Ellingjord-Dale et al. Page 1752

Twin studies suggest that variation in mammographic density (MD) is genetically determined. To examine if breast cancer susceptibility genes affect MD, Ellingjord-Dale and colleagues assessed breast cancer gene SNPs and MD in postmenopausal women from the Norwegian Breast Cancer Screening Program. They determined the association between 17 established breast cancer gene variants and MD. The authors identified two gene variants (6q25.1-rs9383938 and TXNRD2-rs8141691) with statistically significant associations with percent MD. This study provides novel evidence of possible MD genetic–environmental interactions.

Brand et al. Page 1764

The clinical utility of mammographic density is hampered by the lack of objective and automated measures. Brand and colleagues evaluated the performance of Volpara, a fully automated volumetric method to assess mammographic density. The study included 41,102 women and percent and absolute dense volume were estimated from raw digital mammograms. The method showed good agreement of percent and absolute dense volumes across several mammography systems. In a high-throughput setting, Volpara performed well and is a promising tool for widespread breast cancer risk assessment.

Chenoweth et al. Page 1773

High nicotine metabolite ratios (NMR) are strongly associated with heavy smoking and low smoking cessation rates. CYP2A6-gene variants influence NMR, as do demographic and hormonal factors, but the sizes of these effects were not clear. Chenoweth and colleagues analyzed demographic and hormonal sources of variation on NMR in active smokers. They report that these two factors contributed little to total NMR and are unlikely to cause NMR misclassification.

Westmaas et al. Page 1783

Smoking is detrimental to recovery and survival from cancer, but many cancer survivors continue to smoke. Information is lacking on smoking patterns of cancer survivors many years after diagnosis. Westmaas and colleagues performed cross-sectional analyses among survivors of 10 cancers recruited from cancer registries. Nine years after diagnosis, fewer than 10% of all survivors were current smokers but most of these current smokers smoked daily. Current smoking was associated with younger age, lower education and income, and greater alcohol consumption. This study indicates that smoking can persist long after initial cancer diagnosis.