CHEARS

Global cancer burden has risen to 19.3 million cases and 10 million cancer deaths in 2020. Cancer cells typically have changes in their genes that make them different from normal cells. Genes are part of a cell's DNA that guides the cell to act in certain manner. When a cell has certain gene changes, it doesn't behave like a normal cell. For example, gene changes in cancer cells might allow the cell to grow and divide very quickly. Learning these details has led to the development of drugs that can “target” these proteins or enzymes and block the messages being sent. Targeted therapy is sometimes called precision medicine or personalized medicine because they are made to exactly target specific changes or substances in cancer cells and these targets can be different even when people have the same type of cancer. Targeted drugs can block or turn off signals that make cancer cells grow, or can signal the cancer cells to destroy themselves without affecting the normal cells.

What are the types of targeted therapy?

1) Monoclonal antibodies

2) Small molecule inhibitors

3) Immunotoxins.

How does targeted therapy work?

Most types of targeted therapy work by interfering with specific proteins that help tumours grow and spread throughout the body. They treat cancer in many ways.

· Help the immune system destroy cancer cells.

· Stop cancer cells from growing.

· Stop signals that help form blood vessels.

· Deliver cell-killing substances to cancer cells.

· Cause cancer cell death.

· Starve cancer of the hormones it needs to grow.

How is targeted therapy different from chemotherapy?

Targeted therapy drugs have different mechanism of action as that of chemotherapy drugs.

Because of their targeted action, these drugs have an effect on the cancer cells and mostly leave normal, healthy cells alone. Traditional chemotherapy is cytotoxic to most cells, meaning it can damage normal, healthy cells in addition to damaging and killing cancer cells.

• Targeted drugs often work by blocking cancer cells from copying themselves. This stops a cancer cell from dividing and making new cancer cells. Traditional chemotherapy, however, kills cancer cells that have already been made.

Are there drawbacks to targeted therapy?

Targeted therapy does have some drawbacks.

• Cancer cells can become resistant to targeted therapy. For this reason, they may work best when used with other types of targeted therapy or with other cancer treatments, such as chemotherapy and radiation.
• Drugs for some targets are hard to develop. Reasons include the target’s structure, the target’s function in the cell, or both.

Overall rational combinations of targeted therapies directed to the hallmarks of cancer will be the key to cure.