Purpose: Extensive work in preclinical models has shown that microenvironmental cells influence many aspects of cancer cell behavior, including metastatic potential and their sensitivity to... Show morePurpose: Extensive work in preclinical models has shown that microenvironmental cells influence many aspects of cancer cell behavior, including metastatic potential and their sensitivity to therapeutics. In the human setting, this behavior is mainly correlated with the presence of immune cells. Here, in addition to T cells, B cells, macrophages, and mast cells, we identified the relevance of nonimmune cell types for breast cancer survival and therapy benefit, including fibroblasts, myoepithelial cells, muscle cells, endothelial cells, and seven distinct epithelial cell types.Experimental Design: Using single-cell sequencing data, we generated reference profiles for all these cell types. We used these reference profiles in deconvolution algorithms to optimally detangle the cellular composition of more than 3,500 primary breast tumors of patients that were enrolled in the SCAN-B and MATADOR clinical trials, and for which bulk mRNA sequencing data were available.Results: This large data set enables us to identify and subsequently validate the cellular composition of miaoenvironments that distinguish differential survival and treatment benefit for different treatment regimens in patients with primary breast cancer. In addition to immune cells, we have identified that survival and therapy benefit are characterized by various contributions of distinct epithelial cell types.Conclusions: From our study, we conclude that differential survival and therapy benefit of patients with breast cancer are characterized by distinct microenvironments that include specific populations of immune and epithelial cells. Show less
Background: The addition of bevacizumab to chemotherapy conferred a modest progression-free survival (PFS) benefit in metastatic triple-negative breast cancer (mTNBC). However, no overall survival ... Show moreBackground: The addition of bevacizumab to chemotherapy conferred a modest progression-free survival (PFS) benefit in metastatic triple-negative breast cancer (mTNBC). However, no overall survival (OS) benefit has been reported. Also, its combination with carboplatin-cyclophosphamide (CC) has never been investigated. Methods: The Triple-B study is a multicenter, randomized phase IIb trial that aims to prospectively validate predictive biomarkers, including baseline plasma vascular endothelial growth factor receptor-2 (pVEGFR-2), for bevacizumab benefit. mTNBC patients were randomized between CC and paclitaxel (P) without or with bevacizumab (CC +/- B or P +/- B). Here we report on a preplanned safety and preliminary efficacy analysis after the first 12 patients had been treated with CC+B and on the predictive value of pVEGFR-2. Results: In 58 patients, the median follow-up was 22.1 months. Toxicity was manageable and consistent with what was known for each agent separately. There was a trend toward a prolonged PFS with bevacizumab compared to chemotherapy only (7.0 vs. 5.2 months; adjusted HR = 0.60; 95% CI 0.33-1.08; p = 0.09), but there was no effect on OS. In this small study, pVEGFR-2 concentration did not predict a bevacizumab PFS benefit. Both the intention-to-treat analysis and the per-protocol analysis did not yield a significant treatment-by-biomarker test for interaction (p(interaction) = 0.69). Conclusions:CC and CC+B are safe first-line regimens for mTNBC and the side effects are consistent with those known for each individual agent. pVEGFR-2 concentration did not predict a bevacizumab PFS benefit. Show less
Rossum, A.G.J. van; Kok, M.; Werkhoven, E. van; Opdam, M.; Mandjes, I.A.M.; Leeuwen-Stok, A.E. van; ... ; MATADOR Trialists' Grp 2018