Exercise for Secondary Prevention of Breast Cancer: Moving from Evidence to Changing Clinical Practice

Abstract

Relating to the report of Irwin and colleagues in this issue of the journal (beginning on page 522), this perspective discusses exercise training interventions as secondary prevention in breast cancer survivors. Burgeoning observational evidence indicates that prescribing aerobic exercise of 3 hours or more per week could have meaningful mortality and morbidity benefits for breast cancer survivors. Adherence to this exercise prescription, however, will require an infrastructure to guide survivors and to address the common clinical treatment sequelae that might interfere with survivors' ability to regularly perform this level of activity (e.g., symptoms related to estrogen deprivation, arthralgias due to aromatase inhibitors, fatigue, lymphedema, chemotherapy-induced peripheral neuropathy, osteoporosis, upper-extremity functional impairments, and overall functional decline). On the basis of cardiac rehabilitation, a model is proposed to integrate exercise prescription into breast cancer survivor clinical care, with referral to community-based programs for most women. Cancer Prev Res; 4(4); 476-80. Ó2011 AACR.The article by Irwin and colleagues appearing elsewhere in this issue of the journal (1) adds to prior strong prospective observational studies demonstrating decreased overall and disease-specific mortality among more versus less physically active breast cancer survivors. A 2010 meta-analysis included 6 prior studies on this topic (2). As with the study of Irwin and colleagues, the meta-analysis analyzed distinct effects of physical activity measured pre-versus postdiagnosis. The meta-analysis summary estimates of the reduction of breast cancer-specific and all-cause mortality for the women who self-reported the most compared to the least pre-diagnosis physical activity were 7% and 18%, respectively. These estimates were based on pooled data from 2 studies each for breast cancer-specific (3, 4) and allcause mortality (3, 5). Irwin and colleagues reported reductions of 29% for breast cancer-specific and 39% for overall mortality among the most-versus least-active women prediagnosis.Unfortunately, physical activity levels decline after diagnosis (6) and functional status remains lower among a substantial minority of breast cancer survivors for over 5 years after diagnosis (7,8). These issues make it difficult to conclude that data on prediagnosis physical activity are relevant for examining the mortality benefit of exercise in survivors. In short, the women who are active before diagnosis may not be able to be active after diagnosis. Therefore, it is of interest to understand whether physical activity after diagnosis confers benefits. In the 2010 metaanalysis, summary estimates based on pooled effects from 4 studies (3, 9-11) showed that breast cancer-specific mortality was reduced 34% and all-cause mortality was reduced 41% for the women who reported being most versus least active postdiagnosis. Irwin and colleagues observed mortality reductions of 39% (breast cancer-specific) and 46% (overall) among w...

Cancer, Physical Activity, and Exercise

“…We are now arriving at the stage of clinical research where the successful translation and implementation of these results into standard clinical practice is needed (135). This next phase of translation and implementation will require the participation of experts in a variety of domains, including medical care and planning, exercise physiology, behavioral science, and implementation science.…”

Toward a National Initiative in Cancer Rehabilitation: Recommendations From a Subject Matter Expert Group

“…60 Ambulatory cancer rehabilitation programs however have wide variance in the service offerings and little consistency as to the timing of intervention, coordination with other medical providers, coordination with the cancer care plan, and follow-up. Adaptation of the cardiac rehabilitation model for use in oncology rehabilitation has been suggested as a model 61,62 because the tenants of cardiac rehabilitation, including rehabilitation, treatment sequelae management, and healthy lifestyle development, 63 are common to oncology rehabilitation. However, limited data are available to support this approach.…”

Lifestyle modifications for patients with breast cancer to improve prognosis and optimize overall health

“…Some experts have recommended having systems in place to refer patients directly from a cancer care clinic to community-based exercise programs specialized for cancer survivors. 66 Although specific exercise interventions can result in strong behavioural changes, providing support to patients by phone or email has also proven effective. 67 Weight gain of more than 10% body weight after a breast cancer diagnosis increases breast cancer mortality and all-cause mortality.…”