A new breast cancer staging system developed by researchers at MD Anderson Cancer Center finds that incorporating tumor biology is a critical prognostic indicator for women who undergo neoadjuvant, or pre-surgical, therapy for breast cancer.
The Neo-Bioscore staging system, published in JAMA Oncology, incorporates HER2 status, thereby allowing more precise prognostic stratification of all breast cancer subtypes. Understanding a patient’s individual response to therapy could inform clinicians of which patients would benefit from additional therapy.
Historically, breast cancer patients have been staged by the size of the primary tumor, metastasis or disease in the lymph nodes at the time of presentation. Yet, says Elizabeth Mittendorf, M.D., Ph.D., associate professor of Breast Surgical Oncology, this fails to take into account the biology of the tumor, which has shown to be critically important.
These findings build on MD Anderson’s earlier development of a breast cancer staging system, CPS+EG, which incorporates preclinical stage (CS), estrogen receptor status (E), grade (G) and post-treatment pathologic stage (PS).
However, explains Mittendorf, the CPS+EG system predated the routine use of trastuzumab (Herceptin) in the neoadjuvant setting, so the staging system was limited by its inability to provide prognostic information for HER2-positive patients.
“Our initial study found that if we incorporate the clinical and pathologic stage, then we can have more refined stratification of patients’ prognosis,” says Mittendorf, the study’s corresponding author. “We also found that biological factors, such as estrogen receptor status and grade were important.”
“This new staging system, Neo-Bioscore, which adds HER2 status, is another piece of the puzzle showing that the biology of breast cancer, with respect to prognosis, is critically important,” says Kelly Hunt, M.D., professor and chair, ad interim, Breast Surgical Oncology, also a corresponding author on the study.
Learn more about the new breast cancer staging system in the MD Anderson Newsroom.