What Is Precision Medicine for Cancer?
Our bodies are made up of trillions of cells, and within each cell are genes. Genes contain specific information that determines many of our traits, such as eye color, skin color and height. Yet even beyond physical characteristics, researchers have discovered that genes also play a role in our health and how diseases, including cancer, develop within the body. This has led to a new approach to medicine, known as precision medicine, where medical decisions and treatments are guided by each individual’s genetic make-up.
Two people with the same “type” of cancer can have very different outcomes. One person’s cancer may grow bigger, spread faster, or may not respond to a treatment that worked for the other person. Why is this the case?
Simply put, cancer occurs when abnormal cells in our body grow out of control. This abnormal growth is often the result of mutations, or changes, within specific genes. As researchers have studied this process, they’ve found that many different combinations of mutations can occur, and cancer is not “one-size-fits all”, even when it originates from the same part of the body.
This discovery provided researchers with some powerful information. Once mutations in the cancer cells were identified, treatments were developed to target cells with those abnormal changes and stop the cancer from progressing. This is called targeted therapy, and it is the crux of precision medicine. Now doctors can analyze a patient’s tumor and look for the genetic changes that are present. Instead of following a universal treatment plan because a patient has breast cancer or lung cancer for example, a treatment may be selected that works best for the specific tumor cell mutations that are seen in an individual patient.
In addition to helping select the most effective treatment, there are other benefits of precision medicine:
It allows for more accurate diagnoses of cancer (and other diseases).
It helps patients avoid unnecessary treatments and therefore, potentially harmful risks or side effects.
It can help identify patients who may be at risk for certain types of cancer, like those who have the BRCA-mutation and are at a higher risk for developing breast cancer, so that interventions may be performed to lower the risk.
It may also take non-genetic characteristics, like lifestyle and environment, into consideration since they impact disease and treatment outcomes.
In his 2015 State of the Union address, President Obama announced the launch of the Precision Medicine Initiative and Congress funded $215 million dollars to advance research and development in the area. It aims to boost precision medicine across the board, but much emphasis will be placed on cancer. The Initiative is designed to:
Create more clinical trials for precision medicine to lead to better treatment options for cancer
Learn more about why some tumors become resistant to treatment
Collect genetic data, samples, and health information from at least 1 million volunteers
Develop a national database to consolidate this information for researchers and health care providers
Use this information to construct models that predict how different cancer cells will respond to treatment
Precision medicine has come a long way, but we still have a lot to learn. Not every type of cancer has a targeted therapy available to treat it, and some doctors simply don’t have precision medicine technology available within their practices. At this time, standard treatments for cancer, like radiation and chemotherapy, are still the norm. Yet with the early successes we have seen, if you have cancer, ask your doctor if genetic testing and precision medicine are appropriate for you.