Obesity is associated with an increased risk of
breast cancer, which is the most common
cancer in women worldwide (excluding non-
melanoma skin cancer). Furthermore,
breast cancer patients with
obesity have an impaired prognosis. Adipose tissue is abundant in the breast. Therefore,
breast cancer develops in an adipose-rich environment. During
obesity, changes in the local environment in the breast occur which are associated with
breast cancer. A shift towards a pro-inflammatory state is seen, resulting in altered levels of
cytokines and immune cells. Levels of
adipokines, such as
leptin,
adiponectin, and
resistin, are changed.
Aromatase activity rises, resulting in higher levels of potent
estrogen in the breast. Lastly, remodeling of the extracellular matrix takes place. In this review, we address the current knowledge on the changes in the breast adipose tissue in
obesity associated with
breast cancer initiation and progression. We aim to identify
obesity-associated
biomarkers in the breast involved in the interplay between
obesity and
breast cancer. Hereby, we can improve identification of women with
obesity with an increased risk of
breast cancer and an impaired prognosis. Studies investigating mammary adipocytes and breast adipose tissue in women with
obesity versus women without
obesity are, however, sparse and further research is needed.