Two studies from the Yale Cancer Center involving breast cancer survivors will be presented at the 2014 annual meeting of the American Society of Clinical Oncology.
“The findings of both studies support a growing body of research that suggests lifestyle interventions lower biomarkers associated with breast cancer recurrence and mortality, and improve quality of life,” said Melinda Irwin, Ph.D., principal investigator on both studies.
In the first study, obese or overweight women were randomized into two groups — those who received weight loss and exercise counseling — and a usual care group that received a brochure about lifestyle changes.
After six months, women in the weight loss counseling group experienced an approximate 30 percent decrease in C-reactive protein (CRP) levels compared with a minimal decrease in women randomized to the usual care group. CRP is a marker of chronic inflammation and higher CRP levels have been associated with a higher risk of breast cancer mortality.
A dose-response effect — meaning that the more a women improved her lifestyle, the less the risk — was found in women randomized to weight loss counseling.
Women who lost at least 5 percent body weight experienced an approximate 22 percent decrease in insulin, 38 percent decrease in leptin, and 55 percent decrease in CRP, compared to significantly less biomarker improvement in women randomized to weight loss who lost less than 5 percent of their body weight.
Another research effort, the hormones and physical exercise (HOPE) study, looked at the effect of exercise on body weight, body fat, and inflammatory biomarkers in 121 women with joint pain from taking cancer medications (aromatase inhibitors, or AI).
Participants were randomized into two groups — those who participated in twice-weekly strength training and 2.5 hr/wk of moderate-intensive aerobic exercise — and those who did no exercise (control group).
After 12 months, the study found that the exercise group experienced an approximate 3 percent weight and body fat loss, and 6 percent decrease in CRP levels compared to increases in the control group.
Previous findings from the HOPE study showed exercise improved AI-associated joint pain, but results from this analysis of favorable decreases in body weight, fat and CRP found these markers did not facilitate the beneficial effect of exercise on AI joint pain.
Further HOPE analyses will be conducted to determine the mechanism(s) of how exercise improves AI joint pain.
Source: Yale Cancer Center