (cut) is made on your abdomen.
- Minimally invasive surgery: small incisions are made on your abdomen. Your surgeon will insert surgical instruments and a camera through these incisions to do the surgery.
Laparoscopic surgery is the term used for such minimally invasive surgery.In some situations, the surgery may also be performed with robotic assistance. The advantage of this robotic approach is evident when operating in difficult anatomical locations such as a rectal cancer within a narrow pelvis.
Right hemicolectomy
A right hemicolectomy removes the ascending (right side) colon. The rest of the colon will be attached to the small intestine.
Left hemicolectomy
A left hemicolectomy removes the descending (left side) colon. The right side of the colon will be attached to the sigmoid colon.
Subtotal colectomy
A subtotal colectomy removes the ascending (right side) colon and the descending (left side) colon. The small intestine will be attached to the sigmoid colon or the rectum.
Low anterior resection
A low anterior resection removes the rectum and the sigmoid colon. The rest of the colon will be attached to the remaining part of the rectum. You may need to have astoma pouch, but this is usually only for a short time and can be surgically reversed later.
Abdomino-perineal resection (APR)
An abdomino-perineal resection removes the rectum and anus. Since these parts of the colon are removed, you will no longer have an anus. You will need to have a permanent stoma pouch.
Cytoreductive surgery and HIPEC
CRS and HIPEC is the accepted treatment for colorectal cancers that have spread to the lining of the peritoneal cavity. It is an advanced stage of cancer usually involving several other abdominal organs.The aim of this surgery is to remove all the cancer within the abdomen. This is followed by HIPEC which is chemotherapy delivered at a high temperature into the abdominal cavity.It is a complex and extensive open operation performed by a surgical oncologist who has received special training and experiencein this treatment.
General complications after surgery
Colorectal surgery is associated with some known risks although every effort is made to minimse them during and after the operation. These include:
- Leakage at the joined sections of intestines
- Infection within the abdomen
- Post-operative bleeding
- Injury to the surrounding viscera