Biological Therapy

Antibodies
Gene therapy
Haemopoietic Growth Factors
Hormone Therapy
Immunotherapy
Interferons
Interleukins
Monoclonal Antibodies

Biological therapy (or biotherapy as it is sometimes called) is considered the fourth arm of cancer treatment (after surgery, radiotherapy and chemotherapy). Biological therapy encompasses a variety of anti-cancer treatments. As opposed to cytotoxic agents, biological agents act indirectly to assist in tumour killing.

Antibodies:

Antibodies are genetically engineered substances that target specific sites on our cells. Targets/uses include: Cancerous bone marrow in patients with lymphoma/leukaemia, collecting stem cells from bone marrow or blood, to carry agents to tumor cells to enable cell killing, and receptors which allow tumour growth (in breast cancer).

Gene Therapy

The use of specific DNA to correct defective cell function or to enhance the immune system. This is still confined to clinical trials.

Haemopoietic Growth Factors

Colony stimulating factors are used as alternatives to bone marrow transplants and to treat neutropaenia resulting from chemotherapy, due to their action in stimulating production of blood cells.

Hormone Therapy

It works by interfering with the production or action of particular hormones. Hormones are naturally produced substances that act as chemical messengers to assist in the normal control and functions of the bodies cells. For example, oestrogen can promote breast cancer growth and anti-oestrogen drugs such as Tamoxifen are used to inhibit this process.

Hormone Therapy Drugs:

Immunotherapy

Cancers and many cancer treatments have an immunosuppressive action, that is, they reduce our ability to naturally fight cancer. Immunotherapeutic drugs work by strengthening the immune system, which is the body's natural defence mechanism.

Immunotherapy Drugs:

Interferons

Signalling molecules with a multitude of actions including stimulating the body's immune system and limiting the division of cells in cancers. Malignant melanoma, chronic myeloid leukaemia, renal cell carcinoma, myeloma are all cancers where Interferon has been of benefit in treatment. Interferon is injected below the skin; the major side effects of interferon therapy are fatigue and flu-like symptoms.

Interleukins

These are signalling molecules with widespread activity across multiple organ systems; especially important in activating T lymphocytes. Interleukins have been used to treat Renal Cell Carcinoma and Malignant Melanoma. Complications of treatment include low blood pressure, pulmonary oedema, vitiligo and autoimmune thyroiditis.

Monoclonal Antibodies

These are made to react with specific antigens on the surface of cancer cells. This means that cancer cells are targeted directly, which may cause less systemic toxicity than chemotherapy or radiotherapy. Monoclonal antibody therapy is "passive", meaning it doesn't require an active immune system. Monoclonal antibodies are generally developed in mice and may be naked or conjugated. The side effects of naked monoclonal antibody therapy are usually mild, and similar to an allergic-type reaction. If experienced, they are usually seen at the time of infusion. The myelosuppression seen with chemotherapeutic drugs may also be seen with monoclonal antibody therapy. This may result in an increased bleeding and infection risk.