Overall survival plots by IL-6 <i>in vitro</i> secretion from LPS-stimulated monocytes.

<p>HNSCC versus control patients (upper panel) and HNSCC patients adjusted by whether HPV infected tumor (lower panel). IL-6 <i>in vitro</i> secretion of purified monocytes determined by ELISA analyses following 24-hour LPS stimulation. Cytokine levels with background subtracted dichotomized by median value to low (continuous line) or high (hatched line) response. Cohort (upper panel): 55 HNSCC and 18 control patients. Cohort (lower panel): 48 HPV-negative and 7 HPV-positive HNSCC patients. Statistics by Kaplan-Meier analyses (Log rank test).