S B Strobel1, K Safferling2,3, B Lahrmann2,3, J H Hoffmann1, A H Enk1, E N Hadaschik1,4, N Grabe2,3, A S Lonsdorf1. 1. Department of Dermatology, Ruprecht-Karls-University of Heidelberg, Heidelberg, Germany. 2. Hamamatsu Tissue Imaging and Analysis Center, BIOQUANT, Heidelberg, Germany. 3. Department of Medical Oncology, National Center for Tumor Diseases Heidelberg, Ruprecht-Karls-University of Heidelberg, Heidelberg, Germany. 4. Department of Dermatology, University of Essen, Essen, Germany.
Abstract
BACKGROUND: The inflammatory tumour microenvironment is crucial for effective tumour control, and long-term immunosuppression has been identified as a major risk factor for skin carcinogenesis. In solid organ transplant recipients (OTRs) undergoing long-term pharmacological immunosuppression, an increased incidence of cutaneous squamous cell carcinoma (SCC) and more aggressive tumour growth compared with immunocompetent patients has been reported. OBJECTIVES: To determine the density and phenotype of immune cells infiltrating SCC and surrounding skin in OTRs, and to characterize the microanatomical distribution patterns in comparison with immunocompetent patients. METHODS: We analysed immune cell infiltrates within SCC and at defined regions of interest (ROIs) of tumour-surrounding skin in formalin-fixed paraffin-embedded tissue of 20 renal transplant patients and 18 carefully matched immunocompetent patients by high-resolution semiautomated microscopy on complete tissue sections stained for CD4, CD8, CD20 and CD68. RESULTS: The overall immune cell density of SCC arising in OTRs was significantly reduced compared with immunocompetent patients. Particularly CD4+ infiltrates at the directly invasive margin and tumour vicinity, intratumoral CD8+ T-cell densities and the overall density of CD20+ tumour-infiltrating B cells were significantly reduced in the tissue of OTRs. CONCLUSIONS: Immune cell infiltrates within SCC and at defined ROIs of tumour-surrounding skin in OTRs differ markedly in their composition and microanatomical distribution compared with tumours arising in immunocompetent patients. Our findings substantially broaden the understanding of how long-term systemic immunosuppression modulates the local inflammatory microenvironment in the skin and at the site of invasive SCC.
BACKGROUND: The inflammatory tumour microenvironment is crucial for effective tumour control, and long-term immunosuppression has been identified as a major risk factor for skin carcinogenesis. In solid organ transplant recipients (OTRs) undergoing long-term pharmacological immunosuppression, an increased incidence of cutaneous squamous cell carcinoma (SCC) and more aggressive tumour growth compared with immunocompetent patients has been reported. OBJECTIVES: To determine the density and phenotype of immune cells infiltrating SCC and surrounding skin in OTRs, and to characterize the microanatomical distribution patterns in comparison with immunocompetent patients. METHODS: We analysed immune cell infiltrates within SCC and at defined regions of interest (ROIs) of tumour-surrounding skin in formalin-fixed paraffin-embedded tissue of 20 renal transplant patients and 18 carefully matched immunocompetent patients by high-resolution semiautomated microscopy on complete tissue sections stained for CD4, CD8, CD20 and CD68. RESULTS: The overall immune cell density of SCC arising in OTRs was significantly reduced compared with immunocompetent patients. Particularly CD4+ infiltrates at the directly invasive margin and tumour vicinity, intratumoral CD8+ T-cell densities and the overall density of CD20+ tumour-infiltrating B cells were significantly reduced in the tissue of OTRs. CONCLUSIONS: Immune cell infiltrates within SCC and at defined ROIs of tumour-surrounding skin in OTRs differ markedly in their composition and microanatomical distribution compared with tumours arising in immunocompetent patients. Our findings substantially broaden the understanding of how long-term systemic immunosuppression modulates the local inflammatory microenvironment in the skin and at the site of invasive SCC.
Authors: Gesche Frohwitter; Marie Kerta; Christoph Vogl; Carol Immanuel Geppert; Jan-Erik Werry; Jutta Ries; Marco Kesting; Manuel Weber Journal: Front Oncol Date: 2022-04-07 Impact factor: 5.738