3PD - Liquid biopsy in patients with adenocarcinoma of the lung and its correlation with their tumor tissue molecular profile

Date 15 April 2016
Event European Lung Cancer Conference 2016 (ELCC) 2016
Session Biomarkers
Topics Lung and other Thoracic Tumours
Pathology/Molecular Biology
Translational Research
Presenter Edgardo Santos
Citation Journal of Thoracic Oncology (2016) 11 (supplement 4): S57-S166. S1556-0864(16)X0004-4
Authors E.S. Santos1, L. Raez2, L.D.C. Castillero3, C. Marana2, B. Hunis2
  • 1Medicine-oncology, Eugene M. & Christine E. Lynn Cancer Institute, 33486 - Boca Raton/US
  • 2Hematology/oncology, Memorial West Cancer Institute, 33028 - Pembroke Pines/US
  • 3School Of Medicine, Universidad Nacional de Panama, Panama/PA

Abstract

Background

Adequate quantity of tumor tissue for molecular analysis is a major handicap to deliver personalized medicine. Reasons such as difficulty to perform tumor biopsy (TBX) either because of tumor location, patient's co-morbid conditions or the fact we need to repeat the TBX are among the common factors for lack of molecular profiling results (MPR). Hence, liquid biopsy (LBX) has emerged as a potential alternative to detect these genomic alterations.

Methods

We analyzed 59 patients with stage IV or recurrent adenocarcinoma of the lung (ADENO) using Guardant 360 test; sample collections were done at Lynn Cancer Institute and Memorial Cancer Institute. Alterations detected by this test include single nucleotide variations, amplifications, ALK, FGFR2, FGFR3, RET, ROS1, NTRK1 genes, and short insertions/duplications/deletions in exons 19 and 20 of the EGFR and ERBB2 genes as well as exon 14 skipping of the MET gene. We compared these results with their tumor tissue MPR in each individual, to assess their correlation.

Results

41/59 pts were females; median age 75 (range, 27–99). 44 pts (75%) had at least 1 genomic alteration by LBX (range, 1–10). Most common abnormalities found in LBX: EGFR (20 pts), TP53 (19 pts), and NF1 (11 pts). From this 44 pts with + LBX results, 29 pts (66%) had tumor tissue MPRs for comparison. Major reason for lack of tumor tissue MPRs: insufficient tumor (11/17; 65%). For comparison between the 2 modalities, we considered all pts with available results in both tests (n = 42 pts); 20 pts (48%) had at least 1 genomic abnormality or no abnormality identify in both type of “biopsies”. Most of the concordance was in EGFR mutations; LBX caught 12/17 (71%) EGFR mutations in TBX. Nonetheless, LBX caught 11 EGFR alterations not present or available by TBX MPR.

Conclusions

Insufficient amount of tumor is the reason for lacking tumor MPRs. LBX offers an alternative/complementary way to identify genomic alterations in a much easy way. Our cohort had 48% concordance between LBX and TBX; however, for EGFR mutation, correlation was higher (71%). Discrepancies between both modalities could be explained by timing when samples were taken and tumor heterogeneity. Updated data with 90 pts will be presented at the meeting.

Clinical trial identification

NA

Legal entity responsible for the study

Lynn Cancer Institute Research Department

Funding

Lynn Cancer Institute Research Department

Disclosure

L. Raez, B. Hunis: Research support: Liquid Genomics; Exosomes. All other authors have declared no conflicts of interest.