A researcher with the Breast Health Center at Women & Infants Hospital, a Care New England facility, recently presented the results of a study showing that women with Stage 2 or 3 triple-negative breast cancer (TNBC) who have a pathologic complete response (pCR) to chemotherapy before surgery are more likely to survive compared to those who had more than minimal residual invasive disease during surgery at the prestigious San Antonio Breast Cancer Symposium.
The presentation built upon research William Sikov, MD, presented at the 2013 Symposium. At that time, his work demonstrated that adding either of two drugs – carboplatin or bevacizumab - to standard chemotherapy many women with TNBC receive before surgery were more likely to have no residual cancer detected at surgery.
This year, Dr. Sikov's presentation offered more data showing the importance of achieving that type of response to preoperative chemotherapy.
"Our new data shows that patients who had a pCR had far superior outcomes compared to those who did not have a pCR," said Sikov. "After three years of follow-up, only nine percent of patients who had a pCR had developed a distant recurrence and only six percent had died, compared to 27 percent and 25 percent, respectively, of patients who did not have a pCR.
"While this is important, our study was not large enough to have the statistical power to determine whether adding carboplatin or bevacizumab to standard neoadjuvant chemotherapy improves long-term outcomes," continued Sikov. "Given these limitations, at the present time, we cannot say that either carboplatin or bevacizumab should be considered part of the standard neoadjuvant chemotherapy regimen for stage 2 or 3 TNBC."
The clinical trial enrolled 443 patients with operable Stage 2 or 3 TNBC. They were randomly assigned to get either the standard chemotherapy regimen or to get the same treatment with either or both of the two additional drugs.
Dr. Sikov and his colleagues found that, at three years after starting the study treatment, patients who had no residual invasive cancer detected in either breast tissue or lymph nodes had a 70-percent reduced risk of disease recurrence and an 80-percent reduced risk of death compared with those who were found to have residual cancer in either the breast or lymph nodes at surgery.
"In regards to the question as to whether there is a benefit to adding either carboplatin or bevacizumab to standard chemotherapy for Stage 2 or 3 TNBC, it is important to highlight that this is not a negative study," said Dr. Sikov. "Rather, it is underpowered, meaning that it was not designed to be large enough to prove or disprove a benefit for either agent. Our results need to be considered alongside data from prior and ongoing studies with these agents in TNBC.
"Going forward, the question is whether we want to commit the additional patients and resources necessary to answer this question or instead focus our research efforts on other opportunities to improve outcomes for TNBC."
This study was supported by the National Cancer Institute's Cancer Therapy Evaluation Program, Genentech, and the Breast Cancer Research Foundation.
Women interested in making an appointment with Dr. Sikov or other providers with the Breast Health Center at Women & Infants can call (401) 453-7520.
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