Targeted therapy
Introduction
Targeted therapy refers to a type of cancer treatment that uses drugs or other substances to identify and attack specific types of cancer cells with less harm to normal cells. This form of therapy interferes with the specific molecules ("molecular targets") that are involved in the growth, progression, and spread of cancer.
Molecular Targets in Cancer
Cancer cells have certain unique features that differentiate them from normal cells. These features, known as molecular targets, are often proteins that are involved in the growth and spread of cancer cells. Targeted therapies are designed to interfere with these proteins, thereby inhibiting the growth and spread of cancer cells.
Some of the most common molecular targets in cancer include epidermal growth factor receptors (EGFR), human epidermal growth factor receptor 2 (HER2), and vascular endothelial growth factor (VEGF).
Types of Targeted Therapy
Targeted therapies can be classified into two main types: small molecule drugs and monoclonal antibodies.
Small Molecule Drugs
Small molecule drugs are small enough to enter cells easily, so they are used for targets that are inside cells. These drugs often work by blocking the process that helps cancer cells multiply and spread. Examples of small molecule drugs include imatinib (Gleevec), which targets the BCR-ABL protein in chronic myeloid leukemia, and gefitinib (Iressa), which targets the EGFR protein in non-small cell lung cancer.
Monoclonal Antibodies
Monoclonal antibodies are drugs that are designed to target specific cells. They work by attaching to specific targets on the surface of cancer cells. Examples of monoclonal antibodies include trastuzumab (Herceptin), which targets the HER2 protein in breast cancer, and bevacizumab (Avastin), which targets the VEGF protein in various types of cancer.
Mechanisms of Action
Targeted therapies work by blocking the growth of cancer cells in different ways. Some targeted therapies block the action of certain enzymes, proteins, or other molecules involved in the growth and spread of cancer cells. Others help the immune system kill cancer cells or deliver toxic substances directly to cancer cells and kill them.
Side Effects of Targeted Therapy
While targeted therapies are designed to affect only cancer cells, they can also affect healthy cells and cause side effects. The side effects of targeted therapy can vary widely and depend on the type of therapy. They can include skin problems, high blood pressure, fatigue, mouth sores, and decreased appetite, among others.
Future of Targeted Therapy
The future of targeted therapy looks promising, with many new targeted therapies currently being studied in clinical trials. These include therapies that target cancer stem cells, therapies that use nanoparticles to deliver drugs directly to cancer cells, and therapies that use the body's immune system to fight cancer.
See Also
Chemotherapy Radiation therapy Immunotherapy Cancer stem cells Nanomedicine