The Tumor Microenvironment and Immunotherapy Resistance
The tumor microenvironment is more than a passive setting—it actively shapes cancer behavior and treatment response. In PD-1 resistant head and neck cancer, the microenvironment often becomes hostile to immune activity.
Cancer-associated fibroblasts, suppressive immune cells, and inflammatory signals can all interfere with immune activation. These components create physical and chemical barriers that prevent immune cells from reaching or attacking tumor cells effectively.
Oxygen deprivation and abnormal blood vessels within tumors further limit immune infiltration. Even when PD-1 inhibitors activate immune cells, they may be unable to penetrate deeply into the tumor mass.
Addressing the tumor microenvironment has become a key focus in overcoming resistance. Therapies designed to normalize blood vessels, reduce suppressive signals, or reprogram immune cells are being explored to complement PD-1 inhibition.
By reshaping the tumor microenvironment, clinicians aim to transform resistant cancers into immune-responsive ones, opening new treatment possibilities.