Adipose‐Derived Fatty Acid‐Binding Proteins Plasma Concentrations Are Increased in Breast Cancer Patients

BACKGROUND. Adipose tissue is an endocrine organ that could play a role in tumor progression via its secreted adipokines. The role of adipose‐derived fatty acid‐binding protein (FABP) 4 and FABP5 in breast cancer is presently under study, but their circulating levels in this pathology are poorly known. We analyzed the blood concentrations of FABP4 and FABP5 in breast cancer patients to determine whether there is an association between them and breast cancer. MATERIALS AND METHODS. We studied 294 women in the oncology department with a family history of breast cancer; 198 of the women had breast cancer, and 96 were healthy controls. The levels of FABP4, FABP5, lipid profile, standard biochemical parameter, and high‐sensitivity C‐reactive protein (hsCRP) were determined. We analyzed the association of FABP4 and FABP5 with breast cancer, while adjusting for demographic, anthropometric, and biochemical parameters. RESULTS. Breast cancer patients had a 24.8% (p < .0001) and 11.4% (p < .05) higher blood concentration of FABP4 and FABP5, respectively. Fatty acid‐binding protein 4 was positively associated with age, body mass index (BMI), FABP5, very‐low‐density lipoprotein cholesterol (VLDLc), non‐high‐density lipoprote in cholesterol (non‐HDLc), Apolipoprotein B 100 (ApoB100), triglycerides, glycerol, glucose, and hsCRP (p < .05), and was negatively associated with HDLc (p < .005) in breast cancer patients. Fatty acid‐binding protein 5 was positively associated with BMI, FABP4, VLDLc, triglycerides, glycerol, and hsCRP (p < .05), and was negatively associated with HDLc and Apolipoprotein AI (ApoAI) (p < .05) in breast cancer patients. Using a logistic regression analysis and adjusting for age, BMI, hsCRP, non‐HDLc, and triglycerides, FABP4 was independently associated with breast cancer (odds ratio [OR]: 1.091 [95% CI: 1.037–1.149]). Moreover, total cholesterol, VLDLc, non‐HDLc, ApoB100, triglycerides, and hsCRP were significantly increased in breast cancer patients (p < .005). In contrast, the non‐esterified fatty acids concentrations were significantly decreased in breast cancer patients (p < .05). CONCLUSION. Circulating FABP4 and FABP5 levels were increased in breast cancer patients compared with controls. The positive association of FABP4 with breast cancer was maintained after adjusting for important covariates, while the association with FABP5 was lost. Our data reinforce the role of adipose tissue and their adipokines in breast cancer. Despite these data, further studies must be performed to better explain the prognosis or diagnostic value of these blood parameters and their possible role in breast cancer. IMPLICATIONS FOR PRACTICE. We focus on the effect of adipose tissue on cancer, which is increasingly recognized. The association between adipocyte‐derived adipokines and breast cancer opens new diagnosis and therapy perspectives. In this study, we provide original data concerning FABP4 and FABP5 plasma concentrations in breast cancer patients. Compared to control group, breast cancer patients show higher FABP4 and FABP5 blood levels. Our data suggest that, particularly, circulating FABP4 levels could be considered a new independent breast cancer biomarker. Our work translates basic science data to clinic linking the relationship between adipose tissue and lipid metabolism to breast cancer.