Neoadjuvant Bevacizumab Improves pCR In HER2-Negative Early Breast Cancer

Complete pathological response rate is boosted by neoadjuvant bevacizumab in HER2-negative early-stage breast cancer patients

medwireNews: ARTemis trial results indicate that bevacizumab significantly improves the likelihood of a complete pathological response (pCR) in patients receiving chemotherapy for HER2-negative early breast cancer.

However, Helena Earl, from the University of Cambridge in the UK, and co-authors caution that “whether the improvement in pathological complete response will lead to improved disease-free and overall survival outcomes is unknown and will be reported after longer follow-up.”

“Meta-analysis of available neoadjuvant trials is likely to be the only way to define subgroups of early breast cancer that would have clinically significant long-term benefit from bevacizumab treatment”, they write in The Lancet Oncology.

A pCR was achieved by 22% of the 388 patients who were randomly assigned to receive bevacizumab alongside a regimen of docetaxel followed by fluorouracil, epirubicin and cyclophosphamide, compared with just 17% of the 393 patients given chemotherapy alone.

The likelihood of a pCR in the open-label phase III trial was also significantly associated with Oestrogen receptor (ER) status and tumour grade, the team states. A pCR was reported for 38% of ER-negative patients and 41% of those with a weak positive result versus 7% of patients with a strong positive result. And just 7% of patients with a grade 1 or 2 tumour had a pCR compared with 29% of those with grade 3 disease.

Moreover, bevacizumab appeared to increase the likelihood of a pCR in patients who were ER-negative or weakly ER-positive and those with grade 3 disease, whereas strongly ER-positive and grade 1 or 2 patients derived no such benefit, the researchers report.

While the ARTemis trial results are in line with three other studies indicating that neoadjuvant bevacizumab improves pCR in this patient population, differences have been found in which patient subgroups respond best. Differences in the definition of ER status could explain why one study found that ER-positive patients had the highest pCR, Helena Earl et al suggest.

Fabrice Andre, from Gustave Roussy in Villejuif, France, and co-authors of an accompanying comment therefore recommend a meta-analysis of data from the four neoadjuvant trials to improve understanding of ER status interaction, patient survival outcomes and the optimal chemotherapy regimen for use with bevacizumab.

Neoadjuvant trials could also identify a Biomarker for bevacizumab response and elucidate further on the agent’s mechanism, they add.

References

Earl HM, Hiller L, Dunn JA, et al. Efficacy of neoadjuvant bevacizumab added to docetaxel followed by fluorouracil, epirubicin, and cyclophosphamide, for women with HER2-negative early breast cancer (ARTemis): an open-label, randomised, phase 3 trial. Lancet Oncol 2015; Advance online publication 12 May. DOI: http://dx.doi.org/10.1016/S1470-2045(15)70137-3

Andre F, Deluche E, Bonnefoi H. Bevacizumab: the phoenix of breast oncology?Lancet Oncol 2015; Advance online publication 12 May. DOI: http://dx.doi.org/10.1016/S1470-2045(15)70201-9

medwireNews (www.medwireNews.com) is an independent medical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2015