Physical activity helps breast cancer patients survive
Physical activity has been known to reduce breast cancer risk. A new study suggests post-diagnosis physical activity can also drastically reduce risk of death from breast cancer.
The study published in the April 22, 2010 issue of Medical Oncology showed that post-diagnosis physical activity reduced breast mortality by 34 percent. Additionally, physical activity reduced mortality in general by 41 percent.
For the study, Ibrahim E. M. and Al-Homaidh A. from International Medical Center in Kingdom of Saudi Arabia, meta-analyzed data from six studies of 12,108 patients with breast cancer.
The researchers found pre-diagnosis physical activity did not reduce breast cancer death risk, but it did reduce all causes of mortality by 18 percent.
Body mass index made some difference. Prediagnosis physical activity reduced breast Cancer mortality in women with body mass index less than 25 kg/m2, while post-diagnosis physical activity reduced the risk in those whose BMI was greater than 25 kg/m2. Post-diagnosis physical activity reduced all causes of mortality, regardless of BMI status.
Post-diagnosis physical activity also reduced the risk of disease recurrence by 24 percent.
Among patients with estrogen receptor (ER) - positive tumor, post-diagnosis physical activity reduced breast cancer deaths by 50 percent and all causes of mortality by 64 percent, while it did not have an effect on women with ER-negative disease.
The researchers concluded that physical activity increases breast cancer survival.
One study, led by M.W. Dewhirst and colleagues from Duke University Medical Center,explains why exercise could reduce risk of breast cancer and all-cause mortality in patients with diagnosed breast cancer.
Dewhirst et al. implanted human breast cancer cells in mice,and then compared tumor growth in one physically active group with another, sedentary control group.
They found breast cancer growth was comparable in both the exercise and sedentary groups.
However, physiological functions such as blood perfusion and vascularization were improved in the exercise group compared to the sedentary group.
Physical activity or exercise is just one way to help prevent breast cancer. Many other factors may also affect of breast cancer risk. For instance, high levels of plasma vitamin D may help reduce breast cancer risk by up to 70 percent.
Breast cancer is diagnosed in more than 170,000 women each year in the United States; the disease kills about 50,000 annually in the country, according to the National Cancer Institute.
David Liu and editing by Rachel Stockton