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.
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.