Potential red-flag identification of colorectal adenomas with wide-field fluorescence molecular endoscopy

Adenoma miss rates in colonoscopy are unacceptably high, especially for sessile serrated adenomas / polyps (SSA/Ps) and in high-risk populations, such as patients with Lynch syndrome. Detection rates may be improved by fluorescence molecular endoscopy (FME), which allows morphological visualization of lesions with high-definition white-light imaging as well as fluorescence-guided identification of lesions with a specific molecular marker. In a clinical proof-of-principal study, we investigated FME for colorectal adenoma detection, using a fluorescently labelled antibody (bevacizumab-800CW) against vascular endothelial growth factor A (VEGFA), which is highly upregulated in colorectal adenomas. Methods: Patients with familial adenomatous polyposis (n = 17), received an intravenous injection with 4.5, 10 or 25 mg of bevacizumab-800CW. Three days later, they received NIR-FME. Results: VEGFA-targeted NIR-FME detected colorectal adenomas at all doses. Best results were achieved in the highest (25 mg) cohort, which even detected small adenomas ( < 3 mm). Spectroscopy analyses of freshly excised specimen demonstrated the highest adenoma-to-normal ratio of 1.84 for the 25 mg cohort, with a calculated median tracer concentration in adenomas of 6.43 nmol/mL. Ex vivo signal analyses demonstrated NIR fluorescence within the dysplastic areas of the adenomas. Conclusion: These results suggest that NIR-FME is clinically feasible as a real-time, red-flag technique for detection of colorectal adenomas

Implementation and benchmarking of a novel analytical framework to clinically evaluate tumor-specific fluorescent tracers

During the last decade, the emerging field of molecular fluorescence imaging has led to the development of tumor-specific fluorescent tracers and an increase in early-phase clinical trials without having consensus on a standard methodology for evaluating an optical tracer. By combining multiple complementary state-of-the-art clinical optical imaging techniques, we propose a novel analytical framework for the clinical translation and evaluation of tumor-targeted fluorescent tracers for molecular fluorescence imaging which can be used for a range of tumor types and with different optical tracers. Here we report the implementation of this analytical framework and demonstrate the tumor-specific targeting of escalating doses of the near-infrared fluorescent tracer bevacizumab-800CW on a macroscopic and microscopic level. We subsequently demonstrate an 88% increase in the intraoperative detection rate of tumor-involved margins in primary breast cancer patients, indicating the clinical feasibility and support of future studies to evaluate the definitive clinical impact of fluorescence-guided surgery

Potential red-flag identification of colorectal adenomas with wide-field fluorescence molecular endoscopy.

Adenoma miss rates in colonoscopy are unacceptably high, especially for sessile serrated adenomas / polyps (SSA/Ps) and in high-risk populations, such as patients with Lynch syndrome. Detection rates may be improved by fluorescence molecular endoscopy (FME), which allows morphological visualization of lesions with high-definition white-light imaging as well as fluorescence-guided identification of lesions with a specific molecular marker. In a clinical proof-of-principal study, we investigated FME for colorectal adenoma detection, using a fluorescently labelled antibody (bevacizumab-800CW) against vascular endothelial growth factor A (VEGFA), which is highly upregulated in colorectal adenomas.Patients with familial adenomatous polyposis (n = 17), received an intravenous injection with 4.5, 10 or 25 mg of bevacizumab-800CW. Three days later, they received NIR-FME.VEGFA-targeted NIR-FME detected colorectal adenomas at all doses. Best results were achieved in the highest (25 mg) cohort, which even detected small adenomas (&lt;3 mm). Spectroscopy analyses of freshly excised specimen demonstrated the highest adenoma-to-normal ratio of 1.84 for the 25 mg cohort, with a calculated median tracer concentration in adenomas of 6.43 nmol/mL.signal analyses demonstrated NIR fluorescence within the dysplastic areas of the adenomas.These results suggest that NIR-FME is clinically feasible as a real-time, red-flag technique for detection of colorectal adenomas

The Tetraspanin CD37 Orchestrates the alpha4beta1 Integrin-Akt Signaling Axis and Supports Long-Lived Plasma Cell Survival

Contains fulltext : 109748.pdf (publisher's version ) (Closed access)Signaling by the serine and threonine kinase Akt (also known as protein kinase B), a pathway that is common to all eukaryotic cells, is central to cell survival, proliferation, and gene induction. We sought to elucidate the mechanisms underlying regulation of the kinase activity of Akt in the immune system. We found that the four-transmembrane protein CD37 was essential for B cell survival and long-lived protective immunity. CD37-deficient (Cd37(-/-)) mice had reduced numbers of immunoglobulin G (IgG)-secreting plasma cells in lymphoid organs compared to those in wild-type mice, which we attributed to increased apoptosis of plasma cells in the germinal centers of the spleen, areas in which B cells proliferate and are selected. CD37 was required for the survival of IgG-secreting plasma cells in response to binding of vascular cell adhesion molecule 1 to the alpha(4)beta(1) integrin. Impaired alpha(4)beta(1) integrin-dependent Akt signaling in Cd37(-/-) IgG-secreting plasma cells was the underlying cause responsible for impaired cell survival. CD37 was required for the mobility and clustering of alpha(4)beta(1) integrins in the plasma membrane, thus regulating the membrane distribution of alpha(4)beta(1) integrin necessary for activation of the Akt survival pathway in the immune system

Tumor-specific uptake of fluorescent bevacizumab-IRDye800CW microdosing in patients with primary breast cancer: A phase I feasibility study.

Purpose: to provide proof of principle of safety, breast tumor-specific uptake and positive tumor margin assessment of the systemically administered near-infrared fluorescent (NIRF) tracer bevacizumab-IRDye800CW targeting vascular endothelial growth factor (VEGF)-A in breast cancer patients. Experimental Design: Twenty patients with primary invasive breast cancer eligible for primary surgery received 4.5 mg bevacizumab-IRDye800CW as intravenous bolus injection. Safety aspects were assessed as well as tracer uptake and tumor delineation during surgery and ex vivo in surgical specimens using an optical imaging system. Ex vivo multiplexed histopathology analyses were performed for evaluation of biodistribution of tracer uptake and co-registration of tumor tissue and healthy tissue. Results: None of the patients experienced adverse events. Tracer levels in primary tumor tissue were higher compared to those in the tumor margin (P &lt; 0.05) and healthy tissue (P &lt; 0.0001). VEGF-A tumor levels also correlated with tracer levels (r = 0.63, P &lt; 0.0002). All but one tumor showed specific tracer uptake. Two out of 20 surgically excised lumps contained microscopic positive margins detected ex vivo by fluorescent macro- and microscopy and confirmed at the cellular level. Conclusions: Our study shows that systemic administration of the bevacizumab-IRDye800CW tracer is safe for breast cancer guidance and confirms tumor and tumor-margin uptake as evaluated by a systematic validation methodology. The findings are a step towards a phase II dose-finding study aimed at in vivo margin assessment and point to a novel drug assessment tool that provides a detailed picture of drug distribution in tumor tissue