The quantification of tumor-infiltrating lymphocytes (TILs) in non–small cell lung cancers (NSCLCs) is valuable for understanding patient prognosis and survival. TILs comprise a subset of tumor-infiltrating leukocytes that modulate immune evasion and response to therapy. Understanding the composition of TIL subsets, including the distribution in the tumor nests and surrounding stroma, relative to the total tumor leukocyte population, may provide additional context for understanding NSCLC pathogenesis and patient response to treatment. The availability of tissues and use of chromogenic assays can limit the number of TIL and leukocyte subset markers assayed in a tissue section. Flagship Biosciences has developed Computational Tissue Analysis (cTA™) tools that use tissue morphometrics to separate tumor nests from the surrounding stroma into separate layers for subsequent analysis. This feature allows for the quantification of biomarkers in tumor nests and stroma individually without requiring an immunohistochemistry (IHC) biomarker for tumor cells, such as the typically used pan-cytokeratin. The use of tissue morphometrics is particularly applicable in immuno-oncology, where a TIL biomarker such as CD45 can be quantified in both the tumor nests and surrounding stroma (or tumor microenvironment [TME]).
This study therefore identified and evaluated the total leukocyte component in NSCLC using morphometric parameters and routine TIL marker monoplex IHC assays to further identify the composition of TIL subsets. cTA™ tools were used to determine the morphometric parameters, which could identify immune cells in the absence of biomarker staining. The morphometric features that characterized immune infiltrates were used to quantify the total immune cell population frequency in the tumor nests and surrounding stroma in hematoxylin-stained tissues.