AB060. Multiplex immunofluorescence analysis of potential targets in thymic epithelial tumors
Abstract

AB060. Multiplex immunofluorescence analysis of potential targets in thymic epithelial tumors

Vanya Aggarwal1, Susree Modepalli2, Jaeil Ahn2, Jennifer Marks1, Jacob Zaemes1, Anju Duttargi2, Chul Kim1

1Georgetown Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC, USA; 2Georgetown University, Washington, DC, USA

Correspondence to: Vanya Aggarwal, MD. Georgetown Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, 3800 Reservoir Road, Washington, DC 20007, USA. Email: vanya.aggarwal@medstar.net.

Background: There is an unmet need for novel treatment options in thymic epithelial tumors (TETs). Newer targeted therapies, including antibody-drug conjugates (ADCs), have potential application for TETs. B7-H3, B7-H4, nectin-4, HER2, HER3, and CLDN 18.2 are biomarkers, for which ADCs are being assessed or have been approved for certain cancer types. We evaluated expression of these biomarkers in TET.

Methods: Patients with TETs treated at MedStar Georgetown University Hospital were retrospectively identified. Multiplex immunofluorescence staining for B7-H3, B7-H4, nectin-4, HER2, HER3, and CLDN 18.2 were performed, and expression was evaluated using InForm tissue analysis software. For each specimen, ten representative areas from the tumor center and periphery were chosen by a pathologist for analysis.

Results: Thirty-eight TET samples were identified, 24 thymomas (T) and 14 thymic carcinomas (TC). In the tumor center, mean expression of B7-H3 was 17%, B7-H4 20%, nectin-4 11%, HER2 0%, HER3 27%, CLDN 18.2 6%. When grouped by tumor type, B7-H3 expression was 13% in T and 24% in TC (P=0.056), B7-H4 expression was 18% in T and 23% in TC (P=0.41), nectin-4 was 5% in T and 20% in TC (P=0.002), HER2 was 0% in T and TC (P=0.16), HER3 was 30% in T and 22% in TC (P=0.31), and CLDN 18.2 was 2% in T and 12% in TC (P=0.003). In the tumor periphery, mean expression of B7-H3 was 24%, B7-H4 10%, nectin-4 14%, HER2 3%, HER3 28%, CLDN 18.2 9%. When grouped by tumor type, B7-H3 expression was 27% in T and 18% in TC (P=0.28), B7-H4 expression was 7% in T and 16% in TC (P=0.08), nectin-4 was 8% in T and 25% in TC (P=0.001), HER2 was 1% in T and 8% in TC (P<0.001), HER3 was 27% in T and 30% in TC (P=0.69), and CLDN 18.2 was 10% in T and 6% in TC (P=0.25).

Conclusions: Expression of B7-H3, B7-H4, HER3, CLDN 18.2 and nectin-4 was observed in TET. Heterogeneity across individual samples and tumor types was noted with nectin-4 being higher in TC. The results might guide future therapeutic development of ADCs in TETs.

Keywords: Multiplex; B7-H3; B7-H4; HER3; nectin-4

Acknowledgments

Funding: None.

Footnote

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://med.amegroups.com/article/view/10.21037/med-24-ab060/coif). J.M. reports honorarium from Medstar CME, Gather-Ed/Prova, Curio, travel awards from Precisca, IDEOlogy, MJH Life Sciences, and R&D authorship from Janssen. J.Z. reports consulting for MJH Life Sciences. C.K. reports contracts/grants from AstraZeneca, Novartis, Regeneron, Janssen, Genentech, Lyell, Daiichi Sankyo, Gilead, Macrogenics, Boehringer Ingelheim, Black Diamond Therapeutics, ORIC Pharmaceuticals and consulting fees from AstraZeneca, Daiichi Sankyo, Eisai, Regeneron, Sanofi, Takeda, J&J, Pinetree, Boehringer Ingelheim, Gencurix, Bayer, Mirati, Jazz, Arcus, Diffusion pharmaceuticals. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). The study was approved by the Georgetown University Institutional Review Board (No. STUDY00004084) and individual consent for this retrospective analysis was waived.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

doi: 10.21037/med-24-ab060
Cite this abstract as: Aggarwal V, Modepalli S, Ahn J, Marks J, Zaemes J, Duttargi A, Kim C. AB060. Multiplex immunofluorescence analysis of potential targets in thymic epithelial tumors. Mediastinum 2024;8:AB060.

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