Chemotherapy is the administration of drugs that have been designed to kill cancer cells by interfering with their growth and division. There are many chemotherapy drugs, and each works in a different way. For example, some stop cells from being able to make a successful copy during the process of cell replication, whereas others prevent separation of the cells during cellular division (mitosis). Cells are more prone to damage from chemotherapy when they are dividing, and as cancer cells divide more frequently than normal cells, they are more susceptible to its effects. In recent years, new drug treatments called ‘biological therapies’ or ‘targeted therapies’ have been introduced that are often given alongside chemotherapy. They include monoclonal antibodies and tyrosine kinase inhibitors (TKIs). Targeted therapies hinder cancer cell growth by working on features that are particular to cancer cells such as over-expression of growth factors that promote cancer cell division. Together, chemotherapy and targeted therapies are referred to as ‘systemic anti-cancer therapy’.

The aims of systemic anti-cancer therapy are to maximise the damage to cancer cells and minimise the harm to healthy cells. This can be achieved by:

Using combinations of drugs: