The OPRM1 A118G single nucleotide polymorphism (SNP) is a key contributor for the inter-individual variability in opioidrequirements in Chinese cancer pain patients.
The association between COMT Val158Met polymorphism (rs4680) and the inter-individual differences in the response to opioid analgesic therapy was investigated in a cohort of 87 Italian paediatric patients receiving opioids for cancer pain (STOP Pain study).
Based on this information we analyzed the influence from the COMT Val158Met polymorphism on the efficacy of morphine in a cohort of patients suffering from cancer pain.
Five SNPs (rs3732765, rs9859538, rs17283010, rs11713504, and rs10935840) of the P2RY12 gene were significantly associated with cancer pain severity, although opioid requirements were comparable in each genotype of the five SNPs.
The genotypes of rs1799971 (OPRM1) and rs1045642 (ABCB1) were determined by PCR-RFLP and direct sequencing methods respectively in 112 patients with cancer-related pain.