Obesity Impact on Managing Aromatase Inhibitors Side Effects in Breast Cancer Patients

OBJECTIVES: Because the main aromatase inhibitors side effects are osteoporosis and dyslipidemia, vitamin D, calcium dietary supplements and statins are frequently co-administered alongside the antiestrogenic treatment. Does this common clinical practice have scientific arguments behind it? METHODS: The scientific literature available since 2000 addressing the efficacy of vitamin D, calcium dietary supplements and statins in preventing osteoporosis and dyslipidemia was searched and efficacy randomized controlled trials, meta-analysis and systematic reviews results are further reported. RESULTS: The current scientific data on cardiovascular disease shows that successfully achieved lowered LDL-cholesterol does not associate lowered mortality, the difference in survival between people with high cardiovascular risk who take statins compared to those who do not take statins being only 4 days. Furthermore, taking vitamin D supplements for cardiovascular protection or for cancer prevention for that matter is a recommendation unsupported by the current scientific literature. Also, the current scientific data on osteoporosis prevention shows that the prophylactic prescription of vitamin D and calcium dietary supplements in patients without objectively proven deficiencies does not prevent osteoporosis, increasing fractures risk. Aromatase inhibitors side effects are highly influenced by patient's adiposity. Current data shows that obesity increases cardiovascular risk, and that obese patients have lower vitamin D blood levels because of its deposition inside the fat tissue, vitamin D levels going back up to normal without supplements when adiposity decreases. CONCLUSIONS: Obesity decreases statins, vitamin D and calcium dietary supplements efficacy in counteracting AI side effects. But, because of the potential negative metabolic impact of improper diets, weight loss in breast cancer patients under antiestrogenic treatment should be carefully designed and monitored by dietitians with expertise in oncology nutrition. FUNDING SOURCES: None.