Researchers at the University of Texas MD Anderson Cancer Center have developed a novel breast cancer staging system called Neo-Bioscore which includes HER2 status of the tumor. This approach is built on increasing evidence that tumor biology knowledge is essential for a more accurate prediction of clinical outcomes, prognosis stratification and better therapeutic planning.
The research paper, “The Neo-Bioscore Update for Staging Breast Cancer Treated With Neoadjuvant Chemotherapy: Incorporation of Prognostic Biologic Factors Into Staging After Treatment,” was published in JAMA Oncology.
Stage stratification of breast cancer has historically relied on morphology observations such as size of the primary tumor, metastasis, and presence of disease in the lymph nodes. However, recent research has shown that the biology of individual tumors is extremely important in the choice of treatment, the patient’s response to the chosen therapy, and overall survival outcomes.
The new system builds on a previous staging breast cancer system developed and validated by MD Anderson researchers, the CPS+EG, which incorporates the preclinical stage, estrogen receptor status, grade, and post-treatment pathologic stage.
Researchers wanted to update the CPS+EG staging system by incorporating HER2 tumor status, as the CPS+EG system predated the routine use of trastuzumab (Herceptin), a drug approved for use as a single or conjugation therapy for the treatment of HER2-positive breast cancer. HER-2 (human epidermal growth factor receptor 2) is a cell-surface protein involved in the control of cell growth. HER2-positive is a term used to describe cancer cells that express high levels of this protein, leading to abnormal tumor growth and increased metastatic potential. Checking if a cancer is HER-2 positive can lead to a better planning of therapeutic strategies and more accurate information regarding a patient’s prognosis.
To validate the new Neo-Bioscore system, scientists reviewed the data of 2,377 MD Anderson breast cancer patients treated with neoadjuvant chemotherapy, which included anthracycline and/or taxane, and trastuzumab for those with HER2-positive disease. A CPS+EG score was attributed to each patient with HER2 status. The novel staging system Neo-Bioscore was constructed by adding a point to the CPS+EG score for HER2-negative tumors.
The results confirm the previously validated CPS+EG staging system, which improved prognostication of patients. Moreover, applying Neo-Bioscore led to a shift of the previous score, resulting in a more refined stratification in 1,786 (75 percent) of patients, reflecting the number of HER2-positive cancers.
“With this tool, I can give my patients the precise information they are looking for — a more refined prognosis. Also, with this data, we will know which patients are in greatest need of additional therapy,” first author Elizabeth Mittendorf, M.D., said in a news release. “Hopefully these findings will result in more informed conversations between doctor and patient.”