May 2008 CEBP Highlights

Preclinical studies have demonstrated the anticancer potential of HMG-CoA reductase enzyme inhibitors (statins) while epidemiological studies remain controversial. Because lipophilic statins show preclinical anticancer activity against hormone receptor (ER/PR) negative breast cancer models, Kumar and colleagues explored the hormone receptor status of breast cancers that arise in statin users. Breast cancer patients with exposure to statins were less likely to have ER/PR negative tumors. They were also less likely to have cancers of high histologic grade and regional stage disease. The authors also found that statin use may influence tumor phenotype. This suggests a new potential strategy for breast cancer prevention, that of combining statins with other preventive agents. In an accompanying editorial, Byers briefly comments on the strength of the evidence for three possible explanations for the observation by Kumar and colleagues: that statins might increase risk of ER positive breast cancer, that statins might decrease risk of ER negative breast cancer, or that statins might somehow switch early breast cancers from an ER negative to an ER positive phenotype. 

 

To evaluate the roles of CYP1A1 polymorphisms [Ile⁴⁶²Val and T⁶²³⁵C (MspI)] and of GSTM1 and GSTT1 deletions in lung cancer development in Asian populations, Lee and colleagues conducted a pooled analysis of 13 existing studies included in the Genetic Susceptibility to Environmental Carcinogenesis database. They found that the trend of increasing lung cancer risk with pack-year was stronger among those with the CYP1A1 6235 TC/CC compared to those with TT genotype, and with the GSTM1 null compared to the GSTM1 present genotype. A significant interactive effect with smoking was not observed for GSTT1. These results suggested that genetic polymorphisms in CYP1A1 and GSTM1 are associated with lung cancer risk in Asian populations.  

Accumulating evidence suggests that vitamin D may protect against cancer, but studies looking into the prospective association of total cancer mortality and serum 25-hydroxyvitamin D [25(OH)D] levels, considered to be the best indicator of vitamin D status, are scarce. Pilz and investigators measured 25(OH)D and the intracellularly converted and more active form, 1,25-dihydroxyvitamin D [1,25(OH)2D], in 3299 patients from the Ludwigshafen Risk and Cardiovascular Health (LURIC) study. They report that low concentrations of serum 25(OH)D but not 1,25(OH)2D were prospectively associated with a reduced risk of fatal cancer. Their data suggest that low levels of 25(OH)D are associated with increased risk of fatal cancer in patients referred to coronary angiography and that the maintenance of a sufficient vitamin D status might therefore be a promising approach for the prevention and/or treatment of cancer.