Effect of perioperative opioids on cancer-relevant circulating parameters: Mu opioid receptor and toll-like receptor 4 activation potential, and proteolytic profile

Abstract

Purpose: The purpose of this study is to investigate the potential interplay between opioid analgesia and tumor metastasis through modulation of m-opioid receptor (MOR), Toll-like receptor 4 (TLR4) activation, and matrix degradation potential. Experimental Design: Plasma samples were collected from 60 patients undergoing elective lower limb joint replacement preoperatively and at 3, 6, and 24 hours after surgery; pain scores were documented at the same time points. Opioid administration was recorded and converted into morphine IV equivalents. Plasma samples were also collected from 10 healthy volunteers. Alphascreen cyclic AMP assay and MOR-overexpressing cells were employed to quantify MOR ..