Immunotherapy and lung cytopathology: Overview and possibilities

Abstract

AbstractImmunotherapy has become a promising cancer treatment in the past decade, and IHC is the most commonly used testing method for PDL‐1/PD1 evaluation. In general, PD‐L1 assays can be performed on both FFPE specimens and cytological samples. However, their use on smears is not yet well‐established or validated. Nowadays, digital images and advanced algorithms can aid in interpreting PD‐L1 in cytological samples. Understanding the immune environment of non‐small cell lung cancer (NSCLC) is critical in developing successful anticancer immunotherapies. The use of a multiplexed immunofluorescence (mIF) assay on cytological samples obtained through minimally invasive methods appears to be a viable option for investigating the immune environment of NSCLC. This review aims to briefly summarize the knowledge of the role of cytopathology in the analysis of PD‐L1 by immunocytochemistry (ICC) and future directions of cytopathology in the immunotherapy setting.