Author of

• 20158

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  P1.09 - Mesothelioma (ID 695)

  • Event: WCLC 2017
  • Type: Poster Session with Presenters Present
  • Track: Mesothelioma
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/16/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)

  • 22723

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    P1.09-001 - Multiplexed Biomarker Strategies Based on Targeted Proteomics for Detection of Malignant Pleural Mesothelioma in Blood (ID 8811)

    09:30 - 09:30  |  Author(s): M. Choi
    • Abstract

    Background:
    Blood biomarkers are only infrequently used for the diagnosis of malignant pleural mesothelioma. Most of these biomarkers are single marker proteins relying on antibody assays and with limited accuracy for mesothelioma detection in the blood. In our study, we apply targeted proteomics technologies to investigate novel diagnostic strategies based on multiplexed protein biomarkers for mesothelioma detection in serum.
    
    Method:
    We studied more than 400 serum samples of early (I/II) and late stage (III/IV) mesothelioma and asbestos exposed donors collected in USA, Australia and Europe. For quantitative proteomics, 50 µl of serum were processed on 96-well plates over different days to enrich for N-linked glycoproteins based on hydrazide chemistry. After tryptic digestion, serum peptides were analyzed in replicates, separated by ultra-performance liquid chromatography followed by selected reaction monitoring on a triple quadrupole mass spectrometer (LC-SRM). Isotopically labeled peptides were spiked in each sample for quantification and to assess the performance of the LC-SRM platform. Two non-human N-linked glycoproteins were spiked in each serum sample before processing to monitor the performance of the targeted proteomics workflow across samples and plates. The software package MSstats was used for large scale quantitative data analysis.
    
    Result:
    We processed and quantified over 400 serum samples analyzed in LC-SRM replicates. We assessed the performance of the targeted proteomics platform for large scale quantification of a multiplexed six peptide signature (including peptides from the established mesothelin biomarker). The coefficient of variation (CV) for parallel peptide quantification on LC-SRM ranged from 2% to 11.4% with CVs below 8% for all peptides but for one. Based on quantification of the two non-human spiked-in glycoproteins, average standard deviation of the targeted proteomics workflow was 0.42 over all samples. We investigated the performance of the multiplexed six peptide signature in discriminating mesothelioma from asbestos exposed donors. For the signature we fit a multiple logistic regression model on a training set of 212 patients and a validation set of 193 mesothelioma and asbestos exposed donors. The multiplexed biomarker signature discriminated mesothelioma from asbestos exposed with AUC of 0.72 in the validation set. Here, compared with performance of the single marker mesothelin (assessed by LC-SRM), the multiplexed biomarker signature separated early stage mesothelioma from asbestos exposed with AUC of 0.74, with sensitivity of 37.8% at 90% specificity, whereas the single mesothelin peptide had AUC of 0.66 and sensitivity of 22.2%.
    
    Conclusion:
    Multiplexed biomarker strategies based on targeted proteomics technologies can improve mesothelioma diagnosis in blood samples.