Predictive Biomarkers and Personalized Medicine Multiple Loci Modulate Opioid Therapy Response for Cancer Pain

Purpose: Patients treated with opioid drugs for cancer pain experience different relief responses, raising the possibility that genetic factors play a role in opioid therapy outcome. In this study, we tested the hypothesis that genetic variations may control individual response to opioid drugs in cancer patients. Experimental Design:We tested 1million single-nucleotide polymorphisms (SNP) in European cancer patients, selected in a first series, for extremely poor (pain relief 40%; n1⁄4 145) or good (pain relief 90%; n 1⁄4 293) responses to opioid therapy using a DNA-pooling approach. Candidate SNPs identified by SNParray were genotyped in individual samples constituting DNA pools as well as in a second series of 570