Highlights of This Issue

Using cases from several Australian pediatric oncology centers, Milne and colleagues investigated the protective effects of maternal folic acid against childhood brain tumors. Their work represents the largest study of its kind and provides evidence of an inverse association between childhood brain tumors and folic acid use before pregnancy. These findings are intriguing given that the folic acid/brain cancer connection is biologically plausible through established mechanisms.

Previous studies have suggested that vitamin B6 may reduce the risk of breast cancer. Lurie and colleagues examined the association of plasma concentrations of PLP (an active form of vitamin B6) with postmenopausal breast cancer risk. They report that women with high plasma PLP concentrations had a 30% reduced risk of invasive breast cancer compared with women with lower PLP levels. This association appeared to be limited to cases with hormone receptor–positive tumors. These results suggest a role for vitamin B6 in the prevention of postmenopausal breast cancer and indicate a potential heterogeneity of the association by tumor hormone receptor status.

Although cervical infection with high-risk human papillomavirus (HPV) is considered a cause of cervical cancer, smoking has also been associated with cervical cancer. Jensen and colleagues used structured interviews, HPV DNA analysis, and up to 13 years of cervical lesion follow-up to explore the relationships among smoking, HPV, and cervical cancer. The authors report that among woman with persistent, high-risk HPV infection, the risk for future high-grade cervical lesions was associated with both long- term and heavy smoking. This work strengthens the role of smoking in the natural history of HPV and cervical carcinogenesis.

In the United States, prostate cancer incidence rates are dramatically low in Latino and Japanese men. To explore the reasons for this, Cheng and colleagues conducted genomewide association studies, tested prostate cancer risk variants, and developed genetic risk models in U.S. Japanese and Latino populations. Although no new genome-wide significant prostate cancer loci were uncovered, the authors report that known risk variants contribute to prostate cancer susceptibility in both populations. This important study helps define the risk alleles that contribute to prostate cancer in Japanese and Latino men.