Typical features of the breast malignant phenotype rely on metabolic reprogramming of cancer cells and their interaction with surrounding adipocytes. Obesity is strongly associated with breast cancer mortality, yet the effects of obesity on metabolic reprogramming of cancer and cancer-associated adipose tissue remain largely unknown. Paired biopsies of breast tumor tissue and adipose tissue from premenopausal women were divided according to pathohistological analyses and body mass index on normal-weight and overweight/obese with benign or malignant tumors. We investigated the protein expression of key regulatory enzymes of glycolysis, pentose phosphate pathway (PPP), and glycogen synthesis. Breast cancer tissue showed a simultaneous increase in 5′-AMP-activated protein kinase (AMPK) protein expression with typical features of the Warburg effect, including hexokinase 2 (HK 2) overexpression and its association with mitochondrial voltage-dependent anion-selective channel protein 1, associated with an overexpression of rate-limiting enzymes of glycolysis (phosphofructokinase 1—PFK-1) and pentose phosphate pathway (glucose-6-phosphate dehydrogenase—G6PDH). In parallel, cancer-associated adipose tissue showed increased AMPK protein expression with overexpression of HK 2 and G6PDH in line with increased PPP activity. Moreover, important obesity-associated differences in glucose metabolism were observed in breast cancer tissue showing prominent glycogen deposition and higher glycogen synthase kinase-3 protein expression in normal-weight women and higher PFK-1 and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) protein expression in overweight/obese women. In conclusion, metabolic reprogramming of glycolysis contributes to tissue-specific Warburg effect in breast cancer and cancer-associated adipose tissue.

Metabolic reprogramming that favors high glycolytic flux with lactate production in normoxia is among cancer hallmarks. Lactate is an essential oncometabolite regulating cellular redox homeostasis, energy substrate partitioning, and intracellular signaling. Moreover, malignant phenotype’s chief characteristics are dependent on the interaction between cancer cells and their microenvironment. In breast cancer, mammary adipocytes represent an essential cellular component of the tumor milieu. We analyzed lactate concentration, lactate dehydrogenase (LDH) activity, and isozyme pattern, and LDHA/LDHB protein expression and tissue localization in paired biopsies of breast cancer tissue and cancer-associated adipose tissue in normal-weight and overweight/obese premenopausal women, compared to benign breast tumor tissue and adipose tissue in normal-weight and overweight/obese premenopausal women. We show that higher lactate concentration in cancer tissue is concomitant with a shift in isozyme pattern towards the “muscle-type” LDH and corresponding LDHA and LDHB protein expression changes. In contrast, significantly higher LDH activity in cancer-associated adipose tissue seems to be directed towards lactate oxidation. Moreover, localization patterns of LDH isoforms varied substantially across different areas of breast cancer tissue. Invasive front of the tumor showed cell-specific protein localization of LDHA in breast cancer cells and LDHB in cancer-associated adipocytes. The results suggest a specific, lactate-centric relationship between cancer tissue and cancer-associated adipose tissue and indicate how cancer-adipose tissue cross-talk may be influenced by obesity in premenopausal women.

The close cooperation between breast cancer and cancer-associated adipose tissue (CAAT) shapes the malignant phenotype, but the role of mitochondrial metabolic reprogramming and obesity in breast cancer remains undecided, especially in premenopausal women. Here, we examined mitochondrial metabolic dynamics in paired biopsies of malignant versus benign breast tumor tissue and CAAT in normal-weight and overweight/obese premenopausal women. Lower protein level of pyruvate dehydrogenase and citrate synthase in malignant tumor tissue indicated decreased carbon flux from glucose into the Krebs cycle, whereas the trend was just the opposite in malignant CAAT. Simultaneously, stimulated lipolysis in CAAT of obese women was followed by upregulated β-oxidation, as well as fatty acid synthesis enzymes in both tumor tissue and CAAT of women with malignant tumors, corroborating their physical association. Further, protein level of electron transport chain complexes was generally increased in tumor tissue and CAAT from women with malignant tumors, respective to obesity. Preserved mitochondrial structure in malignant tumor tissue was also observed. However, mitochondrial DNA copy number and protein levels of PGC-1α were dependent on both malignancy and obesity in tumor tissue and CAAT. In conclusion, metabolic cooperation between breast cancer and CAAT in premenopausal women involves obesity-related, synchronized changes in mitochondrial metabolism.

Digit ratio established in utero is positivelly correlated with intrauterine level of estrogen. Since the breast cancer is related to excessive and prolonged exposure to estrogen, digit ratio might be considered as useful marker in breast cancer risk assessment. The aim of the present study was to compare digit ratios in breast cancer patients and healthy controls. The study group consisted of 98 breast cancer patients aged between 29 to 84 years while the control group included 141 healthy women aged between 21 and 67 years. After collecting anamnestic data concerning menopausal status, the length of second and fourth fingers were measured and the digit ratios were calculated for both hands, as well as the difference between right and left digit ratio. Digit ratio was significantly higher on right hand in breast cancer patients compaired to healthy controls (1.003±0.05 vs. 0.990±0.03). Right digit ratio showed better predictive capacity for the breast cancer development then the left (AUC:0.609 vs. 0.541). Negative statistically significant correlation between right digit ratio and the age of breast cancer diagnosis was observed (r=-0.271). Higher values of right digit ratio in women with breast cancer when compared to healthy women suggest their higher prenatal estrogen exposure that confirms the importance of digit ratio determination in breast cancer risk assessment.

Inconsistent data are available on the relation between breast cancer, adiposity, body size and somatotype. The aim of our study was to compare anthropometric characteristics, body composition and somatotype between breast cancer patients and healthy controls. Study group consisted of 106 breast cancer patients while control group consisted of 100 healthy women who underwent 29 anthropometric measurements. Women with breast cancer expressed more male anthropometric features like higher stature (160.75±6.91 vs. 158.17±4.89 cm, p=0.020), shorter trunk (sitting height in premenopausal: 84.94±5.07 vs. 88.50±3.84 cm, p=0.001 and postmenopausal women: 81.96±6.08 vs. 85.19±3.36 cm, p=0.001), narrower hips (29.20±3.78 vs. 32.24±1.78 cm, p=0.000), higher biepicondylar diameter of humerus (premenopausal: 6.64±0.71 vs. 6.31±0.42 cm, p=0.012; postmenopausal: 6.95±0.63 vs. 6.54±0.49 cm, p=0.000), larger upper- and forearm as well as upper thigh circumferences followed by lower biceps and higher thigh skinfold thicknesses. They also had significantly lower endomorphy (premenopausal: 5.84±1.78 vs. 6.55±0.96, p=0.027; postmenopausal: 6.89±1.52 vs. 7.37±0.86, p=0.035) and significantly higher ectomorphy (premenopausal: 2.05±1.30 vs. 1.41±0.99, p=0.018; postmenopausal: 1.06±0.90 vs. 0.68±0.56, p=0.007), as well as higher mesomorphy only in postmenopausal women (6.10±2.04 vs. 5.37±1.34, p=0.022). Most represented somatotype among breast cancer patients was endomorph-mesomorph while the most healthy controls were mesomorphic endomorph. Android body type increases the risk of development of breast cancer. Indicators of skeletal dimensions, muscle volume and peripheral adiposity had better predictive value over markers of central and overall adiposity.

Breast cancer is one of the most common malignant diseases in women worldwide. Since the involvement of axillary lymph node metastases is related to the poor prognosis of these patients, the objective of our study was to investigate the association between breast tumor size and the presence of axillary lymph node metastases. Our research was performed at the Institute of Oncology of Vojvodina in Sremska Kamenica. The study consisted of 72 women diagnosed with breast cancer aged between 29 and 84 years (average age: 59.04±10.87 years) whose breast tumor was surgically removed at the Institute of Oncology of Vojvodina. Patients who received preoperative chemo- or radiotherapy were excluded from the study. The data concerning breast tumor size and the presence of axillary lymph nodes in these women was obtained from the reports of Department of Pathoanatomical Diagnostics of the Institute of Oncology of Vojvodina. The results of our study indicated to positive, statistically significant moderate correlation between the size of breast tumor and the presence of axillary lymph node metastases (r=0.32, p=0.01). Receiver operating curve (ROC) analysis notified that cut-off value of breast tumor size for the presence of axillary lymph node metastasis was 22.5 mm (AUC=0.70, p=0.01). In our investigation, women with breast tumor size of 22.5 mm or larger were predisposed to the presence of axillary lymph node metastases. This research was supported by the Science Fund of the Republic of Serbia, #7750238, Exploring new avenues in breast cancer research: Redox and metabolic reprogramming of cancer and associated adipose tissue - REFRAME.