Precision medicine

No two cancers are the same. No two people are the same. So why treat people with cancer in the same way?

All cancer treatment is tailored to a certain extent. But in the past, care has been mostly based on the type and location of the cancer and a patient's personal situation.

Precision medicine, which is also called personalized medicine, takes personalization to a new level. It helps doctors choose treatments based on a person's genes and the genetic and molecular profile of the cancer. Personalizing treatment in this way may lessen harmful side effects, reduce damage to healthy cells and make it more likely that a treatment will work.

Precision medicine can also be used to predict cancer risk, diagnose cancer earlier and help people make treatment decisions that are right for them.

Cancers are caused by a change in, or damage to, one or more genes. These mutations might be inherited from our parents, caused by exposure to cancer-causing substances or be the result of the natural aging process.

The more we learn about the links between genetic changes and cancer, the better we become at predicting and treating disease. For example, if you have certain genetic traits, your doctor may suggest regular tests to help spot cancer early or encourage you to make lifestyle changes to help lower your risk.

Genetic testing can also help doctors predict if a cancer is more likely to return after treatment.

In the past, cancer was often treated based on where it was found, such as in the breast or in the lung. With precision medicine, doctors focus less on the location and more on the nature and specific features of the cancer.

Personalizing treatment in this way means that two people who have breast cancer might be offered very different treatments. Meanwhile, people with different cancers may have the same type of precision therapy because their cancers have similar characteristics.

Many people with cancer will still be treated with surgery, radiation therapy or chemotherapy. But precision medicine allows doctors to add newer, targeted treatments to get the best possible results. Treatments such as targeted therapy and immunotherapy are considered precision medicine.

Targeted therapy uses drugs and different ways of releasing them in the body to target specific genes and proteins that are involved in the growth and survival of cancer cells.

To develop targeted therapies, researchers first identify the genetic changes that help a tumour grow. This could be a mutation or a specific protein found in cancer cells but not healthy cells. Once researchers have identified the change, they develop treatments to target it.

Targeted therapies can stop the growth and spread of cancer cells by turning off growth signals, preventing cells from living longer than normal or destroying cancer cells.

Immunotherapy uses the immune system to fight diseases such as cancer. It works by strengthening or restoring a patient's natural immune defenses to help them recognize and destroy cancer cells. Alternatively, immunotherapy can involve creating substances in a lab that mimic immune system components and enhance a patient's immune response.

Immunotherapy research is growing quickly. There are many different types of cancer immunotherapy, such as immunomodulators, monoclonal antibodies and cancer vaccines, and many more in development.

Immunotherapy works better for some types of cancer than for others. Just like targeted therapy, it can be used alongside other treatments to maximise results.

In recent years, researchers have learned a lot about how genes and genetic mutations can increase the risk of cancer and cause a cancerous tumour to grow and spread. This knowledge is helping researchers develop precision medicines that are more effective and cause fewer side effects. But researching precision medicine is a complex, slow and challenging process.

Although our understanding of cancer genetics is growing rapidly, precision treatment is not available for all cancer types and subtypes. And in some cases, precision treatments are only available in clinical trials.

The cost, availability and huge volumes of data involved in genetic testing are some of the challenges associated with precision medicine research. However, advances in technology and worldwide cooperation are helping scientists understand more about cancer genetics, how precision treatments work and, in some cases, why they stop working. This progress relies on people with cancer agreeing to donate samples of tissue for research purposes.