INTRODUCTION

Treatment modalities include:

1. Surgery
2. Chemotherapy
3. Radiotherapy
4. Biological therapy

Surgery is the mainstay of treatment in colorectal cancer. Depending on the stage of the disease, some patients might need chemotherapy after surgery to reduce the risk of recurrence. On the other hand, for rectal cancer, some patients might benefit from radiochemotherapy before surgery to shrink the tumour.

SURGERY

The part of the bowel involved by cancer will be removed and the remaining two ends will be joined together. Sometimes, when the tumour is near to the anus, a temporary stoma is needed. This temporary stoma will be closed after further tests which are done a few months later confirming that the joining part is intact. Unfortunately,  in a minority of cases where the tumour is too near to the anus, the  entire rectum and anus needs to be removed and the patient will have to carry a stoma bag permanently.

Surgery is the mainstay of treatment in achieving cure. However, in patients with stage IV disease, sometimes surgery is also advised to avoid the potential complications of colorectal cancer such as bowel obstruction, massive bleeding and tumour perforation, which can be life threathening.

THERAPY


CHEMOTHERAPY

Chemotherapy has been shown to increase the chance of cure in certain groups of patients. After surgery, the pathologist will examine the specimen and report on the stage of the tumour. Based on the stage of the disease, the oncologist will decide whether the patient will benefit from chemotherapy. If the patient is fit, chemotherapy will be prescribed to all patients with stage III disease, after discussing the benefits and adverse effects of chemotherapy with the patient. However, chemotherapy might be beneficial in a small group of patients with stage II disease. For stage IV  disease, even though chemotherapy is unlikely to cure the patient, it is used with the intention of improving symptoms and prolonging survival.

Most chemotherapy is given by injection or oral form. Common side effects of chemotherapy include nausea and vomiting, hair loss, mouth sores, diarrhoea and fatigue.


RADIOTHERAPY

Radiotherapy involves the use of high-energy X-rays to kill cancer cells. It will only affect the cancer cells in the treated area. Even though it is used occasionally in colon cancer, it is usually used in rectal cancers. Based on the staging tests in rectal cancer (by endorectal ultrasound or MRI), radiotherapy might be given before surgery to shrink the tumour and to reduce the risk of tumour recurrence later. Sometimes, radiotherapy is given after surgery if it is not given before surgery. For patients with inoperable tumour, radiotherapy might be used to relieve symptoms like pain and bleeding.

Common adverse effects of radiotherapy include fatigue, skin changes at the site where the treatment is given, loss of appetite, nausea and diarrhoea.

BIOLOGICAL THERAPY

Biological therapies, such as monoclonal antibodies, are treatments that use substances that occur naturally in the body. It is sometimes used in stage IV colorectal cancer.

The most common side effects of biological therapies for colorectal cancer are tiredness, diarrhoea, skin changes, a sore mouth, weakness, loss of appetite, low blood counts, and swelling of parts of the body due to a build up of fluid.


TREATMENT OF TUMOUR METASTASES 

In most stage IV non-colorectal cancers, presence of tumour metastasis in other organs, eg. lung and liver indicates a poor outcome. However, the prognosis of stage IV colorectal cancer is not as bad as other cancers. Therefore, patients with colorectal  cancer which has spread to other organs (i.e. liver and lung) can still be cured if the number of tumour metastases is small and are treatable. Modalities used to treat liver spread include ablating (burning) the cancer, chemoembolisation (delivering chemotherapy directly into the liver lesions) and surgery (surgical removal of lung or liver lesions).
 

 

Updated:: 13/03/2019 []