Colorectal cancer is not just confined to the intestines

Colorectal cancer, or cancer of the colon and the rectum, is the most common cancer in Singapore. It affects about one in every 20 men and one in every 30 women here.

While this deadly cancer develops from the cells of the large intestine, it can spread to other parts of the body, particularly the liver. This happens when the cancerous cells in the colon enter the bloodstream, circulating to the lymph nodes in the region and subsequently to vital organs like the liver.

When colorectal cancer spreads in this way, it is known as colorectal liver metastasis and is considered late stage cancer. However, the good news is that colorectal liver metastasis can be treated by a liver surgeon who will remove the cancerous cells in the liver for a potential cure in about 20 per cent of patients.

Dr Chan Chung Yip​, Head & Senior Consultant, Department of Hepato-pancreato-biliary and Transplant Surgery at Singapore General​ Hospital​ (SGH), a member of the SingHealth​ group, answers some of the common questions on the surgical treatment of colorectal liver metastasis.

  1. How is the operation done?

  2. The operation is intended to remove all cancer-bearing areas in the liver, while retaining enough liver reserves for the person’s needs. This surgery is usually performed as an open surgery, and requires a cut of about 15-30 cm over the abdomen to gain access to the liver. Some cases may be suitable for minimally invasive surgery (keyhole surgery). In keyhole surgery, several small incisions are made over the abdomen in order to insert instruments and a camera system to perform the surgery. A slightly longer cut may be made at the end of the surgery to retrieve the parts of the liver that have been removed.

  3. How many surgeries will I need?

  4. Most cases will only require a single surgery to remove all cancer-bearing areas. However, in rare situations, removing all cancerous areas at one go may leave too little liver reserves for the person’s needs. In such a situation, the surgery may be staged, i.e. the cancer-bearing areas are removed in a step-wise fashion over two separate surgeries to allow the liver to regenerate in between the two surgeries.

  5. What are the risks?

  6. Any type of liver surgery has the potential for severe complications. Besides the anaesthetic risks, the main surgical risks are heavy bleeding, infections, bile leakage, liver failure and death. However, major liver surgery is still relatively safe, and the risk of death from the surgical procedure is less than 5 per cent in specialised liver units. Besides bleeding, a primary cause of operative death is liver failure after surgery, due to insufficient liver remaining following the removal of the cancerous areas. In some cases where this situation is anticipated, your surgeon may elect for you to undergo an additional procedure known as “portal vein embolisation” prior to the surgery in order to “grow” the liver to a sufficient size for the surgery to be undertaken.

  7. How long do I need to stay in hospital? Do I need to stay in the ICU?

  8. Most routine cases do not need monitoring in the ICU after the surgery. It is usual to be nursed in the high-dependency ward for a couple of days, and then in the general ward for another few days. The average length of stay is about seven days.

  9. Is there any more treatment after the operation?

  10. Depending on the chemotherapeutic regime that has been designed for you, you may require further rounds of chemotherapy after you have recovered from the surgery.

  11. After the surgery, what are the chances of the cancer coming back?

  12. The factors that determine the risk of the cancer coming back include the stage of the colorectal cancer, whether the cancer had spread to the liver at the time of diagnosis of the primary colorectal cancer (synchronous), or if it was discovered more than six months after the initial diagnosis of cancer (metachronous).​Other factors that determine the risk of the cancer coming back include the response to chemotherapy, and the number and size of the cancer nodules in the liver. If the cancer recurs, and it is limited to the liver only, there is still the potential for further liver surgery or ablation to remove or kill off the cancer areas and improve the chances of survival. Overall, in a third of cases, the cancer does not come back and can be cured.

Ref: T12