The Insulin-like Growth Factor Axis, Adipokines, Physical Activity, and Obesity in Relation to Breast Cancer Incidence and Recurrence

Abstract

BackgroundObesity, a risk factor for the development of postmenopausal breast cancer and certain other cancer types, has also been associated with poorer response to cancer therapy and cancer recurrence. The insulin-like growth factor (IGF) axis also influences cancer risk.MethodsIn this commentary, we consider the literature on IGF and its binding proteins and the risk of breast cancer, along with effects of obesity, adipokines, and insulin resistance on breast cancer, and the potential for lifestyle interventions to address weight gain and physical inactivity among at-risk women.ResultsGreater body fatness is associated with a higher risk of postmenopausal breast cancer. The association may be explained, in part, by hyperinsulinemia and alterations in adipokines and estrogens. Nutrition, energy balance, and levels of physical activity are determinants of IGF bioactivity. Alterations in the IGF axis can increase cancer risk and progression. Results from epidemiologic studies indicate that higher circulating levels of IGF-I are associated with an increased risk of breast cancer.ConclusionsIntervention studies are needed to determine how to sustain the positive effects of exercise over time and to identify the optimal mode, intensity, frequency, duration, and timing of exercise for breast cancer survivors, including important subgroups of survivors such as African American and Hispanic women. Future epidemiologic studies of the relationships between the IGF axis and breast cancer should include adequate numbers of African American women, Hispanic women, and other minority women who have been underrepresented in studies completed to date.

Towards research-tested smartphone applications for preventing breast cancer

“…Evidence from epidemiologic studies indicates that high levels of physical activity reduce breast cancer risk in women. The possible biological mechanisms include the influences of physical activity on body composition, insulin resistance, and circulating levels of sex steroid hormones (17). Eating non-starchy vegetables may also lower the risk of some breast cancers.…”

Development of the Physical activity and Your Nutrition for Cancer (PYNC) smartphone app for preventing breast cancer in women

“…Evidence from epidemiologic studies indicates that high levels of physical activity reduce breast cancer risk in women (8). The possible biological mechanisms include the influences of physical activity on body composition, insulin resistance and circulating levels of sex steroid hormones (9).…”

The association between treatment for metabolic disorders and breast cancer characteristics.

“…As expected, there were correlations between the intensity of ER and PR IHC staining and the Oncotype ER, PR, and HER2 (according to RT-PCR results, < 0.0001 for all variables). Median ODX RS was 17 (range 0-88) and 50.4%, 38.4%, and 11.2% of the patients had low (0-17), intermediate (18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30), and high (≥31) RS, respectively. (Figure 1) and more intense ER staining (mean 2.59 ± 0.4 versus 2.46 ± 0.58, = 0.032).…”

“…As hyperinsulinemia and insulin-like growth factors were reported to have mitogenic effect on breast cells [17,18], metformin may favorably affect patients with breast cancer. Many in vitro and in vivo studies found that metformin inhibits cancer cell growth, reduces the risk of developing solid tumors, and improves cancer outcome, including breast cancer [11,[19][20][21][22][23].…”