Regulatory vs. cytotoxic cells in lymph nodes of lung cancer patients resected by TEMLA

A balance between tumour invasion and immune defence system is widely investigated. The aim of study was to evaluate lymphocyte phenotype and the expression of FoxP3 in lymph nodes (LN) of patients with lung cancer in relation to presence of metastases. We investigated 226 lymph nodes resected by Transcervical Extended Mediastinal Lymphadenectomy (TEMLA) of 49 patients. There were patients with squamous cell carcinoma (SCC) or adenocarcinoma (AD) with LN metastases (A) and without LN metastases (B). Expression of: CD4, CD8, CD25, FoxP3 was assessed by automated immunohistochemical staining. The slides were reviewed by two independent pathologists and image analysis software. We observed a strong nuclear reaction for FoxP3, strong membranous/cytoplasmatic reaction for CD4, CD8, but low for CD25 with some differences in proportion of cells. A method of lymphocyte calculation remains problematic associated with subjectivity even when automated analysis is used. The significant differences in lymphocyte phenotype in AD may indicate the exceptional biology of this type of lung cancer.