Targeted therapies in cancer

Cytotoxic chemotherapy has traditionally provided the backbone of medical care for cancer. While chemotherapy remains the treatment of choice for many types of cancer, so-called 'targeted therapies' are now increasingly available within the clinic across a broad range of tumour types. Targeted therapies can inhibit specific molecular targets implicated in cancer or single oncogenic drivers, rather than affecting cell division or DNA synthesis. While often better tolerated, they can be associated with adverse events, which require specialist multidisciplinary management. Targeted therapies have changed cancer care, with tailoring to an individual patients' tumour, new approaches to dosing and disease assessment, but with an increasing burden on health economics. Rather than a disease-specific approach, these novel therapies may be of benefit in multiple cancer types. There are three main categories of targeted therapies: small molecule inhibitors, monoclonal antibodies and immunotherapies, which will be considered in this article.