[Effect of concurrent chemoradiotherapy and radiotherapy alone on peripheral myeloid-derived suppressor and T regulatory cells in patients with nasopharyngeal cancer]

The analysis of Treg lymphocyte blood percentage changes in patients with head and neck cancer during combined oncological treatment: a preliminary report

Introduction

In patients with cancer, Treg lymphocytes seem to play an important role in promoting tumour growth. The number of circulating Treg cells has been associated with poor survival among patients suffering from various types of cancers. The aim of the present study was to evaluate the changes in the percentage levels of Treg lymphocytes in the blood samples of patients with head and neck cancer during combined treatment with respect to the stage of the disease and the intensity of the radiation reaction as monitored using the Dische scale.

Material and methods

Peripheral blood samples were collected from 20 head and neck cancer patients prior to the combined oncological treatment, during, and then one week after the completion of the therapy.

Results

A statistically significantly higher percentage of CD3⁺/CD4⁺/CD25⁺/FoxP3⁺/CD127(^–/low) T cells within the CD3⁺/CD4⁺ T cell population was detected in patients during radiotherapy (RTH), chemotherapy (CTH), and chemoradiotherapy (CRT) than before the treatment began (p < 0.0001). A statistically significantly higher percentage of CD3⁺/CD4⁺/CD25⁺/FoxP3⁺/CD127(^–/low) T cells within the CD3⁺/CD4⁺ T cell population was detected after RTH/CRT than before treatment, with respect to the radiation reaction as evaluated using the Dische scale (p = 0.0150).

Conclusions

The increase in the percentage of Treg cells correlated with an increase in the intensity of the radiation reaction measured using the Dische scale which indicates the advance of the oral mucositis reaction to RTH. In conclusion, because the role of Treg lymphocytes in cancer patients is complex, it is necessary to monitor the percentages of these cells in patients during combined oncological therapies.

The Microenvironment in Epstein-Barr Virus-Associated Malignancies

The Epstein–Barr virus (EBV) can cause a wide variety of cancers upon infection of different cell types and induces a highly variable composition of the tumor microenvironment (TME). This TME consists of both innate and adaptive immune cells and is not merely an aspecific reaction to the tumor cells. In fact, latent EBV-infected tumor cells utilize several specific mechanisms to form and shape the TME to their own benefit. These mechanisms have been studied largely in the context of EBV+ Hodgkin lymphoma, undifferentiated nasopharyngeal carcinoma, and EBV+ gastric cancer. This review describes the composition, immune escape mechanisms, and tumor cell promoting properties of the TME in these three malignancies. Mechanisms of susceptibility which regularly involve genes related to immune system function are also discussed, as only a small proportion of EBV-infected individuals develops an EBV-associated malignancy.