Polymorphism in glutathione S-transferase P1 is associated with susceptibility to chemotherapyinduced leukemia

Glutathione S-transferases (GSTs) detoxify potentially mutagenic and toxic DNA-reactive electrophiles, including metabolites of several chemotherapeutic agents, some of which are suspected human carcinogens. Functional polymorphisms exist in at least three genes that encode GSTs, including GSTM1, GSTT1, and GSTP1. We hypothesize, therefore, that polymorphisms in genes that encode GSTs alter susceptibility to chemotherapy-induced carcinogenesis, specifically to therapy-related acute myeloid leukemia (t-AML), a devastating complication of long-term cancer survival. Elucidation of genetic determinants may help to identify individuals at increased risk of developing t-AML. To this end, we have examined 89 cases of t-AML, 420 cases of de novo AML, and 1,022 controls for polymorphisms in GSTM1, GSTT1, and GSTP1. Gene deletion of GSTM1 or GSTT1 was not specifically associated with susceptibility to t-AML. Individuals with at least one GSTP1 codon 105 Val allele were significantly over-represented in t-AML cases compared with de novo AML cases [odds ratio (OR), 1.81; 95% confidence interval (CI), 1.11–2.94]. Moreover, relative to de novo AML, the GSTP1 codon 105 Val allele occurred more often among t-AML patients with prior exposure to chemotherapy (OR, 2.66; 95% CI, 1.39–5.09), particularly among those with prior exposure to known GSTP1 substrates (OR, 4.34; 95% CI, 1.43–13.20), and not among those t-AML patients with prior exposure to radiotherapy alone (OR,1.01; 95% CI, 0.50–2.07). These data suggest that inheritance of at least one Val allele at GSTP1 codon 105 confers a significantly increased risk of developing t-AML after cytotoxic chemotherapy, but not after radiotherapy

Tobacco and alcohol consumption and the risk of non-Hodgkin lymphoma

OBJECTIVE: The aim was to test whether non-Hodgkin lymphoma (NHL) is associated with smoking or alcohol. METHODS: A case-control study recruited NHL cases aged 18-64 in parts of England between 1998 and 2001. One control was matched to each case on sex, date of birth and area of residence. Self-reported histories of tobacco and alcohol consumption were collected during face-to-face interviews. RESULTS: Among 700 cases and 915 controls, no association of smoking with the risk of NHL was observed [odds ratio (OR)= 1.04, 95% confidence interval (CI): 0.85-1.28]. Risks were not raised with age started smoking, number of years smoked, and number of years stopped smoking. Compared with persons who drank alcohol once or twice a week, neither abstainers (OR = 1.03, 95% CI: 0.64-1.67), nor consumers of alcohol one to five times a year (OR = 1.35, 95% CI: 0.95-1.93), one to two times a month (OR = 1.20, 95% CI: 0.87-1.65), three to four times a week (OR = 0.82, 95% CI: 0.62-1.10), or most days (OR = 0.94, 95% CI: 0.70-1.25) increased their risk of developing NHL. Average daily volume or high occasional alcohol consumption were not associated with NHL. CONCLUSIONS: NHL was not associated with smoking or alcohol, but collaborative studies could further investigate the risks of rarer WHO subtypes following these exposures