According to a study led by scientists at Duke University Medical Center women receiving care for breast cancer may have significantly impaired cardio-pulmonary function that can persist for years after they have completed treatment.
The findings, reported in the Journal of Clinical Oncology, also provide initial evidence that poor cardio-pulmonary function may be a strong predictor of survival among women with advanced breast cancer.
“We know that exercise tolerance tests, which measure cardiopulmonary function, are among some of the most important indicators of health and longevity in people who do not have cancer; however, relatively little research has been done assessing the clinical importance of these tests in patients with cancer,” said Lee Jones, PhD, associate professor at Duke and lead author of the study.
“Our work provides initial insights into the effects a cancer diagnosis and subsequent therapy may have on how the heart, lungs and rest of the body work together during exercise.”
Dr. Jones is joined in the study by additional authors from Duke University, the University of Alberta in Canada, the University of North Carolina at Chapel Hill, and the NASA Johnson Space Center.
Read Dr. Keith Block’s Mind Over Cancer
The researchers found that women with breast cancer, regardless of treatment status, had significantly worse cardio-pulmonary function than healthy women of the same age who were sedentary. Even among patients who had completed cancer therapy years previously, cardiopulmonary function levels were markedly impaired, suggesting that fitness levels may not recover after therapy.
Approximately a third of women in the study had a cardiopulmonary function score below the threshold that suggests people can function independently – do household tasks, walk up and down stairs, or walk a half mile.
More by Dr. Block: How Diet Affects Cancer
Among the patients with advanced breast cancer, median survival was significantly longer for women with higher cardiopulmonary function. Median survival was 36 months in high-fitness patients vs. 16 months in the low-fitness patients.
“Fitness level may be an important biomarker of survival among cancer patients,” Jones said. “But the beautiful thing about fitness is that we can improve it with exercise training. Although we currently do not know if improving fitness in cancer patients is associated with longer survival, our data provides initial evidence to pursue this question.”
Jones said the findings of this study indicate that exercise may be a good intervention for cancer patients both during and after therapy. His team at Duke University Medical Center has several studies underway examining the effects of exercise training on women with breast cancer, plus patients with other cancers.
Journal of Clinical Oncology, Published online before print May 21, 2012, doi: 10.1200/JCO.2011.39.9014 “Cardiopulmonary Function and Age-Related Decline Across the Breast Cancer Survivorship Continuum”, Lee W. Jones, Whitney E. Hornsby, April D. Coan, James E. Herndon II, and Pamela S. Douglas, Duke University Medical Center, Durham; Hyman B. Muss, University of North Carolina at Chapel Hill, Chapel Hill, NC; Kerry S. Courneya, John R. Mackey, Edith N. Pituskin, and Mark Haykowsky, University of Alberta, Edmonton, Alberta, Canada; and Jessica M. Scott, NASA Johnson Space Center, Houston, TX.
Jones is supported by grants from the National Institutes of Health.