Highlights of This Issue

The World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) guidelines encourage cancer survivors to follow their cancer prevention recommendations. Inoue-Choi and colleagues assessed whether adherence to the WCRF/AICR guidelines was associated with lower mortality among older female cancer survivors. The authors report that women with the highest adherence levels had lower all-cause mortality, compared with women with the lowest adherence level. Adherence to the physical activity recommendation had the strongest association with lower all-cause and disease-specific mortality. This report emphasizes the importance of leading a healthy lifestyle after a cancer diagnosis.

Heterogeneous diseases are comprised of multiple subtypes, each with its own unique set of biomarkers, affecting the design and analysis of biomarker discovery studies. Wellstrom and colleagues used Monte Carlo simulation to compare 8 biomarker selection methods for homogeneous and heterogeneous diseases with single-and 2-stage designs. The authors report that more than 2-fold larger sample sizes were needed for heterogeneous diseases, compared with homogeneous diseases. The report includes important sample size requirements and study design guidance for biomarker discovery studies.

Exercise can decrease breast cancer risk, and this could be mediated through changes in estrogen metabolism in premenopausal women. Smith and colleagues investigated the effects of exercise on premenopausal estrogen metabolism. Women were randomly assigned into an aerobic exercise intervention group or a sedentary control group, and urinary levels of estrogens and estrogen metabolites were measured at baseline and at the end of the study. The exercise intervention resulted in a significant increase in a particular estrogen metabolite ratio (2-OHE1/16α-OHE1), suggesting that changes in premenopausal estrogen metabolism may be a mechanism by which increased physical activity lowers breast cancer risk.

Hepatitis B–linked liver cancer disproportionately affects Hmong Americans; this population experiences liver cancer at a rate 6- to 7-fold greater than that of non-Hispanic whites. Chen and colleagues present a 5-year randomized controlled trial testing a lay health worker (LHW) intervention to promote hepatitis B virus (HBV) testing among Hmong adults. Intervention group participants were more likely to report receiving HBV serologic testing and showed increased knowledge scores, compared with the control group. Although the LHW intervention significantly increased Hmong HBV screening rates, the most often cited reason for testing was a doctor's recommendation.