RESUMEN
Worldwide, breast cancer is the most frequently diagnosed life-threatening cancer in women and the most important cause of cancer-related deaths among women. This disease is on the rise in Turkey. Metabolic syndrome is a cluster of metabolic disturbances including insulin resistance, dyslipidemia, hypertension, abdominal obesity and high blood sugar. Several studies have examined the association of the individual components of the metabolic syndrome with breast cancer. More recent studies have shown it to be an independent risk factor for breast cancer. It has also been associated with poorer prognosis, increased incidence, a more aggressive tumor phenotype. Basic research studies are now in progress to illuminate the molecular pathways and mechanisms that are behind this correlation. Given the fact that all of the components of metabolic syndrome are modifiable risk factors, preventive measures must be established to improve the outcome of breast cancer patients. In this review we set the background by taking into account previous studies which have identified the components of metabolic syndrome individually as breast cancer risk factors. Then we present the latest findings which elaborate possible explanations regarding how metabolic syndrome as a single entity may affect breast cancer risk.