Breast Cancer Specialist Presents Positive Results for Triple-Negative Breast Cancer Presurgery Chemotherapy Benefits

A breast cancer specialist and clinical researcher at Women & Infants Hospital of Rhode Island presented research yesterday at the 2014 San Antonio Breast Cancer Symposium showing that adding either the chemotherapy drug carboplatin or the blood vessel-targeting drug bevacizumab to the standard treatment of chemotherapy before surgery helped women who have the basal-like subtype of triple-negative breast cancer.

"We found that adding either carboplatin or bevacizumab to standard preoperative chemotherapy increased pathologic complete response rates for women with basal-like cancers - that is, it increased the proportion of women who had no residual cancer detected at surgery. At the same time, we found that while carboplatin had a similar effect in the smaller group of triple-negative patients with nonbasal-like cancers, adding bevacizumab actually decreased response rates for women with nonbasal-like cancers," says William M. Sikov, MD, associate chief of clinical research with the Program in Women's Oncology at Women & Infants and associate professor of medicine at The Warren Alpert Medical School of Brown University.

Last year, Sikov and colleagues reported in a randomized, phase II clinical trial called CALGB/Alliance 40603 that adding either carboplatin or bevacizumab to standard preoperative chemotherapy increased pathologic complete response rates in 443 women with operable stage II or III triple-negative breast cancer. These latest results are based on analysis of tissue samples obtained before patients started treatment, correlated with findings at surgery after treatment. Pretreatment tumor samples from 360 of the patients showed that 314 were basal-like and 46 nonbasal-like.

"We have also looked at expression of variety of gene signatures in the pretreatment tissue samples to determine if they benefit from the addition of bevacizumab or carboplatin" Sikov says. "We found that gene signatures characteristic of high proliferation rates and low estrogen-receptor signaling, which are both considered characteristics of more aggressive disease, are associated with higher rates of response rates overall and increased benefit from adding bevacizumab."

Other studies using tissue and blood samples obtained from the patients treated on this study - funded by the National Cancer Institute, Roche-Genentech, and the Breast Cancer Research Foundation – are ongoing.

Triple negative breast cancer

Women who develop breast cancer under the age of 40 are more likely to have triple negative breast cancer than older women with breast cancer. Black women with breast cancer are more likely to have triple negative breast cancer than white women with breast cancer.

Many breast cancers have receptors for the hormones oestrogen and progesterone, or less commonly for a protein called HER2. These receptors can stimulate the cancers to grow. After surgery, the tissue that is removed from a woman’s breast is tested for receptors.