Introduction. This study compared the diagnostic test accuracy of magnetic resonance imaging (MRI) with that of 18 F-fluoro-2-glucose-positron emission tomography/ computed tomography (FDG-PET/CT) imaging in assessment of response to neoadjuvant chemotherapy (NAC) in breast cancer. Methods. A systematic search was performed in PubMed and EMBASE (last updated in June 2015). Studies investigating the performance of MRI and FDG-PET or FDG-PET/CT imaging during or after completion of NAC in patients with histologically proven breast cancer were eligible for inclusion. We considered only studies reporting a direct comparison between these imaging modalities to establish precise summary estimates in the same setting of patients. Pathologic response was considered as the reference standard. Two authors independently screened and selected studies that met the inclusion criteria and extracted the data.

Vascular endothelial cells (ECs) are responsible for post-ischemic angiogenesis, a process that is regulated by reactive oxygen species. Recent studies indicate that endothelial Nox4 based NADPH oxidase may have a key role. This study examines the role of endothelial Nox4 in ischemia-induced angiogenesis and explores the potential mechanisms involved. Mouse lines overexpressing human Nox4 wild type (EWT) or its dominant negative form P437H (EDN) specifically in the endothelium were used. Non-transgenic littermate mice (NTg) were used as controls. Following hind limb ischemia, blood flow recovery was enhanced in EWT and was impaired in EDN compared with NTg. The critical angiogenesis regulating genes vascular endothelial growth factor receptor2 (VEGFR2), endothelial nitric oxide synthase (eNOS) and transforming growth factor beta1 (TGFbeta1) were upregulated in EWT both in the ischemic muscle and in heart ECs, while TGFbeta1 was downregulated in EDNECs. In EC, both VEGFA and TGFbeta1 stimulated EC proliferation, migration, and capillary-like network formation in EWT but failed to do so in EDN. Application of TGFbeta1 increased both VEGFR2 and eNOS expression levels,whereas blocking TGFbeta1 or addition of catalase inhibited the phosphorylation of VEGFR2 and eNOS, indicating H2O2 and TGFbeta1 signaling downstream of Nox4 is critical to maintain EC angiogenic functions. Use of cell specific transgenic mice with both upregulation and downregulation of endothelial Nox4 indicate several mechanisms linked to Nox4 play a role in angiogenesis. Endothelial Nox4 regulates ischemia-induced angiogenesis, likely through H2O2- and TGFbeta1-mediated activation of cell signaling pathways essential for endothelial function.

FDG PET/CT is a valuable imaging modality that impacts the clinical management of patients with CRC and those with anal cancer.

Angiogenesis is a critical component of breast cancer development, and identification of imaging-based angiogenesis assays has prognostic and treatment implications. We evaluated the association of semi-quantitative kinetic and radiomic breast cancer features on dynamic contrast-enhanced (DCE)-MRI with microvessel density (MVD), a marker for angiogenesis. Invasive breast cancer kinetic features (initial peak percent enhancement [PE], signal enhancement ratio [SER], functional tumor volume [FTV], and washout fraction [WF]), radiomics features (108 total features reflecting tumor morphology, signal intensity, and texture), and MVD (by histologic CD31 immunostaining) were measured in 27 patients (1/2016–7/2017). Lesions with high MVD levels demonstrated higher peak SER than lesions with low MVD (mean: 1.94 vs. 1.61, area under the receiver operating characteristic curve [AUC] = 0.79, p = 0.009) and higher WF (mean: 50.6% vs. 22.5%, AUC = 0.87, p = 0.001). Several radiomics texture features were also promising for predicting increased MVD (maximum AUC = 0.84, p = 0.002). Our study suggests DCE-MRI can non-invasively assess breast cancer angiogenesis, which could stratify biology and optimize treatments.