Updating the role of obesity and cholesterol in breast cancer

Abstract

Background: Breast cancer is the second most common cause of cancer-related death among women. Advances in our understanding of the disease have translated into better diagnostics and more effective therapeutics, leading to earlier detection and improved outcomes. Several studies have pointed at lifestyle and environmental factors as contributory for the onset and progression of the disease. Obesity and cholesterol stand out for their potential causal relationship with breast cancer and ease of modification.

Main text: Obesity and cholesterol represent risk factors for breast cancer, but their impact is largely affected by cofounding variables including menopausal status, disease subtype, and inflammation. Establishing a causal relationship between lifestyle factors and clinical outcomes may be challenging. Epidemiological studies and meta-analyses have rendered conflicting or sometimes contradictory results, possibly owing to the multifactorial nature of the disease. We discuss the supporting evidence and limitations in our understanding of obesity and cholesterol as risk factors for breast cancer.

Conclusions: There is sufficient evidence that obesity and cholesterol impact clinical outcomes. Physicians are advised to take steps to help patients with their weight, such as recommending dietary and lifestyle interventions.

Keywords: Estrogen; Inflammation; Lifestyle factors; Menopause; Progesterone; White adipose tissue.

Fig. 1

Schematic representation of the molecular relationship between obesity, inflammation, cholesterol, and breast cancer. NFkB—nuclear factor kappa-light-chain-enhancer of activated B cells; TNFα—tumor necrosis factor alpha; IL—interleukin; PGE2—prostaglandin E2; WAT—white adipose tissue; CLS—crown-like structures; 27-OHC—27 hydroxycholesterol; E2—estradiol