Targeted therapy is a form of cancer treatment that uses drugs but is different from traditional chemotherapy in the method of operation of the drugs. In targeted therapy, the drugs used identify cancer cells specifically, sparing normal cells, resulting in less harm to normal cells and lesser side effects. Some kinds of targeted therapy block the effect of some enzymes, proteins, or other molecules that aid in the growth and spread of cancer cells. Other kinds of targeted therapy help by sending toxic substances directly to cancer cells, destroying them or helping the immune system kill off the cancer cells.

Targeted therapy is different because it works on exact molecular targets that are related to cancer while other chemotherapies work on all types of cells that multiply fast, both healthy and cancerous. Some other types of chemotherapies kill cells on the whole while targeted therapy blocks only some kinds of cancerous cells. This type of cancer treatment aids in restricting the tumour from creating new blood vessels to help its growth by stopping signals sent from the tumour. Targeted therapy is a form of systemic therapy because it can access cancer cells anywhere in your body and is used to treat certain types of colorectal cancer, lung cancer, breast cancer and melanoma.