Background: The study of the nature of tumor-infiltrating lymphocytes (TIL) may provide insight into the complex issue of tumor-host interactions.
Methods: Cytofluorometric analysis was performed to characterize the phenotypic profiles of TIL from non-small-cell lung cancers (NSCLC) and pulmonal metastases of different primary locations. An extensive panel of antibodies was used specific to different activation-associated molecules on T cells. In 10 patients, findings on the T cell phenotype of TIL were compared with the findings in peripheral blood lymphocytes (PBL) from the same patients. Furthermore, we investigated whether the measurement of the TIL phenotype might serve as a prognostic parameter correlating with survival of patients with NSCLC.
Results: In contrast to PBL, T cells infiltrating lung tumors expressed significantly higher amounts of various activation antigens. However, the immunophenotype of TIL hardly differed among different histological subtypes and pulmonal metastases. Addressing the prognostic value of the lymphocytic composition of TIL, we found no significant difference in the survival of NSCLC with high or low percentages of T and natural killer cells, whereas high percentages of B cells were associated with increased survival (p = 0.05). Patients with high percentages of CD13+ tumor-infiltrating T cells had significantly poorer prognosis according to Cox's multivariate analysis.
Conclusion: Our results indicate that different tumor histologies within the lung are characterized by a 'similar' T cell phenotype, at least with respect to the surface molecules studied by us. The measurement of the expression of activation-associated markers on T cells may have prognostic value in the pathological evaluation of NSCLC.