Peer Counseling for Weight Loss in African American Breast Cancer Survivors

Trial Information

Peer Counseling for Weight Loss in African American Breast Cancer Survivors

Obesity has adverse effects on breast cancer survival and recurrence, and this may be
mediated via the insulin resistance that is associated with obesity. This is a matter of
exceptional concern for African-American (AA) breast cancer survivors since a greater
proportion of AAs than European Americans (EA) are obese, insulin-resistant and diabetic.
This proposal seeks to test the effects of weight loss intervention in obese and overweight
AA breast cancer survivors (body mass index 25-40 kg/m2, stage I, II, or IIIA cancer, free
of recurrence). Subjects (n=100) will be randomized across 3 arms: 1) control; 2)
individualized, dietitian-led counseling; and 3) dietitian-led counseling combined with peer
counseling using telephone counseling by trained peers who are AA breast cancer survivors
successful at weight control. Psychosocial factors that can affect the extent of weight loss
achieved will be assessed, including individual, home and community-level factors. Some of
these factors may change when weight loss is achieved and will be assessed both before and
after intervention. Genetic polymorphisms that have been shown to be associated with
increased body weight, insulin resistance, lipid metabolism, and oxidative stress will be
determined and related to both baseline and post-intervention anthropometric and biologic
measures. This should further help elucidate inter-individual differences in response to
weight loss intervention. The possible beneficial effects of weight loss on the health
risks associated with obesity will be evaluated with measures of insulin resistance,
insulin-like growth factor and lipid levels in blood samples, as well as with blood pressure
and anthropometric measures. The effects of weight loss on these measures have been studied
in other obese and overweight populations, but there is little data in breast cancer
survivors. Finally, we will attempt to determine if beneficial effects of weight loss can
be detected in the breast, since this should be related to subsequent breast cancer risk.
The breast contralateral to surgery will be subjected to ductal lavage at baseline, 12 and
24 months. The investigators will examine the effects of weight change on markers of
oxidative stress in the breast nipple aspirate fluid that is obtained as part of the lavage
procedure. Levels of lipid peroxidation are very high in this fluid and have been related
to both nuclear atypia and breast cancer risk. The nuclear morphology of epithelial cells
obtained by ductal lavage therefore will be quantified as well. Weight loss in obese and
overweight AA breast cancer survivors should improve both psychosocial function and
biological indicators of health risks.