Abstract 1047: Advanced Lung Adenocarcinoma Cell Bank (ALACB) : A comprehensive preclinical platform
Authors: Kim Seok Young , Kim Dong Hwi , Joo Hyeong-Seok , Lee Ji Yeon , Yun Mi Ran , Kang Han Na , Cho Byoung Chul , Kim Hye Ryun 
Published: August 2018

Abstract
Purpose: Patients with advanced lung adenocarcinoma often lack large clinical specimens required for molecular testing, and are limited in next therapeutic options. Patient-derived cells (PDC) derived from malignant effusion (ME) of the patient can predict patient drug responses and provide a valuable tool for studying mechanisms of drug resistance. In this study, we created an Advanced Lung Adenocarcinoma Cell Bank (ALACB) consisting of 27 unique PDCs established from patients who progressed on various TKIs including osimertinib.
Experimental Design: ME samples were tested for malignancy, processed, observed by light microscopy, and cultured. The establishment of a PDC was considered complete when it was free of normal cells, maintained known patient tumor mutation, and recapitulated patient's response. PDCs were cryopreserved to maintain a cell bank and analyzed by next-generation sequencing before passage number 25.
Results: A total of 110 malignant effusion samples were obtained from 89 patients with advanced lung adenocarcinoma. Sixty-seven patients had EGFR mutations, 9 with ALK rearrangements, 1 with both EGFR mutation and ALK rearrangement, 7 with ROS1 rearrangements, and 5 with unknown driver oncogenes. 62 (56%) samples were positive for tumor. A high correlation between malignancy and spheroid positivity was observed (47/62; 76%). Most PDCs (26/27) were established from malignancy-positive/spheroid-positive samples, 12 of which were serially established from 5 patients along the clinical course. Of 36 cases that were positive for malignancy but failed in the establishment, 27 (75%) were lost due to a paucity of tumor cells, and 8 (22%) lost due to rapid cell senescence before passage number 10. Establishment of ROS1-positive PDCs showed a higher success rate (53%) than PDCs with EGFR-mutations (21%) or ALK rearrangements (23%). Median passage number of all PDCs was 24, while 3 EGFR-mutant PDCs displayed slow growth rates. Of 15 EGFR-mutant PDCs, 7 were derived from gefitinib-resistant tumors, 1 from afatinib-resistant tumor, and 6 from osimertinib or olmutinib-resistant tumors. Three PDCs harbored rare EGFR mutations including exon 20 insertion, L861Q, or G719X/S768I, respectively. Three ALK-positive PDCs were derived from crizotinib-resistant, alectinib-resistant, or ceritinib-resistant tumor. Of 8 ROS1-positive PDCs, 3 were derived from TKI-naïve tumors, and 5 from crizotinib-resistant tumors. Whole-exome sequencing and RNA sequencing were performed on 13 and 6 cases, respectively.
Conclusions: Cytology positivity and spheroid formation were crucial factors in the successful establishment of ALACB, which reflects genomic profiles and drug response of advanced lung adenocarcinoma. ALACB is a renewable resource for biologic assays, generating in vitro drug-resistant models, and evaluation of novel drugs that will advance lung cancer translational research.
Citation Format: Seok Young Kim, Dong Hwi Kim, Hyeong-Seok Joo, Ji Yeon Lee, Mi Ran Yun, Han Na Kang, Byoung Chul Cho, Hye Ryun Kim. Advanced Lung Adenocarcinoma Cell Bank (ALACB) : A comprehensive preclinical platform [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1047.