Breast cancer patients who do not get sufficient exercise may compromise quality of life and ultimately, survival, according to a new study from researchers at the Department of Epidemiology, University of North Carolina at Chapel Hill, NC.
The study, published in the online peer-reviewed publication of the American Cancer Society, Cancer, indicates a need for significant enhancements to promote and encourage participation in physical activity to breast cancer patients during and beyond treatment.
Current estimates for new cases of invasive breast cancer in the US are around 232,670 for 2014. Except for skin cancers, breast cancer is the most common cancer among American women and the second leading cause of death. There are currently more than 2.8 million breast cancer survivors in the US, both those being treated and those who have completed treatment.
The American Cancer Society emphasizes the importance of exercise after breast cancer surgery, to help restore movement and involvement in usual activities.
Many women with breast cancer have procedures such as breast biopsy, lymph node biopsy or removal, lumpectomy, mastectomy or breast reconstruction. Exercise plays an essential part in regaining flexibility, particularly of arm and shoulder movement and can gently be introduced 3 to 7 days after surgery and during radiation therapy.
Phase 3 of the Carolina Breast Study is a population-based survivorship cohort study based in 44 counties in eastern and central North Carolina between 2008 and 2011. Participation was limited to female English-speakers newly diagnosed with invasive breast cancer, aged 20-74 years. Research reflects data collected at the baseline interview, conducted around 6 months after diagnosis.
The researchers, including Brionna Hair, a doctoral candidate in epidemiology at the University, examined levels of and changes in physical activity following breast cancer diagnosis, by race.
Levels of vigorous-intensity (i.e., running and heavy yard work) and moderate-intensity exercise (i.e., brisk walking, vacuuming and gardening) that participants had completed within 3 months previous to breast cancer diagnosis and the 7 days previous to the baseline interview were noted.
Assessment was also made of the total number of weekly minutes of physical activity and changes in physical activity levels between pre-diagnosis and post-diagnosis.
The sampling weights comprised of African-American women aged under 50 years, African-American women aged 50 years or over, non-African-American women aged under 50 years, and non-African-American women aged 50 years or over.
The Office of Disease Prevention and Health Promotion (ODPHP), within the US Department of Health and Human Services (HHS), led the development of the first ever Physical Activity Guidelines for Americans in 2008. The guidelines affirm that for substantial health benefits, adults should do at least 150 minutes (2 hours and 30 minutes) a week of moderate-intensity, or 75 minutes (1 hour and 15 minutes) a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity.
Only 35% of patients involved in the study met current physical activity guidelines after breast cancer diagnosis.
Pre-diagnosis and post-diagnosis assessment of activity levels in 1,735 women, 48% of which were African-American, demonstrated a weekly reduction in physical activity of 15 metabolic equivalent task (MET) hours per week (95% CI, 12 MET hours-19 MET hours), postdiagnosis – equivalent to about 5 hours per week of brisk walking. After diagnosis, 59% of patients reported decreased physical activity.
African-American women, when compared with white women, reported lower levels of physical activity pre-diagnosis. African-American women were about 40% less likely to meet national physical activity guidelines post-diagnosis when compared with white women.
The majority of participants reported a decline in physical activity after diagnosis. However, findings also suggested that approximately 1 in 5 women increased their activity levels by at least 30 minutes per week after being diagnosed with breast cancer.
“Medical care providers should discuss the role physical activity plays in improving breast cancer outcomes with their patients, and strategies that may be successful in increasing physical activity among breast cancer patients need to be comprehensively evaluated and implemented.”
Mortality rate is reduced by 34% after breast cancer diagnosis for individuals with higher levels of reported physical activity, compared with those with the least amount of physical activity.
Suggestions have been made formally to incorporate exercise needs into the care of women with breast cancer. The evidence that physical activity post-diagnosis improves quality of life and survival needs to be translated into practice, especially among African-American women who experience higher mortality from breast cancer than other groups in the US.
Medical News Today recently presented a feature on what science is doing to improve the health and lives of cancer survivors. Currently, the number of cancer survivors in the US is estimated to be 14.5 million. Among women survivors, the three most common cancers are breast (41%), uterine (8%) and colorectal (8%).