Chemotherapy and targeted therapies

Chemotherapy and immunotherapy are often recommended in a treatment plan. They may have side effects but, if recommended, this usually means the benefits are likely to outweigh the adverse effects.

Chemotherapy and targeted therapies (Immunotherapy) for bowel cancer

Chemotherapy treatment involves the administration of drugs that either kill cancer cells or prevent them from dividing. When given by mouth, or by injection or infusion into muscle or the bloodstream, it is termed systemic chemotherapy. When placed directly into the cerebrospinal fluid, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas. This is known as regional chemotherapy.

There are a number of medicines used in New Zealand for the treatment of bowel cancer. A number of chemotherapy drugs (for both early stage and metastatic bowel cancer) are publicaly funded in New Zealand by government funding agency PHARMAC. These are available to patients at no charge. These funded medicines are often used in combination with immunotherapy drugs in the treatment of metastatic bowel cancer.

Immunotherapy drugs
Also known as ‘targeted’ therapies, are designed to selectively target cancer cells and the mechanisms that encourage their growth. They are currently not publicly funded in New Zealand however are available through co-share payment plans with pharmaceutical companies. 

These plans assist with the purchase of the drugs but the patient is still responsible for the cost of administration in a clinic or hospital. Your oncologist may mention these to you, if appropriate for your treatment plan and you may enquire about them as part of your treatment discussion.

How does immunotherapy work?
Immunotherapies act in a more specific way than chemotherapy and are often used in combination with chemotherapy medicines. Immunotherapies target specific cancer cells and the mechanisms that encourage their growth by using parts of our immune system to destroy cancer cells, either by stimulating the natural defenses of our immune system so it works harder (and smarter) to find and attack cancer cells, or by mimicking our immune system, helping to restore or improve the way that system works to find and attack cancer cells.

Immunotherapy is now an important part of treatment for metastatic bowel cancer and new treatments are being developed, tested, and released every year.

Funded chemotherapy treatments

A number of chemotherapy drugs are fully funded in New Zealand for the treatment of both early stage and metastatic bowel cancer. Your oncologist will discuss whether chemotherapy will be of benefit to you.

Most guidelines do not recommend chemotherapy for Stage II bowel cancer although patients at higher risk can be offered chemotherapy with a similar regimen to Stage III patients.

Drugs funded for use in New Zealand are:

  • 5-FU (5-fluorouracil)
  • Capecitabine (Xeloda)
  • Irinotecan (Camptosar)
  • Oxaliplatin (Eloxatin)

A combination of two or more drugs is common, for example:

  • FOLFOX (5-FU + leucovorin* + oxaliplatin)
  • FOLFIRI (5-FU + leucovorin + irinotecan)
  • FOLFOXIRI (5-FU + leucovorin + oxaliplatin + irinotecan)
  • CAPOX or XELOX (capecitabine + oxaliplatin)

* Leucovorin is a reduced folic acid. Leucovorin is used in combination with other chemotherapy drugs to either enhance effectiveness, or as a “chemoprotectant”