ABSTRACT
<p><b>OBJECTIVE</b>To study the potential effect of gene-environment interaction between glutathione S-transferase T1 (GSTT1) and serum organochlorines residues on the risk of breast cancer in women, in China.</p><p><b>METHODS</b>70 newly diagnosed female breast cancer patients and 30 controls from September 2006 to October 2007 were interviewed using the same questionnaire to obtain information regarding exposure to those risks. Organochlorine residues level in serum was measured by gas chromatography (GC). Genotypes of GSTT1 polymorphisms were analyzed by multiplex allele-specific polymerase chain reaction (PCR). Interaction indexes (gamma) were calculated to determine the type of gene-environment interaction.</p><p><b>RESULTS</b>After adjusting the confounding factors, results showed that interaction existed in genetic polymorphisms of GSTT1 and dichlorodiphenyltrichloroethane (DDT)/hexachlorocyclohexane (HCH) residues, with interaction indexes (gamma) value as 1.352 and 1.528.</p><p><b>CONCLUSION</b>Genetic and environmental hazard factors had a co-effect on the development of breast cancer while genetic polymorphisms of GSTT1 and DDT/HCH expressed an interaction to breast cancer.</p>