Cancer cells can acquire immune resistance resulting in a loss of immunosurveillance. Tumor cells can upregulate PDL-1 which binds to PD-1. This complex inhibits CD8 Tumor Infiltrating cells ( TILs) response to tumor antigens inducing immune blockade. Anti-blockade immunotherapy blocks the blockade and restores immunosurveillance (self-healing).This presentation emphasizes clinical examples of immunotherapy with both an individual patient with malignant melanoma and population-based examples including triple negative breast cancer.. The cases demonstrate the importance of intact tissue chemistry, in particular multi-analyte immunohistochemistry to inform treatment.. It emphasizes the future need to add more markers and cancer types to the testing repertoire and the need to go beyond diagnosis to prediction and monitoring of immunotherapy responses.
1. Understand the concepts of tumor immunosurveillance, immune blockade, and immune restoration via immunotherapy
2. Understand the pivotal role of the diagnostic laboratory in informing immunotherapy by using intact multi-analyte immunohistochemistry.