Several studies have shown that hormonal, metabolic and inflammatory mechanisms may affect breast cancer progression. We tested the prognostic value of metabolic syndrome in 110 postmenopausal breast cancer patients, who participated in a 1-year dietary intervention study. The risk of adverse events after 5.5 years of follow-up was examined by Cox' proportional hazard modelling, adjusting for hormone receptor status, stage at diagnosis and serum testosterone level, which were shown to significantly affect prognosis. The adjusted hazard ratio of recurrence for the presence of metabolic syndrome at baseline was 3.0 (95% CI 1.2-7.1). Combining metabolic syndrome and serum testosterone, the adjusted hazard ratio of recurrence among women with metabolic syndrome and testosterone levels higher than 0.40 ng/ml (median value) was 6.7 (95% CI 2.3-19.8) compared with that among women without metabolic syndrome and testosterone levels 0.40 ng/ml. The results suggest that metabolic syndrome may be an important prognostic factor for breast cancer. ' 2006 Wiley-Liss, Inc.Key words: breast cancer; recurrences; metabolic syndromeThe prevalence of metabolic syndrome is increasing in parallel with increasing breast cancer incidence worldwide. 1,2 Several studies have suggested that low HDL-cholesterol, 3 high blood glucose, 4 high triglycerides 5 and other aspects of the metabolic syndrome, such as postmenopausal overweight, 1 abdominal obesity, 6,7 hypertension, 8 high levels of insulin and insulin-like growth factor I (IGF-I), 7,9-11 are associated with breast cancer risk. Metabolic and hormonal parameters related to metabolic syndrome have been suggested to affect breast cancer prognosis too. [12][13][14][15] This is the first report addressing the issue whether breast cancer prognosis is affected by metabolic syndrome, defined by 3 or more of the following indicators: fasting glycaemia 110 mg/dl, HDL-cholesterol <50 mg/dl, triglycerides 150 mg/dl, waist circumference 88 cm, systolic pressure 130 mmHg and diastolic pressure 85 mmHg. 16 If confirmed, these results showing a significantly worse prognosis of patients with metabolic syndrome could have important implications for lifestyle intervention to prevent or decelerate cancer progression. Patients and methodsOne hundred and ten postmenopausal women (mean age: 56.8 6 5.6 years) operated for breast cancer since at least a year (4.6 6 4.4 years on average), not undergoing chemotherapy, and with no clinical evidence of disease recurrence, volunteered to participate in a dietary intervention study in which they were requested to follow kitchen courses and modify their diet for 1 year with the aim of reducing insulin and sex hormone levels (The Diana-2 Study). 12 All patients signed an informed consent and the study was approved by the Institutional Review Board and the Ethical Committee of the Milan National Cancer Institute. Results on hormonal changes and the prognostic values of baseline hormone levels (testosterone, oestradiol and insulin) have been published elsewhere. 12,...

Western lifestyle, characterized by reduced physical activity and a diet rich in fat, refined carbohydrates, and animal protein is associated with high prevalence of overweight, metabolic syndrome, insulin resistance, and high plasma levels of several growth factors and sex hormones. Most of these factors are associated with breast cancer risk and, in breast cancer patients, with increased risk of recurrences. Recent trials have proven that such a metabolic and endocrine imbalance can be favorably modified through comprehensive dietary modification, shifting from Western to Mediterranean and macrobiotic diet.