Discrete microfluidics for the isolation of circulating tumor cell subpopulations targeting fibroblast activation protein alpha and epithelial cell adhesion molecule.

Circulating tumor cells consist of phenotypically distinct subpopulations that originate from the tumor microenvironment. We report a circulating tumor cell dual selection assay that uses discrete microfluidics to select circulating tumor cell subpopulations from a single blood sample; circulating tumor cells expressing the established marker epithelial cell adhesion molecule and a new marker, fibroblast activation protein alpha, were evaluated. Both circulating tumor cell subpopulations were detected in metastatic ovarian, colorectal, prostate, breast, and pancreatic cancer patients and 90% of the isolated circulating tumor cells did not co-express both antigens. Clinical sensitivities of 100% showed substantial improvement compared to epithelial cell adhesion molecule selection alone. Owing to high purity (>80%) of the selected circulating tumor cells, molecular analysis of both circulating tumor cell subpopulations was carried out in bulk, including next generation sequencing, mutation analysis, and gene expression. Results suggested fibroblast activation protein alpha and epithelial cell adhesion molecule circulating tumor cells are distinct subpopulations and the use of these in concert can provide information needed to navigate through cancer disease management challenges.

Adrenocortical carcinoma: modern management and evolving treatment strategies.

Adrenocortical carcinoma (ACC) is a rare cancer with a poor prognosis. Unlike many other cancers, there has been little improvement in patient outcome over the past several decades. However, as scientific advancements are made and our understanding of the molecular genetics involved in ACC improve then progress may be achieved in this devastating disease. This review focuses on recent literature published in the field of ACC from 2010 to 2015 with an emphasis on improving diagnosis, staging and treatment for ACC.

Pheochromocytoma Screening Initiation and Frequency in von Hippel-Lindau Syndrome.

CONTEXT: Patients with von Hippel-Lindau (VHL) syndrome have a 25-30% chance of developing pheochromocytoma. Although practice guidelines recommend biochemical and radiological screening every 1-2 years for pheochromocytoma in patients with VHL, there are limited data on the optimal age and frequency for screening. OBJECTIVE: Our objective was to determine the earliest age of onset and frequency of contralateral and recurrent pheochromocytomas in patients with VHL syndrome. METHODS: This is a retrospective analysis of a prospective cohort of patients with VHL enrolled in a natural history study. RESULTS: A total of 273 patients diagnosed with VHL were enrolled in a natural history clinical study. Thirty-one percent (84) were diagnosed with pheochromocytoma. The mean age of diagnosis was 28.8 ± 13.9 years. The earliest age at diagnosis was 5.5 years. Median follow-up for the cohort was 116.6 months (range, 0.1-613.2). Ninety-nine percent (83) of patients underwent adrenalectomy. Fifty-eight and 32% of patients had metanephrines and/or catecholamines elevated more than two times and more than four times the upper limit of normal, respectively. Twenty-five percent (21) of pheochromocytomas were diagnosed in pediatric patients younger than 19 years of age, and 86% and 57% of pediatric patients had an elevation more than two times and more than four times upper limit of normal, respectively. Eight patients had a total of nine recurrences. The median age at recurrence was 33.5 years (range, 8.8-51.9). Recurrences occurred as short as 0.5 years and as long as 39.7 years after the initial operation. CONCLUSIONS: Our findings among VHL pediatric patients supports the need for biochemical screening starting at age 5 with annual lifelong screening.

UV activation of polymeric high aspect ratio microstructures: ramifications in antibody surface loading for circulating tumor cell selection.

The need to activate thermoplastic surfaces using robust and efficient methods has been driven by the fact that replication techniques can be used to produce microfluidic devices in a high production mode and at low cost, making polymer microfluidics invaluable for in vitro diagnostics, such as circulating tumor cell (CTC) analysis, where device disposability is critical to mitigate artifacts associated with sample carryover. Modifying the surface chemistry of thermoplastic devices through activation techniques can be used to increase the wettability of the surface or to produce functional scaffolds to allow for the covalent attachment of biologics, such as antibodies for CTC recognition. Extensive surface characterization tools were used to investigate UV activation of various surfaces to produce uniform and high surface coverage of functional groups, such as carboxylic acids in microchannels of different aspect ratios. We found that the efficiency of the UV activation process is highly dependent on the microchannel aspect ratio and the identity of the thermoplastic substrate. Colorimetric assays and fluorescence imaging of UV-activated microchannels following EDC/NHS coupling of Cy3-labeled oligonucleotides indicated that UV-activation of a PMMA microchannel with an aspect ratio of ~3 was significantly less efficient toward the bottom of the channel compared to the upper sections. This effect was a consequence of the bulk polymer's damping of the modifying UV radiation due to absorption artifacts. In contrast, this effect was less pronounced for COC. Moreover, we observed that after thermal fusion bonding of the device's cover plate to the substrate, many of the generated functional groups buried into the bulk rendering them inaccessible. The propensity of this surface reorganization was found to be higher for PMMA compared to COC. As an example of the effects of material and microchannel aspect ratios on device functionality, thermoplastic devices for the selection of CTCs from whole blood were evaluated, which required the immobilization of monoclonal antibodies to channel walls. From our results, we concluded the CTC yield and purity of isolated CTCs were dependent on the substrate material with COC producing the highest clinical yields for CTCs as well as better purities compared to PMMA.

Emerging therapy for adrenocortical carcinoma.

Adrenocortical carcinoma (ACC) is a very rare and aggressive tumor with dismal outcomes. Best current treatments include complete surgical resection for localized resectable disease and systemic therapy with mitotane alone or in combination for advanced ACC. Advances in molecular genetic profiling of ACC have created multiple new targets for potential treatment options in ACC. This article reviews the current treatment options available for ACC and discusses the potential new targets identified through molecular profiling.