TY - JOUR
T1 - Obesity and its impact on breast cancer
T2 - tumor incidence, recurrence, survival, and possible interventions
AU - Ligibel, Jennifer A.
AU - Strickler, Howard D.
PY - 2013
Y1 - 2013
N2 - A positive association between obesity and the risk of incident postmenopausal breast cancer has been consistently observed in epidemiologic studies. Although most studies of premenopausal women have not found a similar relationship between breast cancer and obesity, the prognosis for both pre- and postmenopausal breast cancer is substantially worse among obese than normal-weight individuals. Increasing evidence suggests that these associations may be mechanistically related to sex hormones, insulin, and certain adipokines. Insulin, for example, has important mitogenic/antiapoptotic activity in addition to its metabolic effects, and many breast tumors express high levels of the insulin receptor (IR)-A isoform. Further, the use of metformin, a diabetes medication that reduces insulin levels, has been epidemiologically associated with reduced breast cancer risk among patients with diabetes, and a recent observational study found a higher rate of pathologic complete responses among patients with diabetes and breast cancer who were using metformin. Formal clinical trials of metformin as adjuvant breast cancer therapy have been initiated and are ongoing. Similarly, the effect of lifestyle changes on breast cancer outcomes is actively being investigated. Several lifestyle intervention studies have demonstrated that weight loss, increased physical activity, and dietary changes are feasible in breast cancer populations, and that individuals who make lifestyle changes after breast cancer diagnosis experience several physical and psychologic benefits. In this article, the authors review the evidence linking obesity with breast cancer risk and outcomes and provide an overview of lifestyle intervention studies in patients with breast cancer.
AB - A positive association between obesity and the risk of incident postmenopausal breast cancer has been consistently observed in epidemiologic studies. Although most studies of premenopausal women have not found a similar relationship between breast cancer and obesity, the prognosis for both pre- and postmenopausal breast cancer is substantially worse among obese than normal-weight individuals. Increasing evidence suggests that these associations may be mechanistically related to sex hormones, insulin, and certain adipokines. Insulin, for example, has important mitogenic/antiapoptotic activity in addition to its metabolic effects, and many breast tumors express high levels of the insulin receptor (IR)-A isoform. Further, the use of metformin, a diabetes medication that reduces insulin levels, has been epidemiologically associated with reduced breast cancer risk among patients with diabetes, and a recent observational study found a higher rate of pathologic complete responses among patients with diabetes and breast cancer who were using metformin. Formal clinical trials of metformin as adjuvant breast cancer therapy have been initiated and are ongoing. Similarly, the effect of lifestyle changes on breast cancer outcomes is actively being investigated. Several lifestyle intervention studies have demonstrated that weight loss, increased physical activity, and dietary changes are feasible in breast cancer populations, and that individuals who make lifestyle changes after breast cancer diagnosis experience several physical and psychologic benefits. In this article, the authors review the evidence linking obesity with breast cancer risk and outcomes and provide an overview of lifestyle intervention studies in patients with breast cancer.
UR - http://www.scopus.com/inward/record.url?scp=84888434121&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84888434121&partnerID=8YFLogxK
U2 - 10.1200/EdBook_AM.2013.33.52
DO - 10.1200/EdBook_AM.2013.33.52
M3 - Review article
C2 - 23714455
AN - SCOPUS:84888434121
SN - 1548-8756
SP - 52
EP - 59
JO - American Society of Clinical Oncology educational book / ASCO. American Society of Clinical Oncology. Meeting
JF - American Society of Clinical Oncology educational book / ASCO. American Society of Clinical Oncology. Meeting
ER -