METABRIC
Background
Breast cancer is not just one uniform disease; the specific genes and proteins that are present in the tumor cells (the molecular signature) show significant variation from person to person. These differences affect the way in which individual breast tumors respond to chemotherapy and other cancer treatments.
Breast cancers can already be grouped into several different classes based on molecular signature. Physicians depend on this information when deciding how to treat each new breast cancer patient. For example:
- Tumours will only respond to hormone treatment if they contain the estrogen receptor or progesterone receptor proteins that bind to female hormones and pass their messages on to the cell.
- Only tumours that contain the human epidermal growth factor receptor 2 (HER2) protein will respond to chemotherapy using herceptin.
Directing treatments only to those patients with the best chance of responding to them avoids putting people through unnecessary and debilitating treatments, and ensures that the resources available for breast cancer treatment are used in the most efficient and beneficial way.
Aims and Relevance
METABRIC (Molecular Taxonomy of Breast Cancer International Consortium) is a Canada-UK project that aims to classify breast tumours into further subcategories, based on molecular signatures that will help determine the optimal course of treatment. Specifically, we hope to identify the following groups of patients based on the molecular properties of their tumours:
- Patients whose disease has not spread to the lymph nodes and who are at very low risk of relapse. These people can potentially be spared unnecessary rounds of chemotherapy.
- Patients whose tumours have spread to the lymph nodes, but contain the estrogen receptor. These people can potentially be treated with hormone therapy alone.
- Patients whose tumours have spread to the lymph nodes and do not contain the estrogen receptor, but have a good prognosis if treated with alternative drugs.
- Patients with an aggressive disease who are at increased risk of relapse. These people would benefit the most from preventative therapy and intensive follow-up after the original disease is treated.
Achieving any one of these objectives would help physicians to individually tailor breast cancer treatment to give each patient the best possible chance of survival.