Precision medicine helps determine the most effective treatment for individual types of cancer and helps avoid the risks and side effects of unnecessary treatment.
Source: Susan G. Komen Breast Cancer Foundation
What is precision medicine?
There’s no standard medical definition for precision medicine (also called personalized medicine). So, you may hear this term used in different ways.
In general, precision medicine describes tailoring (or adapting) the treatment of a disease (such as breast cancer) to give the most effective treatment for each person’s disease.
To do this, it uses information that can include:
- A person’s genes
- Non-genetic personal characteristics (for example, lifestyle factors)
- Molecular (cell) characteristics of the disease
The importance of precision medicine
The goal of precision medicine is to give the most effective treatment for each person’s breast cancer. This involves:
- Getting the best results, while avoiding unnecessary treatment.All treatments for breast cancer (including surgery, radiation therapy, chemotherapy, hormone therapy and targeted therapy) have risks and side effects. Avoiding unnecessary treatments avoids these risks and side effects.
- Developing therapies to target specific tumors or specific cellular pathways that lead to tumor growth and identifying the people who will respond best to them.
Some factors that help personalize treatment plans are related to an individual. For example, some treatments are chosen based on whether or not a woman has entered menopause.
Most factors that help personalize treatment however, are related to the breast cancer itself.
Breast cancers differ in many ways, especially at the molecular (cell) level. Factors related to the tumor give information on prognosis and help personalize treatment to give the most benefit to each person.
How is treatment personalized?
Although treatment is becoming more personalized, we cannot predict how any one person will respond to a certain treatment.
Treatment is personalized based on the groups a person belongs to (such as people with HER2-positive breast cancers, people with lymph node-positive breast cancers, women who are premenopausal and other groups) rather than to a specific person.
The results of clinical trials show us which therapies are most effective in which groups of people. If a certain therapy is effective in a group you belong to, then your treatment plan can be personalized to include that therapy.
For example, clinical trials have shown the targeted therapy trastuzumab (Herceptin) lowers the risk of recurrence of HER2-positive breast cancers. If your tumor is HER2-positive, your treatment plan is usually personalized to include trastuzumab.