1.
Long-term Effects of Moderate versus High Durations of Aerobic Exercise on Biomarkers of Breast Cancer Risk: Follow-up to a Randomized Controlled Trial.
Friedenreich, CM, Wang, Q, Yasui, Y, Stanczyk, FZ, Duha, A, Brenner, DR, Courneya, KS
Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology. 2019;(10):1725-1734
Abstract
BACKGROUND The optimal lifestyle for breast cancer prevention over the long term is unclear. We aimed to determine whether or not the amount of exercise prescribed in a year-long exercise intervention influences breast cancer biomarker levels 1 year later. METHODS We conducted a 24-month follow-up study (2012-2014) to the Breast Cancer and Exercise Trial in Alberta (BETA), a 12-month, two-armed (1:1), two-center randomized controlled trial of exercise in 400 cancer-free, postmenopausal women. The exercise prescription was moderate-vigorous aerobic exercise, 5 days/week (3 days/week supervised) for 30 minutes/session (MODERATE) or 60 minutes/session (HIGH). Participants were asked not to change their usual diet. We used linear mixed models to compare biomarker concentrations (C-reactive protein, insulin, glucose, HOMA-IR, estrone, sex hormone binding globulin, total estradiol, and free estradiol) over time (0, 12, and 24 months) by group (MODERATE, HIGH), using group-time interactions. RESULTS After 12 months of no intervention, 24-month fasting blood samples were available for 84.0% and 82.5% of MODERATE and HIGH groups, respectively (n = 333/400). We found no evidence that 0 to 24- or 12 to 24-month biomarker changes differed significantly between randomized groups (HIGH:MODERATE ratio of mean biomarker change ranged from 0.97 to 1.06, P values >0.05 for all). We found more favorable biomarker profiles among participants who experienced greater than the median fat loss during the trial. CONCLUSIONS Prescribing aerobic exercise for 300 versus 150 minutes/week for 12 months to inactive, postmenopausal women had no effects on longer-term biomarkers. IMPACT Exercise may lead to larger improvements in breast cancer biomarkers after intervention among women who also experience fat loss with exercise.
2.
SULT1A1 Arg213His polymorphism, smoked meat, and breast cancer risk: a case-control study and meta-analysis.
Lee, H, Wang, Q, Yang, F, Tao, P, Li, H, Huang, Y, Li, JY
DNA and cell biology. 2012;(5):688-99
Abstract
SULT1A1 is involved in both detoxification of estrogens and bioactivation of carcinogens in smoked meat. SULT1A1 Arg213His polymorphism's effect on breast cancer risk is still unclear. We recruited 400 case-control pairs to investigate the association between SULT1A1 genotypes and breast cancer risk, and the combined effect of SULT1A1 polymorphism and daily intake of smoked meat. Participants were questioned about their dietary habits and other risk factors, and their SULT1A1 genotypes were determined. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were estimated by multivariable unconditional logistic regression. We also performed a meta-analysis of relevant published studies to test these associations. In the case-control study, no significant associations were observed between SULT1A1 polymorphism and breast cancer risk. In the meta-analysis, SULT1A1 His/His genotype slightly increased risk among both overall and postmenopausal women (OR(pooled-overall)=1.12, 95% CI: 1.02-1.24; OR(pooled-post)=1.17, 95% CI: 1.03-1.32). A larger positive association was observed in Asian populations (OR(pooled-Asian)=2.01, 95% CI: 1.24-3.26). In our case-control study, high energy-adjusted daily intake of smoked meat was significantly associated with breast cancer risk in overall, pre- and postmenopausal women (aORs: 2.31-3.13, OR 95% CIs exclude 1). High smoked meat intake interacted positively with the His variant allele (all γ>1). These results correlated with those of the meta-analysis (γ(pooled-overall)=1.27). The SULT1A1 His/His genotype may increase the risk of breast cancer among Asian women, and dietary exposure to heterocyclic amines and polycyclic aromatic hydrocarbons, along with the SULT1A1 His/His variant genotype, may synergistically increase the risk of breast cancer.