Clinical implications of lipid peroxides levels in plasma and tumor tissue in breast cancer patients.

Oxidative stress can promote the oxidation of lipoproteins and polyunsaturated fatty acids present in cell membranes; an event known as lipid peroxidation (LPO). LPO has been associated with carcinogenesis and cancer progression, however, its meaning concerning the clinicopathological aspects of human breast cancer is not clear. This study investigated LPO profiles in tumor and plasma samples from breast cancer patients (n = 140) considering their clinicopathological features (age at diagnosis, menopausal status, body mass index, tumor histological grade, tumor size, ki-67 proliferation index, presence of metastasis, chemotherapy response, the molecular subtype of cancer and overall survival status). LPO levels were estimated by tert-butyl hydroperoxide-initiated chemiluminescence. High LPO levels were found regarding poor prognosis parameters as young age at diagnosis (p = 0.006 in tissue), premenopausal patients (p = 0.012 in tissue), high-grade tumors (p = 0.010 in tissue and p = 0.002 in plasma), metastatic disease (p = 0.046 in tissue), chemoresistant tumors (p = 0.041 in tissue), disease relapse (p = 0.018 in tissue and p = 0.009 in plasma) and overall survival status (p = 0.001 in plasma). Our findings point out the clinical meaning of LPO and highlight it as an oxidative stress event linked to poor prognosis and disease aggressiveness in breast cancer patients.

Systemic lipid peroxidation profile from patients with breast cancer changes according to the lymph nodal metastasis status.

Metastasis is the leading cause of cancer death. Considering that lymph nodes are the major pathway for cancer spreading and that the metastatic process is under oxidative stress effects, this study aims to evaluate the differential lipid peroxidation profile in the blood of breast cancer patients regarding their lymph nodal status (LN). A total of 105 women diagnosed with breast cancer were included before chemotherapy started. LN was determined by assessing the histopathological analysis of patients' biopsies, and groups were categorized according to the presence (LN+, n = 48) or absence (LN-, n = 57) of metastases. Lipid peroxidation profiles (LPO) were determined in blood by high-sensitivity chemiluminescence. After patients' categorization in groups according to their clinicopathological features, LN- patients aged over 50 years presented significantly lower LPO when compared to those under 50 years. Further, LN- patients carrying HER2 positive tumors presented augmented LPO when compared to patients bearing luminal B or triple-negative tumors. LN+ group also had reduced LPO when presented intratumoral clots. The significant contribution of this study was to show that LPO correlates with specific clinical features of patients with breast cancer according to their LN status and that such profile is significantly affected by the presence of metastases.