Spatial interaction of tumor cells and regulatory T cells correlates with survival in non-small cell lung cancer

Lung Cancer. 2018 Mar:117:73-79. doi: 10.1016/j.lungcan.2018.01.022. Epub 2018 Feb 4.

Abstract

Objectives: To determine the prognostic significance of spatial proximity of lung cancer cells and specific immune cells in the tumor microenvironment.

Materials and methods: We probed formalin-fixed, paraffin-embedded (FFPE) tissue microarrays using a novel tyramide signal amplification multiplexing technique labelling CD8, CD4, Foxp3, and CD68+ cells. Each multiplex stained immunohistochemistry slide was digitally processed by Vectra INFORMS software, and an X- and Y-coordinate assigned to each labeled cell type. The abundance and spatial location of each cell type and their proximity to one another was analyzed using a novel application of the G-cross spatial distance distribution method which computes the probability of finding at least one immune cell of any given type within a rμm radius of a tumor cell. Cox proportional hazards multiple regression was used for multivariate analysis of the influence of proximity of lymphocyte types.

Results: Pathologic tumor specimens from 120 NSCLC patients with pathologic tumor stage I-III disease were analyzed. On univariate analysis, age (P = .0007) and number of positive nodes (P = .0014) were associated with overall survival. Greater area under the curve (AUC) of the G-cross function for tumor cell-Treg interactions was significantly associated with worse survival adjusting for age and number of positive nodes (HR 1.52 (1.11-2.07), P = .009). Greater G-cross AUC for T-reg-CD8 was significantly associated with better survival adjusting for age and number of positive lymph nodes (HR 0.96 (0.92-0.99), P = .042).

Conclusion: Increased infiltration of regulatory T cells into core tumor regions is an independent predictor of worse overall survival in NSCLC. However, increased infiltration of CD8+ cytotoxic T cells among regulatory T cells seems to mitigate this effect and was significantly associated with better survival. Validation of the G-cross method of measuring spatial proximity between tumor and immune cell types and exploration of its use as a prognostic factor in lung cancer treatment is warranted.

Keywords: Immune cells; Intratumoral T cells; Non-small cell lung cancer; Spatial computation; Spatial distances; T regulatory cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • CD8-Positive T-Lymphocytes / pathology*
  • Carcinoma, Non-Small-Cell Lung / diagnosis*
  • Carcinoma, Non-Small-Cell Lung / immunology
  • Carcinoma, Non-Small-Cell Lung / mortality
  • Cytotoxicity, Immunologic
  • Female
  • Humans
  • Immunohistochemistry
  • Lung Neoplasms / diagnosis*
  • Lung Neoplasms / immunology
  • Lung Neoplasms / mortality
  • Male
  • Middle Aged
  • Models, Theoretical
  • Neoplasm Staging
  • Predictive Value of Tests
  • Prognosis
  • Survival Analysis
  • T-Lymphocytes, Regulatory / pathology*
  • Tissue Array Analysis
  • Tumor Microenvironment