Question

Immunohistochemistry (IH in lung cancer.

Hint:

IHC is essential for identifying biomarkers in lung cancer, helping guide targeted therapies and immunotherapies for better outcomes.

Answer 1

Step 1: Understanding Immunohistochemistry (IHC).
Immunohistochemistry (IHC) is a laboratory technique used to detect specific antigens in tissue sections using antibodies. IHC is crucial for diagnosing lung cancer, determining the type of cancer, and guiding treatment. It involves applying antibodies to tumour tissue samples, which bind to target proteins and are visualized using various detection methods.

Step 2: Role of IHC in Lung Cancer.
IHC is primarily used to differentiate between various types of lung cancers and to identify specific molecular markers that can guide treatment decisions. Key uses of IHC in lung cancer include:

Distinguishing between NSCLC and SCLC: IHC helps differentiate between non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) based on the expression of specific markers.
Subtyping of NSCLC: In cases of NSCLC, IHC can be used to further subtype the tumour into adenocarcinoma, squamous cell carcinoma, or large cell carcinoma, based on the expression of markers like TTF-1, Napsin A, and p63.
Detection of Genetic Mutations: IHC can identify the overexpression of proteins related to specific genetic mutations (e.g., EGFR, ALK, ROS1), which can inform targeted therapy options.
Prognostic and Predictive Biomarkers: IHC can assess the expression of markers like PD-L1, which is useful for predicting the response to immunotherapy.

Step 3: Conclusion.
IHC plays a critical role in the diagnosis, subtyping, and treatment planning of lung cancer. It enables personalized treatment based on tumour markers and genetic mutations.