Prostate cancer is one of the most common cancers in men and early treatment is usually very successful. However, like other cancers, obesity increases the risk of aggressive prostate disease. New research, published in BioMed Central’s open access journal BMC Medicine, finds that the fat surrounding the prostate of overweight or obese men with prostate cancer provides a favorable environment to promote cancer growth. Fat is a generally underrated organ. Not only is it an energy store but it secretes a wide range of growth factors, cytokines and hormones, including leptin and adiponectin, and is a major player in the immune system, which protects the body from infection and disease. But too much fat can cause these systems to go haywire and can increase risk of diabetes, cardiovascular disease and cancer.