Circulating tumor cells reveal early predictors of disease progression in patients with stage III NSCLC undergoing chemoradiation and immunotherapy

Circulating tumor cells (CTCs) are early signs of metastasis and can be used to monitor disease progression well before radiological detection by imaging. Using an ultrasensitive graphene oxide microfluidic chip nanotechnology built with graphene oxide sheets, we were able to demonstrate that CTCs can be specifically isolated and molecularly characterized to predict future progression in patients with stage III non-small cell lung cancer (NSCLC). We analyzed CTCs from 26 patients at six time points throughout the treatment course of chemoradiation followed by immune checkpoint inhibitor immunotherapy. We observed that CTCs decreased significantly during treatment, where a larger decrease in CTCs predicted a significantly longer progression-free survival time. Durvalumab-treated patients who have future progression were observed to have sustained higher programmed death ligand 1+ CTCs compared to stable patients. Gene expression profiling revealed phenotypically aggressive CTCs during chemoradiation. By using emerging innovative bioengineering approaches, we successfully show that CTCs are potential biomarkers to monitor and predict patient outcomes in patients with stage III NSCLC.

Abstract B37: Analysis of non-small cell lung cancer (NSCLC) circulating biomarkers for monitoring early response to radiation therapy

Approximately 20% of non-small cell lung cancer (NSCLC) patients will be diagnosed with stage 3 cancer, with a predicted survival rate between 20-30%. Stage 3 NSCLC patients commonly undergo chemoradiation treatment, with imaging scans being the standard of care for determining tumor control or progression both during and after radiation treatment. Imaging technologies can only show progression after it has occurred, making treatment challenging. We suggest that the molecular characterization of biomarkers found in the bloodstream can identify or predict radiation treatment efficacy before progression becomes visible on a scan. In this study, patients undergo a response-driven adaptive radiation therapy (RDART) protocol: four weeks of chemoradiation followed by a set of imaging scans before an additional 2 weeks of adapted, personalized radiation with chemotherapy. In this work, we provide combined analysis of both circulating tumor cells (CTCs), a rare cell found in a patient’s peripheral blood, and exosomes, nanovesicles excreted from cells, for use in assessing radiation efficacy. Our initial cohort is 30 patients, and we aimed to collect six timepoints: one pretreatment, two during radiation treatment, and three after radiation treatment. In this study, we look at the changes in several characteristics: CTC counts, PD-L1 expression on CTCs, as well as gene expression changes of both CTCs and exosomes using Affymetrix microarrays. CTCs were isolated using a graphene oxide (GO)-based microfluidic device and were found to be present in all pretreatment samples and most following samples. Initial transcriptome profiling of 5 patients using microarrays highlighted clustered gene expression differences for both CTCs and exosomes when comparing pretreatment samples with those collected during radiation.

Citation Format: Emma Purcell, Zeqi Niu, Madeline Grzesik, Sarah Owen, Heather Fairbairn, Shruti Jolly, Sunitha Nagrath. Analysis of non-small cell lung cancer (NSCLC) circulating biomarkers for monitoring early response to radiation therapy [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr B37.

[Changes in the sodium, potassium and lithium ion concentration in human epidermis in relation to death]

The concentrations of Na+, K+, Li+ have been assayed in the epidermis samples from 58 cadavers and 20 healthy individuals. The samples have been taken from the heels, and assayed with 2 flame photometers (Corning 480), using standard solutions supplied by the manufacturer. A concentration of Na+ and K+ in men exceeded the levels of these ions in women by two-fold. A level of Li+ is the same in both sexes and amounts to 2.8 mEq/kg. The Na+:K+ ratio in the epidermis of women and men is about 4:1. In the samples collected from cadavers, the difference in Na+ and K+ levels has been lower but Li+ level has been higher, amounting to 4.3 mEq/kg.