Cetuximab responses in HNSCC patients correlate to clonal expansion feature of peripheral and tumor-infiltrating T cells with top T cell receptor (TCR) clonotypes.

Cetuximab-treated HNSCC patients harbor dynamic changes of TCR repertoires correlative to therapeutic responses. The expansion rate of top TCR clonotypes in peripheral blood may serve as a minimally invasive, readily accessible, and feasible marker for predicting cetuximab responses in HNSCCs and beyond, and the expansion rate of top TCR clonotypes in TILs and their overlapping probability between PBMC and TIL may serve as additional predictive markers. Our study also highlights the importance of data normalization for TCR repertoire analysis.