he purpose of this study was to evaluate the prognostic influence of various subtypes
of tumour infiltrating lymphocytes (TIL) in head and neck cancer, in particular the
potential influence of regulatory T cells (Treg) in relation to different treatment
modalities was addressed. A total of 115 patients with squamous cell carcinoma of
the oro- and hypopharynx were selected. A low-risk group of 62 patients with early
disease was treated by primary surgery followed by external radiotherapy. A high-risk
group of 53 inoperable patients with advanced disease was treated by primary radiochemotherapy.
Two-hundred and forty biopsy samples were evaluated by use of the tissue-micro-array
technique employing the following markers: CD3, CD4, CD8, CD20, CD68, FOXP3, Granzyme
B. In the low-risk group high CD20+ infiltration was associated with a significantly
better NED-survival rate (p=0.02). Contrary, among high-risk patients low CD20+ counts
indicated significantly better survival (p=0.03). Additionally, in the low-risk group
higher numbers of intraepithelial CD8+ TIL (>66.6 per thousand) led to improved NED-survival
of 95% vs. 52% (p=0.005). The impact of TIL on prognosis in patients with head and
neck cancer may be affected by type of treatment and stage of disease. This finding
will influence future studies on the role of TIL in human cancers.