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Treatment Efficacy Score a Better Way to Predict Long-Term Survival in Breast Cancer Trials

May 11, 2022

In a study led by Dr. Lajos Pusztai, Professor of Medicine (Medical Oncology) at Yale Cancer Center, researchers across various institutions, and on behalf of the I-SPY consortium, developed a novel continuous residual cancer based metric to compare neoadjuvant chemotherapy efficacy between randomized trial arms in preoperative breast cancer trials. Known as the Treatment Efficacy Score (TES), this new metric describes how effective a drug is in shrinking cancer in a group of patients.

TES can capture the relative efficacy of one treatment (e.g., experimental treatment) over the other (e.g., standard of care) by analyzing the distribution of the continuous Residual Cancer Burden (RCB) score. RCB scores quantify the amount of invasive cancer after neoadjuvant chemotherapy by combining tumor size, cancer cellularity, and lymph node involvement into a single continuous score. Prior to the development of this metric, only the difference in pathologic complete response (pCR) rate between two arms of a randomized preoperative clinical trial was being used to predict long-term survival which fails to capture the downstaging impact of treatment on cancers with less than complete response.

The findings were published in the Annals of Oncology.

“TES can be used to compare two arms of a trial and predicts long-term survival better than just the difference in pCR rate between the arms,” explained Dr. Pusztai. “The correlation between TES and survival was higher than the correlation between pCR rate difference and survival.” TES is now available for use via a free web tool at

Submitted by Emily Montemerlo on May 12, 2022