Vascular density and inflammatory infiltrate in primary oral squamous cell carcinoma and after allogeneic hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) recipients have been reported to have an increased risk of chronic graft versus host disease (cGVHD) and hematological and solid cancers. Oral manifestations are the first signs of cGVHD observed in the majority of patients, and oropharyngeal cancer is the most frequent secondary malignancy occurred after HSCT. In this study, we have evaluated the inflammatory infiltrate cell content and correlated with the vascular density in patients affected by primary oral squamous cell carcinoma (OSCC) from previous healthy controls and OSCC after cGVHD. Results have demonstrated that patients with OSCC after GVHD show a more consistent inflammatory infiltrate as compared with the OSCC ones. In detail, the inflammatory background composed of CD3-positive T cells, tryptase-positive mast cells, CD31-positive endothelial cells, and CD68-positive macrophages may be more pronounced in the setting of GVHD + OSCC than in the control group. By contrast, CD20-positive B cells and CD1a-positive dendritic cells were more abundant in the latter population. Finally, a positive correlation was found as between vascular density and inflammatory cell infiltration in both GVHD + OSCC and OSCC groups. Overall, these results confirm the role played by immune cells in enhancing tumor progression and angiogenesis and suggest a potential therapeutic strategy involving inhibition of recruitment of immune cells to the tumor microenvironment and blockade of pro-tumoral effects and pro-angiogenic functions.