Elevated Levels of Serum Biomarkers Associated with Damage to the CNS Neurons and Endothelial Cells Are Linked with Changes in Brain Connectivity in Breast Cancer Patients with Vestibulo-Atactic Syndrome

Vestibulo-atactic syndrome (VAS), which represents a combination of motor and vestibular disorders, can be manifested as a clinical complication of breast cancer treatment and has a significant impact on patients' quality of life. The identification of novel potential biomarkers that might help to predict the onset of VAS and its progression could improve the management of this group of patients. In the current study, the levels of intercellular cell adhesion molecule 1 (ICAM-1), platelet/endothelial cell adhesion molecule 1 (PECAM-1), NSE (neuron-specific enolase), and the antibodies recognizing NR-2 subunit of NMDA receptor (NR-2-ab) were measured in the blood serum of BC survivor patients with vestibulo-atactic syndrome (VAS) and associated with the brain connectome data obtained via functional magnetic resonance imaging (fMRI) studies. A total of 21 patients were registered in this open, single-center trial and compared to age-matched healthy female volunteers (control group) (n = 17). BC patients with VAS demonstrated higher serum levels of ICAM-1, PECAM-1, and NSE and a lower value of NR-2-ab, with values of 654.7 ± 184.8, 115.3 ± 37.03, 49.9 ± 103.9, and 0.5 ± 0.3 pg/mL, respectively, as compared to the healthy volunteers, with 230.2 ± 44.8, 62.8 ± 15.6, 15.5 ± 6.4, and 1.4 ± 0.7 pg/mL. According to the fMRI data (employing seed-to-voxel and ROI-to-ROI methods), in BC patients with VAS, significant changes were detected in the functional connectivity in the areas involved in the regulation of postural-tonic reflexes, the coordination of movements, and the regulation of balance. In conclusion, the detected elevated levels of serum biomarkers may reveal damage to the CNS neurons and endothelial cells that is, in turn, associated with the change in the brain connectivity in this group of patients.

Neurotrophin-3 (NT-3) as a Potential Biomarker of the Peripheral Nervous System Damage Following Breast Cancer Treatment

Damage to the peripheral nervous system (PNS) is a common complication of breast cancer (BC) treatment, with 60 to 80% of breast cancer survivors experiencing symptoms of PNS damage. In the current study, the levels of brain-derived neurotrophic factor (BDNF), galectin-3 (Gal-3), and neurotrophin-3 (NT-3) were measured in the blood serum of BC patients by ELISA as potential biomarkers that might indicate the PNS damage. Sixty-seven patients were enrolled in this multi-center trial and compared to the aged-matched healthy female volunteers (control group) (n = 25). Intergroup comparison of biomarker levels (i.e., Gal-3 and BDNF) did not show significant differences in any of the studied subgroups. However, intriguingly, NT-3 levels were significantly higher in BC patients as compared to healthy volunteers, constituting 14.85 [10.3; 18.0] and 5.74 [4.56; 13.7] pg/mL, respectively (p < 0.001). In conclusion, NT-3 might be employed as a potential biomarker in BC patients with clinical manifestations of PNS damage. However, further studies to validate its correlation to the degree of peripheral nervous system lesions are of high value.

Microstructural Properties of Brain White Matter Tracts in Breast Cancer Survivors: A Diffusion Tensor Imaging Study

Complex breast cancer (BC) treatment can cause various neurological and psychiatric complications, such as postmastectomy pain syndrome, vestibulocerebellar ataxia, and depression, which can lead to microstructural damage of the white matter tracts of the brain. The purpose of the study is to assess microstructural changes in the white matter tracts of the brain in BC survivors using diffusion tensor imaging (DTI). Single DTI scans were performed on patients (n = 84) after complex BC treatment (i.e., surgery, chemotherapy and/or radiation therapy) and on the control group (n = 40). According to the results, a decrease in the quantitative anisotropy (FDR ≤ 0.05) was revealed in the bilateral corticospinal tracts, cerebellar tracts, corpus callosum, fornix, left superior corticostriatal and left corticopontine parietal in patients after BC treatment in comparison to the control group. A decrease in the quantitative anisotropy (FDR ≤ 0.05) was also revealed in the corpus callosum and right cerebellar tracts in patients after BC treatment with the presence of postmastectomy pain syndrome and vestibulocerebellar ataxia. The use of DTI in patients after BC treatment reveals microstructural properties of the white matter tracts in the brain. The results will allow for the improvement of treatment and rehabilitation approaches in patients receiving treatment for breast cancer.

Potential Molecular Biomarkers of Central Nervous System Damage in Breast Cancer Survivors

Damage of the central nervous system (CNS), manifested by cognitive impairment, occurs in 80% of women with breast cancer (BC) as a complication of surgical treatment and radiochemotherapy. In this study, the levels of ICAM-1, PECAM-1, NSE, and anti-NR-2 antibodies which are associated with the damage of the CNS and the endothelium were measured in the blood by ELISA as potential biomarkers that might reflect pathogenetic mechanisms in these patients. A total of 102 patients enrolled in this single-center trial were divided into four groups: (1) 26 patients after breast cancer treatment, (2) 21 patients with chronic brain ischemia (CBI) and asymptomatic carotid stenosis (ICA stenosis) (CBI + ICA stenosis), (3) 35 patients with CBI but without asymptomatic carotid stenosis, and (4) 20 healthy female volunteers (control group). Intergroup analysis demonstrated that in the group of patients following BC treatment there was a significant increase of ICAM-1 (mean difference: −368.56, 95% CI −450.30 to −286.69, p < 0.001) and PECAM-1 (mean difference: −47.75, 95% CI −68.73 to −26.77, p < 0.001) molecules, as compared to the group of healthy volunteers. Additionally, a decrease of anti-NR-2 antibodies (mean difference: 0.89, 95% CI 0.41 to 1.48, p < 0.001) was detected. The intergroup comparison revealed comparable levels of ICAM-1 (mean difference: −33.58, 95% CI −58.10 to 125.26, p = 0.76), PECAM-1 (mean difference: −5.03, 95% CI −29.93 to 19.87, p = 0.95), as well as anti-NR-2 antibodies (mean difference: −0.05, 95% CI −0.26 to 0.16, p = 0.93) in patients after BC treatment and in patients with CBI + ICA stenosis. The NSE level in the group CBI + ICA stenosis was significantly higher than in women following BC treatment (mean difference: −43.64, 95% CI 3.31 to −83.99, p = 0.03). Comparable levels of ICAM-1 were also detected in patients after BC treatment and in the group of CBI (mean difference: −21.28, 95% CI −111.03 to 68.48, p = 0.92). The level of PECAM-1 molecules in patients after BC treatment was also comparable to group of CBI (mean difference: −13.68, 95% CI −35.51 to 8.15, p = 0.35). In conclusion, among other mechanisms, endothelial dysfunction might play a role in the damage of the CNS in breast cancer survivors.

Adhesion Molecules ICAM-1 and PECAM-1 as Potential Biomarkers of Central Nervous System Damage in Women Breast Cancer Survivors

Breast cancer (BC) is the most common tumor in women worldwide with high mortality rates. Surgical methods followed by radio–chemotherapy are used to treat these tumors. Such treatment can lead to various side effects, including neurological complications. The development of a reliable biomarker to predict the onset of CNS complications could improve clinical outcomes. In the current study, ICAM-1 and PECAM-1 serum levels were measured as potential biomarkers in 45 female patients in a long-term follow-up period after breast cancer treatment, and compared to 25 age-matched female healthy volunteers. Serum levels of both biomarkers, ICAM-1 and PECAM-1 were significantly higher in patients after breast cancer treatment and could be associated with cognitive dysfunction, depression, and vestibulocerebellar ataxia. In conclusion, our results provide a first hint that elevated serum levels of ICAM-1 and PECAM-1 could serve as early predictive biomarkers in breast cancer survivors that might help to improve the management of these patients.

Functional Network Connectivity Reveals the Brain Functional Alterations in Breast Cancer Survivors

Different neurological and psychiatric disorders such as vertebrobasilar insufficiency, chronic pain syndrome, anxiety, and depression are observed in more than 90% of patients after treatment for breast cancer and may cause alterations in the functional connectivity of the default mode network. The purpose of the present study is to assess changes in the functional connectivity of the default mode network in patients after breast cancer treatment using resting state functional magnetic resonance imaging (rs-fMRI). Rs-fMRI was performed using a 3.0T MR-scanner on patients (N = 46, women) with neurological disorders (chronic pain, dizziness, headaches, and/or tinnitus) in the late postoperative period (>12 months) after Patey radical mastectomy for breast cancer. According to the intergroup statistical analysis, there were differences in the functional connectivity of the default mode network in all 46 patients after breast cancer treatment compared to the control group (p < 0.01). The use of rs-fMRI in in breast cancer survivors allowed us to identify changes in the functional connectivity in the brain caused by neurological disorders, which correlated with a decreased quality of life in these patients. The results indicate the necessity to improve treatment and rehabilitation methods in this group of patients.