Genetic variations in benzene metabolism and susceptibility to multiple myeloma

We have previously shown that deficiency in the biotransformation enzyme glutathione-S-transferase theta (GSTT1) is a risk factor for multiple myeloma (MM). The present case–control study of 102 MM patients and 205 controls revealed a significant trend in increasing risk of MM with inheritance of multiple putative ‘high risk’ genetic variants in related pathways of benzene detoxification. Individuals who carried polymorphisms for GSTT1 null and/or high activity microsomal epoxide hydrolase (mEH 113YY + 139HR or 113YY + 139RR or 113YH + 139RR) and/or low activity NAD(P)H:quinone oxidoreductase 1 (NQO1 187PS/SS) were 1.65, 2.49 and 13 times more likely to have MM (Ptrend = 0.001).