In a nutshell
This study evaluated the impact of breast cancer subtypes on disease prognosis in patients with metastatic breast cancer (cancer that has spread outside the breasts to the other parts of the body).
Some background
Breast cancer is classified into different subtypes depending on the presence or absence of certain receptors (proteins found on the surface of the cancer cells). Some breast cancers grow in response to female hormones (estrogen or progesterone), via their receptors. These cancers are called hormone receptor-positive (HR+) breast cancers. Other types of breast cancer do not have these receptors and are called hormone receptor-negative (HR-) breast cancers. Human epidermal growth factor receptor 2 (HER2) is a protein found on the surface of some breast cancer cells (HER2+ breast cancer) that promotes tumor growth in these cells. Cancer that tests negative for estrogen receptors (ER-), progesterone receptors (PR-) and human epidermal growth factor receptor 2 (HER2-) is referred to as triple-negative (TN) breast cancer. These subtypes of breast cancer do not only influence patients’ treatment options but also affect disease prognosis (outcome). This study, aimed to test the impact of these subtypes on the prognosis of patients with metastatic breast cancer.
Methods & findings
This study included a total of 798 patients with metastatic breast cancer. 527 patients were classified under the HR+/HER2- subtype, 64 patients had a HR-/HER2+ subtype, 123 patients had TN breast cancer and 84 patients had HR+/HER2+ subtype. The main parameters measured were patient survival rates after metastasis.
Results showed that patients with TN subtype had the least survival period of 8.8 months. Survival was 19.8 months for patients with the HR-/HER2+ subtype and 24.8 months for patients with the HR +/HER2-subtype. Patients with the HR+/HER2+ subtype had the longest survival period of 34.4 months. Even after adjusting possible variables/factors that could have influenced the association between the subtypes and survival, HR+/HER2+ subtype had better survival outcome than the other subtypes.
The bottom line
In summary, this study showed that metastatic breast cancer subtypes affect disease outcomes. This means that patients with TN or HR-/HER2+ subtypes may need more aggressive therapies in order to improve their prognosis.
What’s next?
Discuss with your physician the available treatment options to determine which choice is best in your situation.
Published By :
Breast Cancer Research and Treatment
Date :
Oct 09, 2013
