Risk Reduction from Weight Management and Physical Activity Interventions

Abstract

Obesity and low levels of physical activity are associated with a higher risk of breast cancer recurrence and mortality. Currently, over 65% of breast cancer survivors are overweight or obese, and fewer than 30% engage in recommended levels of physical activity. The reason for low adherence to lifestyle guidelines is likely multifactorial. Given the continuing trend of increased obesity and physical inactivity in the United States, worldwide and in breast cancer survivors, more research showing the direct effect of weight loss and/or exercise on breast cancer recurrence and mortality is needed. Many exercise interventions have examined the impact of increasing exercise on changes in quality of life, with most studies showing a favorable effect of exercise on quality of life. Smaller Phase II randomized trials using biomarkers as surrogate endpoints is likely appropriate to answer questions regarding mechanisms of action, exercise type, volume, and intensity, yet a definitive trial of weight loss and exercise on disease-free survival is critical for moving the field forward. Research is also necessary on how to disseminate lifestyle interventions into the clinic and community that lead to clinically meaningful weight losses of at least 5% that are maintained over time, and favorable sustained changes in physical activity levels. Changes in referrals, access, and reimbursement of lifestyle programs may lead to favorable changes in the prevalence of obesity and physical activity in breast cancer survivors and in turn rates of breast cancer recurrence and mortality.

Endometrial cancer and obesity

“…Studies in breast cancer have shown that weight loss reduces markers of recurrence, including total and free estradiol, insulin, adiponectin and inflammatory and cancer-promoting proteins. 62,63 Few studies have investigated the benefits of weight loss following treatment for endometrial cancer and all have had limited follow up, been underpowered to examine the effect of the intervention on survival and used diet and exercise regimes that failed to achieve substantial weight loss. 64 Only one RCT reported survival at 24 months and found no improvement in overall survival with a lifestyle and behavioural intervention.…”

Beliefs and Behaviors about Breast Cancer Recurrence Risk Reduction among African American Breast Cancer Survivors

“…Maintaining a healthy weight [ 18 , 19 ], performing physical activity [ 19 , 20 , 21 ], reducing dietary fat consumption [ 13 ], consuming fruits and vegetables [ 19 ], and limiting alcoholic intake [ 14 ] are important lifestyle behaviors that may reduce BC recurrence. Although BC survivors may be aware of the relationship between lifestyle and risk of BC recurrence [ 22 , 23 ], many report poor adherence to cancer prevention strategies aimed at reducing recurrence [ 24 ].…”

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

“…The average reported weight gain is 2.5-5 kg, 5 but a gain of 10 kg or more is not uncommon. 14 The reasons for weight gain are multifactorial and include "stress eating," reduced activity because of fatigue or other treatment-related adverse effects, lowered metabolic rate from chemotherapy, and use of pre-and post-chemotherapy medications such as dexamethasone. 14 Weight gain is most common in women who experience treatment-related menopause and is often accompanied by relative fat gain and muscle loss.…”

“…14 The reasons for weight gain are multifactorial and include "stress eating," reduced activity because of fatigue or other treatment-related adverse effects, lowered metabolic rate from chemotherapy, and use of pre-and post-chemotherapy medications such as dexamethasone. 14 Weight gain is most common in women who experience treatment-related menopause and is often accompanied by relative fat gain and muscle loss. 15 Several observational studies have shown that gaining weight during or after breast cancer treatment increases the risk of recurrence and reduces survival, irrespective of baseline body mass index (BMI).…”