Exosomal lipids for classifying early and late stage non-small cell lung cancer

• Published in: Analytica chimica acta Vol. 1037; pp. 256 - 264
• Main Authors: Fan, Teresa W.M., Zhang, Xiaofei, Wang, Chi, Yang, Ye, Kang, Woo-Young, Arnold, Susanne, Higashi, Richard M., Liu, Jinze, Lane, Andrew N.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 11.12.2018; Elsevier BV
• Subjects: Adult; Aged; Aged, 80 and over; Atrophy; Biomarkers; Blood plasma; Cancer; Carcinoma, Non-Small-Cell Lung - blood; Carcinoma, Non-Small-Cell Lung - diagnosis; Classification; Data processing; Exosomal lipid profiling; Exosomes; Exosomes - chemistry; Female; Fourier transforms; Health risks; Humans; Immunomodulation; LASSO; Lipids; Lipids - blood; Lung cancer; Lung Neoplasms - blood; Lung Neoplasms - diagnosis; Male; Mass Spectrometry; Mass spectroscopy; Medical screening; Metabolomics; Middle Aged; Multivariate Analysis; Neoplasm Staging; Non-small cell lung cancer; Non-small cell lung carcinoma; Random forest; Statistical methods; Surgery; Tumors; Ultrahigh resolution Fourier transform mass spectrometry; Exosomal lipid profiling; NSCLC; Non-small cell lung cancer; LASSO; OPLS-DA; AUROC; Ultrahigh resolution Fourier transform mass spectrometry; Random forest; UHR-FTMS; PCA
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2018.02.051

Lung cancer is the leading cause of cancer deaths in the United States. Patients with early stage lung cancer have the best prognosis with surgical removal of the tumor, but the disease is often asymptomatic until advanced disease develops, and there are no effective blood-based screening methods for early detection of lung cancer in at-risk populations. We have explored the lipid profiles of blood plasma exosomes using ultra high-resolution Fourier transform mass spectrometry (UHR-FTMS) for early detection of the prevalent non-small cell lung cancers (NSCLC). Exosomes are nanovehicles released by various cells and tumor tissues to elicit important biofunctions such as immune modulation and tumor development. Plasma exosomal lipid profiles were acquired from 39 normal and 91 NSCLC subjects (44 early stage and 47 late stage). We have applied two multivariate statistical methods, Random Forest (RF) and Least Absolute Shrinkage and Selection Operator (LASSO) to classify the data. For the RF method, the Gini importance of the assigned lipids was calculated to select 16 lipids with top importance. Using the LASSO method, 7 features were selected based on a grouped LASSO penalty. The Area Under the Receiver Operating Characteristic curve for early and late stage cancer versus normal subjects using the selected lipid features was 0.85 and 0.88 for RF and 0.79 and 0.77 for LASSO, respectively. These results show the value of RF and LASSO for metabolomics data-based biomarker development, which provide robust an independent classifiers with sparse data sets. Application of LASSO and Random Forests identifies lipid features that successfully distinguish early stage lung cancer patient from healthy individuals. [Display omitted]