Absence of Immune Response as a Sign of Tissue Tolerance in Small-Cell Lung Cancer

Abstract

Background: The attention of the scientific community has been recently focused on the role of tumor-infiltrating lymphocytes in non-small-cell cancer and there is a convergence of results, supporting a direct proportionality between lymphocytic infiltrate and good prognosis. Objectives: The aim of our research was to investigate the immune response around and inside the small-cell lung neoplastic tissue and its related neo-lymphangiogenesis in a group of 20 patients. Materials and Methods: We have examined 20 bioptic samples of small cell lung cancer, obtained from 18 men and two women, aged 56-74 years old. Besides hematoxylin-eosin staining, immunohistochemistry for neuroendocrine markers (CD56, chromogranin) and D2-40 was performed following the standard protocols. Results: Our histological analysis, in all cases, has emerged the absence of an immune response supported by an adequate neo-lymphangiogenesis inside the neoplasia. Conclusions: The absence of an immune response is interpreted as a sign of tissue tolerance and host acceptance towards the cancer, in favor of the cancer metastatic spread. The development of a paraneoplastic syndrome can be considered a biochemical proof of this tissue compatibility.