What does targeted therapy target?

To understand how targeted therapy works, one needs to know how specific cancer cells grow. Cells make up every tissue in the body. Each type of cell has a specific function. Cancer starts when certain genes in healthy cells change resulting in a mutation. The genes in the cells tell these cells how to make proteins that keep the cell working. So, if the genes change, these proteins change too. This makes cells divide abnormally or live too long. When this happens, the cells grow out of control and form a tumour.

So, drugs are being developed that target these changes. These drugs can block or turn off the signals that tell cancer cells to grow and divide, keep cells from living longer than normal or destroy the cancer cells.

Types of targeted therapy

There are several types of targeted therapy:

• Monoclonal antibodies: Block a specific target on the outside of cancer cells and can also send toxic substances directly to cancer cells
• Small-molecule drugs: Block the process that helps cancer cells multiply and spread
• Angiogenesis inhibitors: Keep the tissues around the tumour from making blood vessels which stops the growth of the cancer cells

What are the side effects of targeted therapy?

• The most common side effects seen with targeted therapies are:
• Diarrhoea
• Liver problems, such as hepatitis and elevated liver enzymes
• Skin problems
• Problems with blood clotting and wound healing
• High blood pressure
• Gastrointestinal perforation (a rare side effect)