Abstract 383: The AdnaCellector, a new fully automated selection for circulating tumor cells in blood of primary and metastatic breast cancer patients

Abstract

Abstract Background: The utility of circulating tumor cells (CTC) as promising prognostic biomarker to predict the risk of relapse in primary and metastatic breast cancer (BC) patients as well as to monitor disease progression has already been shown over the last years. Nevertheless, the clinical utility of CTC highly depends on a robust and standardized selection method which can be easily integrated in clinical routine. To adress this medical need, the AdnaCellector, a fully automated immunomagnetic cell capturing device, was developed to a prototype stage. Here we present a pilot study in a clinical setting to investigate the general assay performance of the AdnaCellector and the overall agreement with the manual AdnaTest BreastCancerSelect. Materials and Methods: In total, CTC were isolated from EDTA blood of 13 primary and 20 metastatic BC patients with the AdnaCellector and the manual AdnaTest BreastCancerSelect (AdnaGen GmbH, Langenhagen, Germany) in duplicates of 5ml. The lysates generated from both selection variants were processed manually with the AdnaTest BreastCancerDetect. Established cDNA was used for multiplex PCR (MUC-1, GA733-2, HER2). Resulting PCR fragments were analyzed with the Agilent Bioanalyzer 2100. Patients were classified as CTC positive if at least one marker was detected with a concentration ≥0.15 ng/μl. Assay positivity among the same patient was evaluated with regard to the selection method. To further estimate the ease of use of both methods a non-experienced trainee was choosen to perform the procedure. Results: Comparing all clinical samples, the detection rate was 32% (20/61) for the manual workflow and 42% (25/60) using the AdnaCellector with an overall concordance of 81% (p<0.001). If samples were separately analyzed for blood from primary or metastatic patients, the manual procedure detected 35% (8/23) positive samples vs 30% (7/23) positivity by the AdnaCellector in primary blood samples and 33% (12/36) vs 50% (18/37) in metastatic blood samples, respectively. The overall concordance was 76% (p = 0.05) in the primary setting and 86% (p<0.001) for the metastatic samples. Discussion: For CTC detection in a clinical setting, we were able to demonstrate a good concordance of the fully automated AdnaCellector prototype and the manual workflow of the AdnaTest BreastCancer. Most interestingly, in the metastatic setting we observed even substantial higher sensitivity vs the manual procedure which may indicate that this automated and, therefore, standardized procedure may provide better test performance if the AdnaTest is used by non-experienced personel. Citation Format: Maren Bredemeier, Natalie Fenjuk, Siegfried Hauch, Bahriye Aktas, Mitra Tewes, Rainer Kimmig, Sabine Kasimir-Bauer. The AdnaCellector, a new fully automated selection for circulating tumor cells in blood of primary and metastatic breast cancer patients. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 383. doi:10.1158/1538-7445.AM2015-383