The AA genotype of rs4680 or A_T_C_A/ A_T_C_A (rs6269_rs4633_ rs4818_rs4680) diplotype of COMT, combined with the AG genotype of OPRM1 A118G, showed significantly increased pressure pain threshold from butorphanol.
We detected significant association of the rs1051660 adjusted on metastasis and pain (<i>P</i>=0.02), no other association has been detected between the 7 polymorphisms screened and the dose of morphine needed for pain relief.