Fine needle aspirate flow cytometric phenotyping characterizes immunosuppressive nature of the mesothelioma microenvironment

Our plain-English summary of Fine needle aspirate flow cytometric phenotyping characterizes immunosuppressive nature of the mesothelioma microenvironment, by P.H. Lizotte, R.E. Jones, L. Keogh, et al (Scientific Reports, 2016).

The study

• Authors: P.H. Lizotte, R.E. Jones, L. Keogh, E. Ivanova, H. Liu, M.M. Awad, P.S. Hammerman, R.R. Gill, W.G. Richards, D.A. Barbie, A.J. Bass, R. Bueno, J.M. English, M. Bittinger, K.K. Wong
• Journal: Scientific Reports
• Published: 2016;6:31745
• Cited by: 22 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

With the emergence of checkpoint blockade and other immunotherapeutic drugs, and the growing adoption of smaller, more flexible adaptive clinical trial designs, there is an unmet need to develop diagnostics that can rapidly immunophenotype patient tumors. The ability to longitudinally profile the tumor immune infiltrate in response to immunotherapy also presents a window of opportunity to illuminate mechanisms of resistance. We have developed a fine needle aspirate biopsy (FNA) platform to perform immune profiling on thoracic malignancies. Matching peripheral blood, bulk resected tumor, and FNA were analyzed from 13 mesothelioma patients. FNA samples yielded greater numbers of viable cells when compared to core needle biopsies. Cell numbers were adequate to perform flow cytometric analyses on T cell lineage, T cell activation and inhibitory receptor expression, and myeloid immunosuppressive checkpoint markers. FNA samples were representative of the tumor as a whole as assessed by head-to-head comparison to single cell suspensions of dissociated whole tumor. Parallel analysis of matched patient blood enabled us to establish quality assurance criteria to determine the accuracy of FNA procedures to sample tumor tissue. FNA biopsies provide a diagnostic to rapidly phenotype the tumor immune microenvironment that may be of great relevance to clinical trials.

In plain English

This laboratory methods study tested whether fine needle aspirate (FNA) biopsies could be used to profile the immune cells inside tumors. It did not study asbestos exposure. First, in tumors removed from seven patients with non-small cell lung cancer, FNA gave more living cells than core needle biopsies, with over 10,000 viable cells in 6 of 7 samples. Next, in 13 patients having surgery for malignant pleural mesothelioma, a single ultrasound-guided needle pass before surgery gave enough cells for analysis in 8 of 13 cases. The authors compared these samples with each patient's removed tumor and blood. In a clustering analysis, seven of the eight FNA samples grouped with the tumor samples. The sample from one patient resembled blood, which the authors said suggested contamination. T cells in both the FNA and tumor samples showed high levels of PD-1, an inhibitory receptor. The authors concluded that FNA yields data representative of the whole tumor. They noted that the single-pass method may explain the five samples with too few cells.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory methods development study comparing immune-cell profiling (flow cytometry) of fine needle aspirate biopsies with core needle biopsies, dissociated resected tumor and matched blood
• Who was studied: 13 patients with suspected or proven malignant pleural mesothelioma undergoing surgery, enrolled on Dana-Farber/Harvard Cancer Center protocols in Boston. Seven non-small cell lung cancer patients were also studied for the needle-type comparison. Study dates are not given.
• Exposure: No exposure was studied. The article does not address asbestos or any fiber type. It compares tissue-sampling methods.
• Main results:
  • In the 7 non-small cell lung cancer tumors, FNA gave more viable cells than core biopsies. FNA gave over 10,000 viable cells in 6 of 7 samples, with a mean of 20,455 and SEM of 6,544.
  • In mesothelioma patients, a single-pass FNA gave enough cells for flow cytometry in 8 of 13 cases
  • In mesothelioma patients, FNA gave a greater percentage of live cells than the resected tumor specimen. FNA gave fewer total cells.
  • In the t-SNE analysis of the 8 mesothelioma patients with full data, samples formed two groups. One group was the 8 blood samples plus 1 FNA. The other was all 8 tumor samples plus the remaining 7 FNA samples.
  • The FNA sample from Patient F resembled that patient's blood rather than the tumor, which the authors said suggested contamination
  • CD8+ and CD4+ T cells showed high PD-1 and moderate to low TIM-3. FNA results matched those from whole tumor.
  • Compared with blood, FNA and tumor samples showed low abundance of CD66b+ granulocytes and higher PD-L1 and PD-L2 expression on CD33+ and CD66b+ cells
• The authors' conclusion: The authors concluded that fine needle aspirate biopsies routinely collect enough viable cells for immune profiling and yield data representative of the whole tumor
• Limitations the authors state:
  • The single-pass protocol may account for the 5 of 13 samples that yielded too few cells
  • Tumor specimens used for comparison were most likely from different locations in the tumor than the FNA sites
  • Low cell yield meant FNA could not be profiled with the full antibody panel used for resected tumors
  • In some patients, FNA and tumor results were slightly discordant

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Aspirate, Mesothelioma, Clinical Trial, Immunotherapy, Biopsy.

Related studies

• Cytotoxic T Cells in PD-L1-Positive Malignant Pleural Mesotheliomas Are Counterbalanced by Distinct Immunosuppressive Factors — M.M. Awad, R.E. Jones, et al. (2016)
• Direct comparison of liquid-based and smear-based cytology with and without rapid on-site evaluation for fine needle aspirates of thoracic tumors — A. Mfokazi, C.A. Wright, et al. (2016)
• Flow cytometric analysis of ploidy in immunohistochemically confirmed examples of malignant epithelial mesothelioma — H.F. Frierson, S.E. Mills, et al. (1988)
• Flow cytometric measurement of cellular FLICE-inhibitory protein (c-FLIP) in ovarian carcinoma effusions — H.P. Dong, A.K. Ree Rosnes, et al. (2011)
• Critical Roles of Tumor Extracellular Vesicles in the Microenvironment of Thoracic Cancers — L. Kara-Terki, L. Treps, et al. (2020)
• Flow cytometry in the exploration of the physiopathology of occupational lung disease — A.D. Curran (1999)

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