tumor-infiltrating lymphocyte
Also written as: TIL — tumor-infiltrating lymphocyte
Immune cells that have migrated into tumor tissue, serving as biomarkers for immune response and potential predictors of immunotherapy effectiveness.
Full Definition
Tumor-infiltrating lymphocytes (TILs) are T cells, B cells, and natural killer cells that have penetrated into tumor tissue from the circulation. In precision oncology, TIL assessment provides crucial information about the tumor immune microenvironment and patient likelihood of responding to immunotherapies. High TIL density is generally associated with better prognosis and increased immunotherapy response rates across multiple cancer types. TIL evaluation can be performed through histopathological examination, flow cytometry, or molecular profiling techniques. The spatial distribution, density, and phenotypic characteristics of TILs influence treatment decisions, particularly for immune checkpoint inhibitors and adoptive cell therapies.
Usage
Usage note: Use plural 'lymphocytes' when referring to the cell population; singular for individual cells.
In Context
- "High tumor-infiltrating lymphocyte density correlated with improved response to PD-1 inhibitor therapy." — immunotherapy biomarker study
- "The pathology report documented sparse tumor-infiltrating lymphocytes, suggesting an immune-excluded phenotype." — histopathology assessment