Oops, you're using an old version of your browser so some of the features on this page may not be displaying properly.

MINIMAL Requirements: Google Chrome 24+Mozilla Firefox 20+Internet Explorer 11Opera 15–18Apple Safari 7SeaMonkey 2.15-2.23

Cocktail & Poster Display session

93P - Circulating cell-free DNA fragmentation profiles during systemic therapy of advanced-stage non-small cell lung cancer patients


06 Mar 2023


Cocktail & Poster Display session


Jelena Milovanovic


Annals of Oncology (2023) 8 (1suppl_2): 100898-100898. 10.1016/esmoop/esmoop100898


J. Milovanovic1, I. Boljevic1, J. Spasic2, M. Topalovic1, A. Krivokuca3, M. Cavic1, M. Tanic4

Author affiliations

  • 1 Experimental Oncology Department, Institute for Oncology and Radiology of Serbia, 11000 - Belgrade/RS
  • 2 Clinic For Medical Oncology, Institute for Oncology and Radiology of Serbia, 11000 - Belgrade/RS
  • 3 Genetic Counseling For Hereditary Cancers, Institute for Oncology and Radiology of Serbia, 11000 - Belgrade/RS
  • 4 Experimental Oncology Dept., Institute for Oncology and Radiology of Serbia, 11000 - Belgrade/RS


This content is available to ESMO members and event participants.

Abstract 93P


Circulating cell-free DNA (cfDNA) may be used for monitoring response to systemic treatment in patients with advanced carcinomas. Tumor-derived cfDNA is characterized by a shift of fragment sizes. The aim of the study was to evaluate longitudinally the changes in cfDNA fragmentation profile and correlate it with disease progression in non-small cell lung cancer (NSCLC) patients receiving anticancer systemic therapy.


We recruited 14 patients aged 36 - 72 years at diagnosis with advanced stage IIIb/IV NSCLC and performance status 0-2 at diagnosis. All patients were initially tested on PD-L1 expression as well as on mutations in the EGFR and the ALK genes. Patients with positive PD-L1 expression (n=3) received immunotherapy pembrolizumab as the first-line therapy, those with mutations in the EGFR gene (n=3) received tyrosine kinase inhibitor - gefitinib, one ALK-positive patient received alectinib, while other patients received standard chemotherapy - Carboplatin/Etoposide (n=3) or Carboplatin/Paclitaxel (n=4). Consecutive plasma samples were collected at diagnosis, during systemic treatment and after termination of the therapy. cfDNA was extracted from 0.5 mL of plasma using magnetic-based MagMax cfDNA extraction kit, and quantified using Qubit HS dsDNA assay and ddPCR. Contamination with genomic DNA was determined using a B-cell-specific ddPCR assay. Fragment size distribution of cfDNA was determined by Agilent Bioanalyzer HS dsDNA assay.


Concentrations of cfDNA measured by Qubit (∼14.3 ng/mL of plasma) showed good correlation to the absolute quantification determined by ddPCR (∼13.22 ng/mL of plasma). In a 38% of samples there was small contamination by peripheral blood cells gDNA. Besides expected fraction of cfDNA (168 bp mode) observed in all samples, we observed in 48% of samples an ultra-short fraction of cfDNA (50bp mode).


Application of magnetic-based cfDNA extraction method allowed us to detect an ultra-short cfDNA fraction, previously unrecognized in lung cancer patients. Studies to correlate it to progression-free survival are ongoing.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Institute for Oncology and Radiology of Serbia.


The Science Fund of the Republic of Serbia (PROMIS/2020/6060876).


All authors have declared no conflicts of interest.

This site uses cookies. Some of these cookies are essential, while others help us improve your experience by providing insights into how the site is being used.

For more detailed information on the cookies we use, please check our Privacy Policy.

Customise settings
  • Necessary cookies enable core functionality. The website cannot function properly without these cookies, and you can only disable them by changing your browser preferences.