For the last twenty or thirty years, the outcome from treatment of cancer has remained relatively static with approximately 50% survival patients diagnosed with the disease. This has remained relatively constant even with the advent of new chemotherapy drugs.
Iressa (Gefitinib) is a specific antibody that blocks EGFR (Epidermal Growth Factor Receptor) which is found in increased quantities on lung cancer cells. Addition of Iressa to treatment of people whose tumours specifically express this receptor in large quantities, has made a big difference in decreasing the rate of cancer cell growth and response to treatment. Iressa is used her in Australia to treat lung cancer patients whose tumours have large amounts of the extra receptor. The latest agent to be released in the war against cancer are Bevacizumab (Avastin) and Cetuximab (Erbitux). Bevacizumab is a drug which blocks VETF (Vascular Endothelial Growth Factor Receptor). This receptor is found in new blood vessels. When cancer cells are growing and spreading, they stimulate the growth of new blood vessels to allow them to grow bigger. Blocking the receptor in the blood vessels allows blood vessel growth helps to stop the tumour from growing. This also allows the chemotherapy drugs to better penetrate the cancer. This drug is showing great promise in bowel cancer and may also be used in kidney cancer. Cetuximab (Erbitux) is another agent that attacks a protein called EGF (Epidermal Growth Factor). This drug blocks the protein on the cancer cells surface that stimulates the cancer cell to grow. This receptor protein is found in excess numbers in certain cancer cells. This drug is looking to be very usual in bowel cancer and also in head and neck cancer. Dr Chris Millross, Australian Radiation Oncologist Specialist, presented data at the recent Medical Oncology Group of Australia Meeting (Australia’s Cancer Specialists Annual Scientific Meeting) which showed that Cetuximab dramatically increased the response of aggressive head and neck cancers to radiotherapy. It did this without causing any major side effects. As well as that, Erbitux is looking to be very useful in colon cancer. There are a host of other monoclonal antibody treatments currently under development many of which are being trialled here in Australia. The abilities of these treatments to increase the response of cancer sufferers to treatment such as radiotherapy and chemotherapy is very exciting for everybody involved in cancer care here in Australia. It is widely believed that the use of these agents will ultimately lead to more people being cured and surviving from this disease.