Tumor Infiltrating Immune Cells And Outcome of Merkel Cell Carcinoma: A Population-based Study
Menée en Finlande sur 116 patients atteints d'un carcinome à cellules de Merkel, cette étude évalue l'association entre le nombre intratumoral de cellules immunitaires, la présence d'ADN du polyomavirus à cellules de Merkel, les caractéristiques des tumeurs et la survie des patients
Purpose: Merkel cell carcinoma (MCC) is a rare skin cancer that often harbors Merkel cell polyomavirus (MCPgammaV) DNA. The clinical importance of intratumoral immune cells and their associations with MCPgammaV infection are poorly understood. Experimental Design: We identified T-lymphocytes (CD3-positive cells), T cell subsets (CD4, CD8, and FoxP3-positive cells), natural killer cells (small CD16-positive cells), and macrophages (CD68 and CD163-positive cells) in tumors of 116 individuals diagnosed with MCC in Finland from 1979 to 2004 using immunohistochemistry, and detected MCPgammaV DNA with quantitative PCR. The associations between immune cell counts, MCPgammaV DNA, patient and tumor characteristics, and patient outcome were examined. Results: MCPgammaV DNA-positive cancers contained higher numbers of CD3+, CD8+, CD16+, FoxP3+, and CD68+ cells as compared to MCPyV DNA-negative carcinomas (all P-values less than 0.05). High intratumoral numbers of CD3+, CD8+, or FoxP3+ cells, and high CD8+/CD4+ or FoxP3+/CD4+ ratios were significantly associated with favorable overall survival. Individuals with a high tumor CD3+ count had less often metastases and survived longer irrespective of the tumor MCPgammaV status. Tumor CD3+ count and MCPgammaV DNA-status had independent influence on survival in a Cox multivariable model that included also presence of locoregional metastases at diagnosis and gender as covariates. Conclusions: High intratumoral T-lymphocyte counts are associated with favorable survival in MCC. Although the numbers of T-cells are generally higher in MCPgammaV-positive than in MCPgammaV-negative MCC, high intratumoral T-cell counts are associated with favorable survival also in MCPgammaV-negative MCC.
Clinical Cancer Research , résumé, 2012